Power System Modeling and Control

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Energies energies	3.0	6.2	2008	16.8 Days	CHF 2600
Mathematics mathematics	2.3	4.0	2013	18.3 Days	CHF 2600
Smart Cities smartcities	7.0	11.2	2018	28.4 Days	CHF 2000

22 pages, 2930 KiB

Open AccessArticle

Turbulent Flow of Water-Based Optimization for Solving Multi-Objective Technical and Economic Aspects of Optimal Power Flow Problems

by Shahenda Sarhan, Ragab El-Sehiemy, Amlak Abaza and Mona Gafar

Mathematics 2022, 10(12), 2106; https://doi.org/10.3390/math10122106 - 17 Jun 2022

Cited by 22 | Viewed by 2110

Abstract

The optimal operation of modern power systems aims at achieving the increased power demand requirements regarding economic and technical aspects. Another concern is preserving the emissions within the environmental limitations. In this regard, this paper aims at finding the optimal scheduling of power [...] Read more.

The optimal operation of modern power systems aims at achieving the increased power demand requirements regarding economic and technical aspects. Another concern is preserving the emissions within the environmental limitations. In this regard, this paper aims at finding the optimal scheduling of power generation units that are able to meet the load requirements based on a multi-objective optimal power flow framework. In the proposed multi-objective framework, objective functions, technical economical, and emissions are considered. The solution methodology is performed based on a developed turbulent flow of a water-based optimizer (TFWO). Single and multi-objective functions are employed to minimize the cost of fuel, emission level, power losses, enhance voltage deviation, and voltage stability index. The proposed algorithm is tested and investigated on the IEEE 30-bus and 57-bus systems, and 17 cases are studied. Four additional cases studied are applied on four large scale test systems to prove the high scalability of the proposed solution methodology. Evaluation of the effectiveness and robustness of the proposed TFWO is proven through a comparison of the simulation results, convergence rate, and statistical indices to other well-known recent algorithms in the literature. We concluded from the current study that TFWO is efficient, effective, robust, and superior in solving OPF optimization problems. It has better convergence rates compared with other well-known algorithms with significant technical and economical improvements. A reduction in the range of 4.6–33.12% is achieved by the proposed TFWO for the large scale tested system. For the tested system, the proposed solution methodology leads to a more competitive solution with significant improvement in the techno-economic aspects. Full article

(This article belongs to the Topic Power System Modeling and Control)

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18 pages, 4999 KiB

Open AccessArticle

Modelling of Battery Energy Storage System Providing FCR in Baltic Power System after Synchronization with the Continental Synchronous Area

by Edgars Groza, Santa Kiene, Olegs Linkevics and Karlis Gicevskis

Energies 2022, 15(11), 3977; https://doi.org/10.3390/en15113977 - 27 May 2022

Cited by 10 | Viewed by 4827

Abstract

This paper presents the case study of provisions of frequency containment reserve (FCR) with a battery electric storage system (BESS). The aim of the case study is the evaluation of the technical possibility to provide FCR in Latvian power systems after all Baltic [...] Read more.

This paper presents the case study of provisions of frequency containment reserve (FCR) with a battery electric storage system (BESS). The aim of the case study is the evaluation of the technical possibility to provide FCR in Latvian power systems after all Baltic power systems will synchronize with the Continental Europe Synchronous Area (CESA). To simulate the dynamics of BESS capacity and its state of charge (SOC), authors have developed an algorithm and mathematical model (it can be realized in different calculation programs). The case study calculations verified the model. The algorithm is conditionally divided into two parts—FCR provision and SOC recovery–which in turn is divided into three possible models of BESS state of charge recovery options: (1) overfulfillment—exceeding the specified FCR amount, (2) deadband utilization, and (3) BESS charging or discharging through scheduled transactions in intraday power market. The modelling was performed using historic frequency data of Latvian and French power systems. The case study of BESS with charging capacity of 12 MW and stored energy volume of 7 MWh for provision of determined FCR for Latvian power system was considered. The obtained results from the simulation were used in the separate model to evaluate economic feasibility of BESS for FCR. Full article

(This article belongs to the Topic Power System Modeling and Control)

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20 pages, 6938 KiB

Open AccessArticle

Multi-Mode Damping Control Approach for the Optimal Resilience of Renewable-Rich Power Systems

by Herlambang Setiadi, Nadarajah Mithulananthan, Rakibuzzaman Shah, Md. Rabiul Islam, Afef Fekih, Awan Uji Krismanto and Muhammad Abdillah

Energies 2022, 15(9), 2972; https://doi.org/10.3390/en15092972 - 19 Apr 2022

Cited by 14 | Viewed by 2428

Abstract

The integration of power-electronics-based power plants is developing significantly due to the proliferation of renewable energy sources. Although this type of power plant could positively affect society in terms of clean and sustainable energy, it also brings adverse effects, especially with the stability [...] Read more.

The integration of power-electronics-based power plants is developing significantly due to the proliferation of renewable energy sources. Although this type of power plant could positively affect society in terms of clean and sustainable energy, it also brings adverse effects, especially with the stability of the power system. The lack of inertia and different dynamic characteristics are the main issues associated with power-electronics-based power plants that could affect the oscillatory behaviour of the power system. Hence, it is important to design a comprehensive damping controller to damp oscillations due to the integration of a power-electronics-based power plant. This paper proposes a damping method for enhancing the oscillatory stability performance of power systems with high penetration of renewable energy systems. A resilient wide-area multimodal controller is proposed and used in conjunction with a battery energy storage system (BESS) to enhance the damping of critical modes. The proposed control also addresses resiliency issues associated with control signals and controllers. The optimal tuning of the control parameters for this proposed controller is challenging. Hence, the firefly algorithm was considered to be the optimisation method to design the wide-area multimodal controllers for BESS, wind, and photovoltaic (PV) systems. The performance of the proposed approach was assessed using a modified version of the Java Indonesian power system under various operating conditions. Both eigenvalue analysis and time-domain simulations are considered in the analysis. A comparison with other well-known metaheuristic methods was also carried out to show the proposed method’s efficacy. Obtained results confirmed the superior performance of the proposed approach in enhancing the small-signal stability of renewable-rich power systems. They also revealed that the proposed multimodal controller could enhance the penetration of renewable energy sources in the Javan power system by up to 50%. Full article

(This article belongs to the Topic Power System Modeling and Control)

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27 pages, 1288 KiB

Open AccessArticle

Adaptive Sliding-Mode Controller for Flyback-Based PV Systems Featuring Constant Switching Frequency

by Carlos Andres Ramos-Paja, Oscar Danilo Montoya and Luis Fernando Grisales-Noreña

Mathematics 2022, 10(8), 1255; https://doi.org/10.3390/math10081255 - 11 Apr 2022

Cited by 5 | Viewed by 2023

Abstract

This paper proposes a sliding-mode controller to ensure both the global stability and maximum power generation of a photovoltaic system based on a flyback converter. The controller is based on an adaptive sliding-surface, which is designed to impose a constant frequency to the [...] Read more.

This paper proposes a sliding-mode controller to ensure both the global stability and maximum power generation of a photovoltaic system based on a flyback converter. The controller is based on an adaptive sliding-surface, which is designed to impose a constant frequency to the switching converter, thus simplifying the selection of both the passive and active elements of the device. Moreover, the controller stability is analyzed using the transversality, reachability and equivalent control conditions. The solution also includes an auto-tuning process for the parameters of the perturb and observe algorithm, which are calculated to ensure the global stability of the sliding-mode controller, thus ensuring the PV system stability. Finally, the performance of the complete solution is verified using detailed circuital simulations of a realistic application case. Full article

(This article belongs to the Topic Power System Modeling and Control)

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15 pages, 4184 KiB

Open AccessArticle

Energy Management Control Strategy for Saving Trip Costs of Fuel Cell/Battery Electric Vehicles

by Juhui Gim, Minsu Kim and Changsun Ahn

Energies 2022, 15(6), 2131; https://doi.org/10.3390/en15062131 - 15 Mar 2022

Cited by 15 | Viewed by 2731

Abstract

Fuel cell vehicles (FCVs) should control the energy management between two energy sources for fuel economy, using the stored energy in a battery or generation of energy through a fuel cell system. The fuel economy for an FCV includes trip costs for hydrogen [...] Read more.

Fuel cell vehicles (FCVs) should control the energy management between two energy sources for fuel economy, using the stored energy in a battery or generation of energy through a fuel cell system. The fuel economy for an FCV includes trip costs for hydrogen consumption and the lifetime of two energy sources. This paper proposes an implementable energy management control strategy for an FCV to reduce trip costs. The concept of the proposed control strategy is first to analyze the allowable current of a fuel cell system from the optimal strategies for various initial battery state of charge (SOC) conditions using dynamic programming (DP), and second, to find a modulation ratio determining the current of a fuel cell system for driving a vehicle using the particle swarm optimization method. The control strategy presents the on/off moment of a fuel cell system and the proper modulation ratio of the turned-on fuel cell system with respect to the battery SOC and the power demand. The proposed strategy reduces trip costs in real-time, similar to the DP-based optimal strategy, and more than the simple energy control strategy of switching a fuel cell system on/off at the battery SOC boundary conditions even for long-term driving cycles. Full article

(This article belongs to the Topic Power System Modeling and Control)

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17 pages, 11533 KiB

Open AccessArticle

Input Small-Signal Characteristics of Selected DC–DC Switching Converters

by Włodzimierz Janke, Maciej Bączek, Jarosław Kraśniewski and Marcin Walczak

Energies 2022, 15(5), 1924; https://doi.org/10.3390/en15051924 - 6 Mar 2022

Cited by 3 | Viewed by 2946

Abstract

The main goal of this study was to derive small-signal models of the input characteristics of buck, boost, and flyback converters working in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The models presented in the paper were derived using the separation [...] Read more.

The main goal of this study was to derive small-signal models of the input characteristics of buck, boost, and flyback converters working in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The models presented in the paper were derived using the separation of variables approach and included the parasitic resistances of all converter components. The paper features a discussion about the limitations of the model accuracy. The presented characteristics were obtained by calculation and verified by measurements. The input characteristics of converters are essential in the design of converters used in Power Factor Correction systems as well as in maximum power point tracking systems (MPPT). Full article

(This article belongs to the Topic Power System Modeling and Control)

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14 pages, 5844 KiB

Open AccessArticle

Control Strategy of Flywheel Energy Storage System Based on Primary Frequency Modulation of Wind Power

by Yu Jia, Zhenkui Wu, Jihong Zhang, Peihong Yang and Zilei Zhang

Energies 2022, 15(5), 1850; https://doi.org/10.3390/en15051850 - 2 Mar 2022

Cited by 18 | Viewed by 3611

Abstract

As a form of energy storage with high power and efficiency, a flywheel energy storage system performs well in the primary frequency modulation of a power grid. In this study, a three-phase permanent magnet synchronous motor was used as the drive motor of [...] Read more.

As a form of energy storage with high power and efficiency, a flywheel energy storage system performs well in the primary frequency modulation of a power grid. In this study, a three-phase permanent magnet synchronous motor was used as the drive motor of the system, and a simulation study on the control strategy of a flywheel energy storage system was conducted based on the primary frequency modulation of wind power. The speed and current double closed-loop control strategy was used in the system start-up phase, and the power and current double-closed-loop control strategy were used in the power compensation phase. The model reference adaptive control was used to accurately estimate the speed and position of the rotor. The system compensates for the wind power output by using a wind turbine in real-time and conducting simulation experiments to verify the feasibility of the charge and discharge control strategy. At the same time, it can be verified that the flywheel energy storage system has a beneficial effect on wind power frequency modulation. Full article

(This article belongs to the Topic Power System Modeling and Control)

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31 pages, 14735 KiB

Open AccessArticle

A Comparison of Frequency-Dependent Soil Models: Electromagnetic Transient Analysis of Overhead Transmission Lines Using Modal Decomposition

by Tainá Fernanda Garbelim Pascoalato, Anderson Ricardo Justo de Araújo, Jaimis Sajid Leon Colqui, Sérgio Kurokawa and José Pissolato Filho

Energies 2022, 15(5), 1687; https://doi.org/10.3390/en15051687 - 24 Feb 2022

Cited by 4 | Viewed by 2471

Abstract

This article investigates the influence of four causal frequency-dependent (FD) soil models and their impact on the responses of a multiphase overhead transmission line (OHTL) with ground wires, generated by a lightning strike. The FD models proposed by Longmire-Smith (LS), Messier (M), Portela [...] Read more.

This article investigates the influence of four causal frequency-dependent (FD) soil models and their impact on the responses of a multiphase overhead transmission line (OHTL) with ground wires, generated by a lightning strike. The FD models proposed by Longmire-Smith (LS), Messier (M), Portela (P) and Alípio-Visacro (AV) are considered. The ground-return impedance and admittance matrices are computed with the Nagakawa approach for both frequency-constant and FD soil models. The frequency-domain modal voltages and time-domain transient voltages are assessed in this work. Modal decomposition technique is used to study the attenuation constant, propagation velocity and voltages for each propagation mode. Simulations are carried out in a frequency range of 100 Hz to 10 MHz, for OHTLs with lengths of 1 and 10 km, on soils of 700 and 4000

Ω

·m. Simulation results demonstrated that the Portela (P) model has resulted in more significant variation in the ground-return impedance and admittance, constant attenuation and propagation velocity in which a pronounced variation, especially at the high frequencies, is seen. On the other hand, Longmire-Smith (LS) and Messier (M) have produced similar results in both frequency and time domains. Additionally, the Alípio-Visacro (AV) model has produced intermediate responses, being the model recommended by CIGRÈ WG C4.33. Time-domain induced voltage waveforms obtained with the Portela (P) model has shown pronounced differences, especially at the peak values, for the high-resistive soil. This study demonstrates the importance of considering the FD soil models to assess the transient responses adequately, especially when OHTLs are on high-resistive soils. Full article

(This article belongs to the Topic Power System Modeling and Control)

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15 pages, 5977 KiB

Open AccessArticle

Composite Non-Linear Control of Hybrid Energy-Storage System in Electric Vehicle

by Zhangyu Lu and Xizheng Zhang

Energies 2022, 15(4), 1567; https://doi.org/10.3390/en15041567 - 21 Feb 2022

Cited by 9 | Viewed by 2220

Abstract

The underlying circuit control is a key problem of the hybrid energy-storage system (HESS) in electric vehicles (EV). In this paper, a composite non-linear control strategy (CNC) is proposed for the accurate tracking current/voltage of the fully-active HESS by combining the exact feedback [...] Read more.

The underlying circuit control is a key problem of the hybrid energy-storage system (HESS) in electric vehicles (EV). In this paper, a composite non-linear control strategy (CNC) is proposed for the accurate tracking current/voltage of the fully-active HESS by combining the exact feedback linearization method and the sliding mode variable structure control technology. Firstly, by analyzing the circuit characteristics of HESS, the affine non-linear model of fully-active HESS is derived. Then, a rule-based energy management strategy (EMS) is designed to generate the reference current value. Finally, the HESS is linearized by the exact feedback linearization method, and the proposed CNC strategy is developed combined with sliding mode variable structure control technology to ensure fast response, high performance, and robustness. At the same time, the stability proof based on the Lyapunov method is given. Moreover, the performance of the CNC strategy is thoroughly investigated and compared with simulation studies with the traditional PI control and a modified sliding mode control, and its effectiveness under different driving conditions is fully verified. Full article

(This article belongs to the Topic Power System Modeling and Control)

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15 pages, 877 KiB

Open AccessArticle

Optimal Design of Automatic Generation Control Based on Simulated Annealing in Interconnected Two-Area Power System Using Hybrid PID—Fuzzy Control

by Muntasir A. Magzoub and Thamer Alquthami

Energies 2022, 15(4), 1540; https://doi.org/10.3390/en15041540 - 19 Feb 2022

Cited by 28 | Viewed by 6043

Abstract

Electricity demand continues to rise on a daily basis. The most difficult task is ensuring that customers have access to reliable, high-quality electricity regardless of the weather. Automatic generation control (AGC) accomplishes this by keeping the target output power and frequency constant despite [...] Read more.

Electricity demand continues to rise on a daily basis. The most difficult task is ensuring that customers have access to reliable, high-quality electricity regardless of the weather. Automatic generation control (AGC) accomplishes this by keeping the target output power and frequency constant despite load fluctuations. This paper presents a hybrid PID-fuzzy controller for optimal automatic generation control in a two-area interconnected power system. A comparative analysis of the proposed controller was performed with the PID controller. The parameters of the both controllers were developed by simulated annealing (SA) techniques in order to obtain the best dynamic performance. MATLAB Simulink software was used to simulate the models. The results of the simulation for the two-area power system based on simulated annealing using the hybrid PID–fuzzy controller showed superior performance in comparison to a conventional PID controller. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 1299 KiB

Open AccessArticle

Analytical Energy Model Parametrized by Workload, Clock Frequency and Number of Active Cores for Share-Memory High-Performance Computing Applications

by Vitor Ramos Gomes da Silva, Carlos Valderrama, Pierre Manneback and Samuel Xavier-de-Souza

Energies 2022, 15(3), 1213; https://doi.org/10.3390/en15031213 - 7 Feb 2022

Cited by 3 | Viewed by 2721

Abstract

Energy consumption is crucial in high-performance computing (HPC), especially to enable the next exascale generation. Hence, modern systems implement various hardware and software features for power management. Nonetheless, due to numerous different implementations, we can always push the limits of software to achieve [...] Read more.

Energy consumption is crucial in high-performance computing (HPC), especially to enable the next exascale generation. Hence, modern systems implement various hardware and software features for power management. Nonetheless, due to numerous different implementations, we can always push the limits of software to achieve the most efficient use of our hardware. To be energy efficient, the software relies on dynamic voltage and frequency scaling (DVFS), as well as dynamic power management (DPM). Yet, none have privileged information on the hardware architecture and application behavior, which may lead to energy-inefficient software operation. This study proposes analytical modeling for architecture and application behavior that can be used to estimate energy-optimal software configurations and provide knowledgeable hints to improve DVFS and DPM techniques for single-node HPC applications. Additionally, model parameters, such as the level of parallelism and dynamic power, provide insights into how the modeled application consumes energy, which can be helpful for energy-efficient software development and operation. This novel analytical model takes the number of active cores, the operating frequencies, and the input size as inputs to provide energy consumption estimation. We present the modeling of 13 parallel applications employed to determine energy-optimal configurations for several different input sizes. The results show that up to 70% of energy could be saved in the best scenario compared to the default Linux choice and 14% on average. We also compare the proposed model with standard machine-learning modeling concerning training overhead and accuracy. The results show that our approach generates about 10 times less energy overhead for the same level of accuracy. Full article

(This article belongs to the Topic Power System Modeling and Control)

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17 pages, 2684 KiB

Open AccessArticle

Evaluation of an Additional Generator on the Economic Effect Based on a Load Sharing Optimization of Medium-Speed/High-Speed Diesel Generators in a Microgrid

by Shuhei Yamano and Atsushi Akisawa

Energies 2022, 15(3), 1007; https://doi.org/10.3390/en15031007 - 29 Jan 2022

Viewed by 2240

Abstract

This study investigates the additional installation of a high-speed diesel generator to independent microgrids (MG) such as remote islands where relatively efficient medium-speed diesel generators (DGs) are mainly used. While small-sized and lightweight, high-speed DGs are not widely spread for continuous usage because [...] Read more.

This study investigates the additional installation of a high-speed diesel generator to independent microgrids (MG) such as remote islands where relatively efficient medium-speed diesel generators (DGs) are mainly used. While small-sized and lightweight, high-speed DGs are not widely spread for continuous usage because their efficiency is lower than that of the medium-speed DGs. The objective of this study is to evaluate the performance of the new method of load sharing optimization to improve the economy by interconnecting a high-speed DG to an independent MG where the medium-speed DGs are operated. The study investigates the effect of operation cost reduction by installing the new load sharing method of operation following the load sharing pattern derived by the mixed-integer programming. As a result of this study, there was some effect to installing a high-speed DG operated by the conventional method. In addition, by adding the new method of load sharing with optimization, the economic effect became even higher. Full article

(This article belongs to the Topic Power System Modeling and Control)

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17 pages, 8689 KiB

Open AccessArticle

A New Design of MP-HDCCB Topology Based on Hybrid Switching Device

by Haipeng Jia, Jingyuan Yin, Tongzhen Wei, Jinke Li, Jin Zhu and Zeyu Ye

Energies 2022, 15(3), 903; https://doi.org/10.3390/en15030903 - 26 Jan 2022

Cited by 1 | Viewed by 2612

Abstract

Since each branch of the multiterminal DC circuit system relies on the DC circuit breaker for breaking and fault isolation, the prohibitive cost and huge volume of the Hybrid DC Circuit Breaker (HCB) limit its development and broad application in multiterminal flexible DC [...] Read more.

Since each branch of the multiterminal DC circuit system relies on the DC circuit breaker for breaking and fault isolation, the prohibitive cost and huge volume of the Hybrid DC Circuit Breaker (HCB) limit its development and broad application in multiterminal flexible DC systems. Multiport hybrid DC circuit breaker (MP-HDCCB) based on device and branch sharing reduces the configuration cost of the circuit breaker to a certain extent. In order to further reduce the cost of MP-HDCCB, a novel MP-HDCCB topology based on hybrid switching devices is proposed, adopting full controlled switching devices to achieve rapidity of breaking fault current, and using semi-controlled switching devices in series to withstand the transient interruption voltage (TIV), so as to reduce the construction cost and technical difficulty. In this paper, the working principle and fault breaking strategy of the topology are introduced in detail, then the parameters of the major circuit are analyzed theoretically, and the parameter design of each branch is given. In the end, the rationality and validity of the proposed topology is tested and verified by simulations and experimental tests. Full article

(This article belongs to the Topic Power System Modeling and Control)

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25 pages, 7796 KiB

Open AccessArticle

High Performance Single and Double Loop Digital and Hybrid PID-Type Control for DC/AC Voltage Source Inverters

by Marian Blachuta, Robert Bieda and Rafal Grygiel

Energies 2022, 15(3), 785; https://doi.org/10.3390/en15030785 - 21 Jan 2022

Cited by 1 | Viewed by 2234

Abstract

The concept of hybrid control has been introduced, in which the analog implementation of the control algorithm is combined with a digital algorithm for determining the PWM duty cycle. Single-loop PD and PID control systems are compared to a double-loop architecture with additional [...] Read more.

The concept of hybrid control has been introduced, in which the analog implementation of the control algorithm is combined with a digital algorithm for determining the PWM duty cycle. Single-loop PD and PID control systems are compared to a double-loop architecture with additional capacitor current sensing for both digital and hybrid controller realizations. The performance is measured as the THD value under resistor-capacitor rectifier load. It has been shown that a properly constructed continuous-time model of a digital controller with a PWM power converter behaves like the actual discrete-time system, which allows for a simple controller analysis and design. The role of a PWM type for capacitor current feedback is emphasized. The simulation models of a real inverter are presented, which are used to tune the controllers and to evaluate the control performance for both rectifier and abruptly changing resistive load. The obtained solutions achieve the THD values comparable to the VSI without load. The results are contrasted with the control methods based on resonant filters. Full article

(This article belongs to the Topic Power System Modeling and Control)

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21 pages, 6435 KiB

Open AccessArticle

Modeling and Design Optimization of Energy Transfer Rate for Hybrid Energy Storage System in Electromagnetic Launch

by Tao Ma, Junyong Lu, Xiao Zhang, Bofeng Zhu, Wenxuan Wu and Xinlin Long

Energies 2022, 15(3), 695; https://doi.org/10.3390/en15030695 - 18 Jan 2022

Cited by 2 | Viewed by 1820

Abstract

The battery-pulse capacitor-based hybrid energy storage system has the advantage of high-energy density and high-power density. However, to achieve a higher firing rate of the electromagnetic launch, a shorter charging time of the pulse capacitor from the battery is needed. A new optimization [...] Read more.

The battery-pulse capacitor-based hybrid energy storage system has the advantage of high-energy density and high-power density. However, to achieve a higher firing rate of the electromagnetic launch, a shorter charging time of the pulse capacitor from the battery is needed. A new optimization model by formulating the charging time problem as a constrained optimization problem is presented. Unlike existing algorithms, the proposed model can find the globally optimal solution. The circuit parameters are optimized through the Enumeration algorithm to minimize the total charging time of the pulse capacitors from batteries. The simulation results show that the charging time of the proposed algorithm is shorter than the compared methods. Furthermore, a better solution could be obtained by canceling the constraint on the first peak of the charging current of the compared methods, which makes the circuit design more flexible for the hybrid energy storage system in the electromagnetic launch. Full article

(This article belongs to the Topic Power System Modeling and Control)

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19 pages, 44637 KiB

Open AccessArticle

Adaptive Fuzzy Neural Network PID Algorithm for BLDCM Speed Control System

by Hongqiao Yin, Wenjun Yi, Jintao Wu, Kangjian Wang and Jun Guan

Mathematics 2022, 10(1), 118; https://doi.org/10.3390/math10010118 - 31 Dec 2021

Cited by 18 | Viewed by 4118

Abstract

Because of its simple structure, high efficiency, low noise, and high reliability, the brushless direct current motor (BLDCM) has an irreplaceable role compared with other types of motors in many aspects. The traditional proportional integral derivative (PID) control algorithm has been widely used [...] Read more.

Because of its simple structure, high efficiency, low noise, and high reliability, the brushless direct current motor (BLDCM) has an irreplaceable role compared with other types of motors in many aspects. The traditional proportional integral derivative (PID) control algorithm has been widely used in practical engineering because of its simple structure and convenient adjustment, but it has many shortcomings in control accuracy and other aspects. Therefore, in this paper, a fuzzy single neuron neural network (FSNNN) PID algorithm based on an automatic speed regulator (ASR) is designed and applied to a BLDCM control system. This paper introduces a BLDCM mathematical model and its control system and designs an FSNNN PID algorithm that takes speed deviation e at different sampling times as inputs of a neural network to adjust the PID parameters, and then it uses a fuzzy system to adjust gain K of the neural network. In addition, the frequency domain stability of a double closed loop PID control system is analyzed, and the control effect of traditional PID, fuzzy PID, and FSNNN PID algorithms are compared by setting different reference speeds, as well as the change rules of three-phase current, back electromotive force (EMF), electromagnetic torque, and rotor angle position. Finally, results show that a motor controlled by the FSNNN PID algorithm has certain superiority compared with traditional PID and fuzzy PID algorithms and also has better control effects. Full article

(This article belongs to the Topic Power System Modeling and Control)

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15 pages, 5512 KiB

Open AccessArticle

A Review on Optimal Control for the Smart Grid Electrical Substation Enhancing Transition Stability

by Wilson Pavon, Esteban Inga, Silvio Simani and Maddalena Nonato

Energies 2021, 14(24), 8451; https://doi.org/10.3390/en14248451 - 14 Dec 2021

Cited by 23 | Viewed by 4637

Abstract

This paper is a research article for finding the optimal control of smart power substations for improving the network parameters and reliability. The included papers are the most essential and main studies in the field, which propose a different approach to reach the [...] Read more.

This paper is a research article for finding the optimal control of smart power substations for improving the network parameters and reliability. The included papers are the most essential and main studies in the field, which propose a different approach to reach the best performance in electrical power systems. The parameters for improvement are the ability for tracking of the reference signal, stabilizing the system, reducing the error in steady state and controlling the behavior in transient state. The research focuses with the reaching a better transient stability considering voltage and frequency dynamic parameters. The optimal model for the control is focused on minimizing energy consumption but maintaining the controllable parameters, exploring some optimization techniques to find the optimal control, with of aim of minimizing the response time, the energy consumption, and maximizing the reliability by means of improving the controller to be more robust. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 5121 KiB

Open AccessArticle

Analysis of Stationary- and Synchronous-Reference Frames for Three-Phase Three-Wire Grid-Connected Converter AC Current Regulators

by Israel D. L. Costa, Danilo I. Brandao, Lourenço Matakas Junior, Marcelo G. Simões and Lenin M. F. Morais

Energies 2021, 14(24), 8348; https://doi.org/10.3390/en14248348 - 10 Dec 2021

Cited by 10 | Viewed by 5736

Abstract

The current state of the art shows that unbalance and distortion on the voltage waveforms at the terminals of a grid-connected inverter disturb its output currents. This paper compares AC linear current regulators for three-phase three-wire voltage source converters with three different reference [...] Read more.

The current state of the art shows that unbalance and distortion on the voltage waveforms at the terminals of a grid-connected inverter disturb its output currents. This paper compares AC linear current regulators for three-phase three-wire voltage source converters with three different reference frames, namely: (1) natural (abc), (2) orthogonal stationary (αβ), and (3) orthogonal synchronous (dq). The quantitative comparison analysis is based on mathematical models of grid disturbances using the impedance-based analysis, the computational effort assessment, as well as the steady-state and transient performance evaluation based on experimental results. The control scheme devised in the dq-frame has the highest computational effort and inferior performance under negative-sequence voltage disturbances, whereas it shows superior performance under positive-sequence voltages among the reference frames evaluated. In contrast, the stationary natural frame abc has the lowest computational effort due to its straightforward implementation, with similar results in terms of steady-state and transient behavior. The αβ-frame is an intermediate solution in terms of computational cost. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 5773 KiB

Open AccessArticle

Analyses and Comparisons of Generic and User Writing Models of HVDC System Considering Transient DC Current and Voltages

by Dohoon Kwon and Youngjin Kim

Energies 2021, 14(23), 7897; https://doi.org/10.3390/en14237897 - 25 Nov 2021

Cited by 2 | Viewed by 2811

Abstract

Analyses and comparisons of generic models and a novel modeling method of line-commutated converter (LCC)-based high voltage direct current (HVDC) systems are presented for the power system simulator for engineering (PSS/E) simulation tool. The main purposes are to describe the dynamics of the [...] Read more.

Analyses and comparisons of generic models and a novel modeling method of line-commutated converter (LCC)-based high voltage direct current (HVDC) systems are presented for the power system simulator for engineering (PSS/E) simulation tool. The main purposes are to describe the dynamics of the DC voltage and current of HVDC system and to improve estimation of the maximum values using the generic and proposed HVDC models when AC line-to-ground faults are occurred. For the generic HVDC models, the characteristics and limitations as well as parameter investigations are conducted. Three modules are also are developed for the proposed HVDC model, which are composed of (a) AC/DC conversion; (b) controller selection; and (c) DC line model. Case studies were conducted considering the real-operated HVDC system in Korea under the PSS/E and power systems computer aided design (PSCAD) simulation environments. The simulation results were compared with measured data from the real-operated HVDC system and the results from the PSCAD HVDC models considering single- and three-phase line-to-ground faults. The case study results show that a specific generic HVDC model in PSS/E can simulate the dynamics of the DC voltage and current after the AC line-to-ground faults. The case studies also showed that the proposed modeling method is effectively improves the estimation of the maximum DC voltage and current values for the AC line-to-ground faults. Full article

(This article belongs to the Topic Power System Modeling and Control)

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28 pages, 6937 KiB

Open AccessArticle

Studies on Energy Consumption of Electric Light Commercial Vehicle Powered by In-Wheel Drive Modules

by Piotr Szewczyk and Andrzej Łebkowski

Energies 2021, 14(22), 7524; https://doi.org/10.3390/en14227524 - 11 Nov 2021

Cited by 8 | Viewed by 4274

Abstract

This article presents the results of energy consumption research for an electric light commercial vehicle (eLCV) powered by a centrally located motor (4 × 2 drive system) or motors placed in the vehicle’s wheels (4 × 4 drive system). For the considered constructions [...] Read more.

This article presents the results of energy consumption research for an electric light commercial vehicle (eLCV) powered by a centrally located motor (4 × 2 drive system) or motors placed in the vehicle’s wheels (4 × 4 drive system). For the considered constructions of electric drive systems, mathematical models of 4 × 2 and 4 × 4 drive systems were developed in the Modelica simulation environment, based on real data. Additionally, the influence of changes in the vehicle loading condition on the operation of the motor mounted in the wheel and the energy consumption of the drive module was investigated. On the basis of the conducted research, a comparative analysis of energy consumption by electric drive systems in 4 × 2 and 4 × 4 configurations was carried out for selected test cycles. The tests carried out with the Worldwide harmonized Light vehicles Test Cycles (WLTC) test cycle showed a roughly 6% lower energy consumption by the 4 × 4 drive system compared to the 4 × 2 configuration. Full article

(This article belongs to the Topic Power System Modeling and Control)

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26 pages, 2368 KiB

Open AccessReview

A Comprehensive Review of Small-Signal Stability and Power Oscillation Damping through Photovoltaic Inverters

by Nikolay Nikolaev, Kiril Dimitrov and Yulian Rangelov

Energies 2021, 14(21), 7372; https://doi.org/10.3390/en14217372 - 5 Nov 2021

Cited by 14 | Viewed by 4335

Abstract

This paper focuses on the methods that ensure the rotor angle stability of electric power systems, which is most frequently analyzed with small-signal models. Over the past several decades, power system stabilizers (PSSs) for conventional excitation systems were the main tools for improving [...] Read more.

This paper focuses on the methods that ensure the rotor angle stability of electric power systems, which is most frequently analyzed with small-signal models. Over the past several decades, power system stabilizers (PSSs) for conventional excitation systems were the main tools for improving the small-signal stability of electromechanical oscillatory modes. In the last decade, power oscillation damping (POD) control implemented in photovoltaic (PV) inverters has been considered an alternative to PSSs. As PV generation undergoes massive rollout due to policy directions and renewable energy source integration activities, it could potentially be used as a source of damping, which is crucial for sustaining the rotor angle stability of the remaining in-service synchronous generators. Several studies have already been dedicated to the development of different damping strategies. This paper contributes to the existing research in power system stability by providing a comprehensive review of the effects of PV generation on small-signal stability, as well as the recent evolution of POD control through PV inverters. The features and impacts of the various ways to realize POD controllers are assessed and summarized in this paper. Currently, detailed information and discussions on the practical application of PV inverter PODs are not available. This paper is, thus, intended to initiate a relevant discussion and propose possible implementation approaches concerning the topic under study. Full article

(This article belongs to the Topic Power System Modeling and Control)

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14 pages, 1404 KiB

Open AccessArticle

An Efficient Chameleon Swarm Algorithm for Economic Load Dispatch Problem

by Mokhtar Said, Ali M. El-Rifaie, Mohamed A. Tolba, Essam H. Houssein and Sanchari Deb

Mathematics 2021, 9(21), 2770; https://doi.org/10.3390/math9212770 - 1 Nov 2021

Cited by 52 | Viewed by 2992

Abstract

Economic Load Dispatch (ELD) is a complicated and demanding problem for power engineers. ELD relates to the minimization of the economic cost of production, thereby allocating the produced power by each unit in the most possible economic manner. In recent years, emphasis has [...] Read more.

Economic Load Dispatch (ELD) is a complicated and demanding problem for power engineers. ELD relates to the minimization of the economic cost of production, thereby allocating the produced power by each unit in the most possible economic manner. In recent years, emphasis has been laid on minimization of emissions, in addition to cost, resulting in the Combined Economic and Emission Dispatch (CEED) problem. The solutions of the ELD and CEED problems are mostly dominated by metaheuristics. The performance of the Chameleon Swarm Algorithm (CSA) for solving the ELD problem was tested in this work. CSA mimics the hunting and food searching mechanism of chameleons. This algorithm takes into account the dynamics of food hunting of the chameleon on trees, deserts, and near swamps. The performance of the aforementioned algorithm was compared with a number of advanced algorithms in solving the ELD and CEED problems, such as Sine Cosine Algorithm (SCA), Grey Wolf Optimization (GWO), and Earth Worm Algorithm (EWA). The simulated results established the efficacy of the proposed CSA algorithm. The power mismatch factor is the main item in ELD problems. The best value of this factor must tend to nearly zero. The CSA algorithm achieves the best power mismatch values of

3.16 \times 10^{- 13}

,

4.16 \times 10^{- 12}

and

1.28 \times 10^{- 12}

for demand loads of 700, 1000, and 1200 MW, respectively, of the ELD problem. The CSA algorithm achieves the best power mismatch values of

6.41 \times 10^{- 13}

,

8.92 \times 10^{- 13} and 1.68 \times 10^{- 12}

for demand loads of 700, 1000, and 1200 MW, respectively, of the CEED problem. Thus, the CSA algorithm was found to be superior to the algorithms compared in this work. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 8078 KiB

Open AccessArticle

Multi-Objective Decentralized Model Predictive Control for Inverter Air Conditioner Control of Indoor Temperature and Frequency Stabilization in Microgrid

by Jonglak Pahasa, Potejanasak Potejana and Issarachai Ngamroo

Energies 2021, 14(21), 6969; https://doi.org/10.3390/en14216969 - 23 Oct 2021

Cited by 2 | Viewed by 2321

Abstract

Microgrid (MG) is a novel concept for a future distribution power system that enables renewable energy sources (RES). The intermittent RES, such as wind turbines and photovoltaic generators, can be connected to the MG via a power electronics inverter. However, the inverter interfaced [...] Read more.

Microgrid (MG) is a novel concept for a future distribution power system that enables renewable energy sources (RES). The intermittent RES, such as wind turbines and photovoltaic generators, can be connected to the MG via a power electronics inverter. However, the inverter interfaced RESs reduce the total inertia and damping properties of the traditional MG. Consequently, the system exhibits steeper frequency nadir and the rate of change of frequency (RoCoF), which may degrade the dynamic performance and cause the severe frequency fluctuation of the system. Smart loads such as inverter air conditioners (IACs) tend to be used for ancillary services in power systems. The power consumption of IACs can be regulated to suppress frequency fluctuation. Nevertheless, these IACs, regulating power, can cause the deviation of indoor temperature from the temperature setting. The variation in indoor temperature should be controlled to fulfill residential comfort. This paper proposes a multi-objective decentralized model predictive control (DMPC) for controlling the power consumption of IACs to reduce MG frequency fluctuation and control the variation in indoor temperature. Simulation results on the studied microgrid with the high penetration of wind and photovoltaic generator demonstrate that the proposed DMPC is able to regulate frequency deviation and control indoor temperature deviation as a user preference. In addition, the DMPC has a superior performance effect to the proportional-integral (PI) controller in terms of reducing frequency deviation, satisfying indoor temperature preferences, and being robust to the varying numbers of IACs. Full article

(This article belongs to the Topic Power System Modeling and Control)

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21 pages, 3863 KiB

Open AccessArticle

Power Quality Improvement through a UPQC and a Resonant Observer-Based MIMO Control Strategy

by Holman Bueno-Contreras, Germán Andrés Ramos and Ramon Costa-Castelló

Energies 2021, 14(21), 6938; https://doi.org/10.3390/en14216938 - 21 Oct 2021

Cited by 7 | Viewed by 3235

Abstract

Performance degradation is, in general, regarded as a power quality problem. One solution to recover grid performance is through the application of a unified power quality conditioner (UPQC). Although these devices are multi-input/multi-output (MIMO) systems, the most common control strategies consist of two [...] Read more.

Performance degradation is, in general, regarded as a power quality problem. One solution to recover grid performance is through the application of a unified power quality conditioner (UPQC). Although these devices are multi-input/multi-output (MIMO) systems, the most common control strategies consist of two decoupled controllers, which neglect the coupling effects and add uncertainty to the system. For this reason, this paper proposes a multivariable resonant observer-based control strategy of a UPQC system. This method includes all significant coupling effects between this system and the grid. This strategy results in a stability-based compensator, which differs from recently proposed strategies that are based on signal calculation and cannot assure closed-loop stability. In addition, this paper introduces a simplified controller tuning strategy based on optimal conventional methods without losing closed-loop performance. It implies that the controller can be easily tuned, despite the complexity of the MIMO dynamic model. The UPQC with the resonant observer is verified on an experimental setup for a single-phase system, obtaining three relevant results for power quality improvement: (1) harmonics compensation tested with a total harmonic distortion limit of 5%; (2) sags and swells mitigation; and (3) power factor correction, achieving a unitary value on the grid side. Full article

(This article belongs to the Topic Power System Modeling and Control)

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11 pages, 4491 KiB

Open AccessArticle

Analysis of the Transformer Characteristics for an Integration System with a Wireless Power Transfer Device and Linear Motor

by Hwajin Woo, Jang-Hyun Park, Changdae Joo, Hokyun Ahn, Dohyun Kang and Taekue Kim

Energies 2021, 14(20), 6769; https://doi.org/10.3390/en14206769 - 17 Oct 2021

Cited by 2 | Viewed by 2251

Abstract

This paper proposed the transformer characteristic analysis method for the wireless power transfer (WPT) device and linear motor (LM) integration system that can be applied to industrial cleanroom transfer systems. A cable is required to supply the power in conventional systems. In comparison, [...] Read more.

This paper proposed the transformer characteristic analysis method for the wireless power transfer (WPT) device and linear motor (LM) integration system that can be applied to industrial cleanroom transfer systems. A cable is required to supply the power in conventional systems. In comparison, the proposed system utilizes a WPT device that can simplify power transfers and make a better space utilization. The shape of the wireless power transmission system is proposed along with the discussion of the 2D FEA analysis method about the inductance analyzing method, which are important parameters in magnetic coupling. In addition, ferrite iron loss was calculated based on the analysis results, and applied to the entire modeling circuit to verify the validity of the measured and analyzed values. Finally, the proposed analysis method for the transformer coupling characteristics of the wireless power transfer combined with the transfer system is verified by experiments and simulations. Full article

(This article belongs to the Topic Power System Modeling and Control)

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19 pages, 4914 KiB

Open AccessArticle

Calculating the Inrush Current of Superconducting Transformers

by Grzegorz Komarzyniec

Energies 2021, 14(20), 6714; https://doi.org/10.3390/en14206714 - 15 Oct 2021

Cited by 8 | Viewed by 2590

Abstract

Under certain circumstances, after connecting a superconducting transformer to the power network, a high value current may flow through its windings. This current can exceed the critical value of the superconductor many times and cause the windings to lose their superconductive state. Loss [...] Read more.

Under certain circumstances, after connecting a superconducting transformer to the power network, a high value current may flow through its windings. This current can exceed the critical value of the superconductor many times and cause the windings to lose their superconductive state. Loss of superconductive state of the windings may result in thermal interruption of their continuity as a result of conduction of a current of very high density. The mathematical relationships used to calculate the inrush current of conventional transformers do not work well for the calculation of superconducting transformers. This is due to the properties of superconducting materials used in the windings, first of all to the stepwise changes of the windings’ resistance when exiting the superconducting state and when returning to this state. The article presents the mathematical dependencies allowing to calculate the pulse waveforms of the inrush current of these transformers are derived. Basic electrical circuit sizes are used in the calculations, making the calculations quick and easy. Using the formulas, calculations of the inrush current of 8.5 kVA and 13.5 kVA superconducting transformers. The results were verified with the results of the inrush current measurements, achieving good compliance. Full article

(This article belongs to the Topic Power System Modeling and Control)

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30 pages, 3570 KiB

Open AccessArticle

Pressure Retarded Osmosis Power Units Modelling for Power Flow Analysis of Electric Distribution Networks

by Mario Llamas-Rivas, Alejandro Pizano-Martínez, Claudio R. Fuerte-Esquivel, Luis R. Merchan-Villalba, José M. Lozano-García, Enrique A. Zamora-Cárdenas and Víctor J. Gutiérrez-Martínez

Energies 2021, 14(20), 6649; https://doi.org/10.3390/en14206649 - 14 Oct 2021

Viewed by 2430

Abstract

Pressure retarded osmosis (PRO) power units, which produce electrical energy from salinity gradient sources located at coastlines, are a technology still in the process of maturation; however, there is an expectation that this technology will need to be integrated into electrical distribution networks. [...] Read more.

Pressure retarded osmosis (PRO) power units, which produce electrical energy from salinity gradient sources located at coastlines, are a technology still in the process of maturation; however, there is an expectation that this technology will need to be integrated into electrical distribution networks. Such integration will drive changes in the electric response of the distribution systems which may lead to harmful operating conditions. Power flow analysis is a tool used to reveal the steady-state operating condition of distribution systems and which could be extended to study and address the integration of PRO power units. To the best of the authors’ knowledge, such extension of power flow analysis has not yet been addressed in the literature. Accordingly, this paper comprehensively provides a model to evaluate the electric current and complex power produced by PRO power units. This model is directly embedded in the forward-backward sweep (FBS) method, extending the power flow analysis of electric distribution systems in this way so as to consider the integration of PRO power units. The resulting approach permits revealing of the steady-state operating response of distribution systems and the effects that may be driven by the integration of PRO power units, as corroborated through numerical results on a 14-node test distribution system. Full article

(This article belongs to the Topic Power System Modeling and Control)

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20 pages, 10131 KiB

Open AccessArticle

Optimization of Lumped Parameter Models to Mitigate Numerical Oscillations in the Transient Responses of Short Transmission Lines

by Jaimis S. L. Colqui, Anderson R. J. de Araújo, Sérgio Kurokawa and José Pissolato Filho

Energies 2021, 14(20), 6534; https://doi.org/10.3390/en14206534 - 12 Oct 2021

Cited by 6 | Viewed by 2048

Abstract

The Lumped Parameter Model (LPM) is a known approach to represent overhead transmission lines (TLs), especially when these elements comprehend a few tens of kilometers. LPMs employ a large number of cascaded

π

-circuits to compute accurately the transient responses. These responses contain [...] Read more.

The Lumped Parameter Model (LPM) is a known approach to represent overhead transmission lines (TLs), especially when these elements comprehend a few tens of kilometers. LPMs employ a large number of cascaded

π

-circuits to compute accurately the transient responses. These responses contain numerical spurious oscillations (NSO) characterized by erroneous peaks which distort the transient responses, mainly their peak values. Two modified LPM topologies composed of damping resistances inserted along the longitudinal or transversal branches of the cascaded

π

-circuits offer significant mitigations in the NSO. In this paper, in an effort to have the maximum mitigation of the NSO and low distortion in the transient responses, two modified topologies with optimized damping resistances are proposed to represent short TLs. Results demonstrate expressive attenuation in the peaks of NSO which reflect good agreement in comparison with the responses computed by the Bergeron’s line model. The mitigation of the NSO is carried out directly in the time domain and it does not require either analog or digital filters.Furthermore, no frequency-to-time transformations are necessary in this procedure. These alternative topologies can be incorporated into any electromagnetic transient program to study switching operations in power systems. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 39437 KiB

Open AccessArticle

An Anti-Fluctuation Compensator Design and Its Control Strategy for Wind Farm System

by Feng-Chang Gu and Hung-Cheng Chen

Energies 2021, 14(19), 6413; https://doi.org/10.3390/en14196413 - 7 Oct 2021

Cited by 1 | Viewed by 2274

Abstract

Large-scale wind farms in commercial operations have demonstrated growing influence on the stability of an electricity network and the power quality thereof. Variations in the output power of large-scale wind farms cause voltage fluctuations in the corresponding electrical networks. To achieve low-voltage ride-through [...] Read more.

Large-scale wind farms in commercial operations have demonstrated growing influence on the stability of an electricity network and the power quality thereof. Variations in the output power of large-scale wind farms cause voltage fluctuations in the corresponding electrical networks. To achieve low-voltage ride-through capability in a doubly fed induction generator (DFIG) during a fault event, this study proposes a real-time reactive power control strategy for effective DFIG application and a static synchronous compensator (STATCOM) for reactive power compensation. Mathematic models were developed for the DFIG and STATCOM, followed by the development of an indirect control scheme for the STATCOM based on decoupling dual-loop current control. Moreover, a real-world case study on a commercial wind farm comprising 23 DFIGs was conducted. The voltage regulation performance of the proposed reactive power control scheme against a fault event was also simulated. The simulation results revealed that enhanced fault ride-through capability and prompt recovery of the output voltage provided by a wind turbine generator could be achieved using the DFIG along with the STATCOM in the event of a three-phase short-circuit fault. Full article

(This article belongs to the Topic Power System Modeling and Control)

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42 pages, 10995 KiB

Open AccessArticle

Machine Learning and Data Segmentation for Building Energy Use Prediction—A Comparative Study

by William Mounter, Chris Ogwumike, Huda Dawood and Nashwan Dawood

Energies 2021, 14(18), 5947; https://doi.org/10.3390/en14185947 - 18 Sep 2021

Cited by 9 | Viewed by 3429

Abstract

Advances in metering technologies and emerging energy forecast strategies provide opportunities and challenges for predicting both short and long-term building energy usage. Machine learning is an important energy prediction technique, and is significantly gaining research attention. The use of different machine learning techniques [...] Read more.

Advances in metering technologies and emerging energy forecast strategies provide opportunities and challenges for predicting both short and long-term building energy usage. Machine learning is an important energy prediction technique, and is significantly gaining research attention. The use of different machine learning techniques based on a rolling-horizon framework can help to reduce the prediction error over time. Due to the significant increases in error beyond short-term energy forecasts, most reported energy forecasts based on statistical and machine learning techniques are within the range of one week. The aim of this study was to investigate how facility managers can improve the accuracy of their building’s long-term energy forecasts. This paper presents an extensive study of machine learning and data processing techniques and how they can more accurately predict within different forecast ranges. The Clarendon building of Teesside University was selected as a case study to demonstrate the prediction of overall energy usage with different machine learning techniques such as polynomial regression (PR), support vector regression (SVR) and artificial neural networks (ANNs). This study further examined how preprocessing training data for prediction models can impact the overall accuracy, such as via segmenting the training data by building modes (active and dormant), or by days of the week (weekdays and weekends). The results presented in this paper illustrate a significant reduction in the mean absolute percentage error (MAPE) for segmented building (weekday and weekend) energy usage prediction when compared to unsegmented monthly predictions. A reduction in MAPE of 5.27%, 11.45%, and 12.03% was achieved with PR, SVR and ANN, respectively. Full article

(This article belongs to the Topic Power System Modeling and Control)

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25 pages, 6699 KiB

Open AccessArticle

Evaluation Method for Winding Performance of Distribution Transformer

by Chunguang Suo, Yanan Ren, Wenbin Zhang, Yincheng Li, Yanyun Wang and Yi Ke

Energies 2021, 14(18), 5832; https://doi.org/10.3390/en14185832 - 15 Sep 2021

Cited by 1 | Viewed by 3008

Abstract

In order to ensure the safe and stable operation of a power system, the performance evaluation of transformer windings after a short-circuit test can predict whether the windings are deformed in order to provide a useful reference for the operation and maintenance of [...] Read more.

In order to ensure the safe and stable operation of a power system, the performance evaluation of transformer windings after a short-circuit test can predict whether the windings are deformed in order to provide a useful reference for the operation and maintenance of the power sector. This paper proposes a method for evaluating the performance of transformer windings in order to improve the overall effectiveness of a winding evaluation. The index data obtained based on a short-circuit impedance method, frequency response method, and oscillation wave method are used in the algorithm proposed in this paper. First, the transformer winding performance evaluation index system is constructed. Second, the weight of each index is determined by analytic hierarchy process, and then the fuzzy comprehensive assessment method is introduced, and the fuzzy evaluation matrix is established, the evaluation results are calculated using the evaluation formula. Finally, the maximum membership principle is used to determine the performance level of the transformer winding on the evaluation results, and the evaluation results of the transformer winding state are obtained. The example shows that the evaluation level of the measured transformer winding performance can be obtained by this method as “good”. Compared with the traditional method, this method can simplify the evaluation while maintaining higher accuracy. Full article

(This article belongs to the Topic Power System Modeling and Control)

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17 pages, 2310 KiB

Open AccessArticle

Analysis of Power Bank Quality Criteria That Are Important from the Consumer’s Point of View

by Jacek Czerniak, Anna Gacek and Przemysław Szopa

Energies 2021, 14(18), 5747; https://doi.org/10.3390/en14185747 - 13 Sep 2021

Cited by 3 | Viewed by 16342

Abstract

Consumers of mobile devices expect manufacturers to produce devices that will be an efficient source of electric energy. The batteries currently used in smartphones allow the devices to operate for several hours. Power banks extend the operating time of the device without the [...] Read more.

Consumers of mobile devices expect manufacturers to produce devices that will be an efficient source of electric energy. The batteries currently used in smartphones allow the devices to operate for several hours. Power banks extend the operating time of the device without the need to charge via a charger connected to the mains. The present paper defines first the features of power banks that are the most important for users and, moreover, what knowledge or opinions about important power bank features customers use during purchase. As shown in the survey, according to the respondents, the most important feature determining the quality of a power bank is its capacity. It has been shown in this research that the actual capacity of a power bank is circa 2/3 of the capacity indicated. What have also been investigated are the differences between the average capacities of power banks with Li-ion batteries and the technologically newer Li-Po batteries, in favor of the latter. Power banks were not differentiated according to the type of battery and charging times in the standard variant, with a voltage of 5 V. It has been shown that the smaller usable capacity of the power bank does not affect the faster charging time. Full article

(This article belongs to the Topic Power System Modeling and Control)

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20 pages, 8282 KiB

Open AccessArticle

Multi-Parameter Quadratic Programming Explicit Model Predictive Based Real Time Turboshaft Engine Control

by Nannan Gu, Xi Wang and Meiyin Zhu

Energies 2021, 14(17), 5539; https://doi.org/10.3390/en14175539 - 4 Sep 2021

Cited by 9 | Viewed by 2409

Abstract

The traditional model predictive control (tMPC) algorithms have a large amount of online calculation, which makes it difficult to apply them directly to turboshaft engine–rotor systems because of real time requirements. Therefore, based on the theory of the perturbed piecewise affine system (PWA) [...] Read more.

The traditional model predictive control (tMPC) algorithms have a large amount of online calculation, which makes it difficult to apply them directly to turboshaft engine–rotor systems because of real time requirements. Therefore, based on the theory of the perturbed piecewise affine system (PWA) and multi-parameter quadratic programming explicit model predictive control (mpQP-eMPC) algorithm, we develop a controller design method for turboshaft engine–rotor systems, which can be used for engine steady-state, transient state and limit protection control. This method consists of two steps: controller offline design and online implementation. Firstly, the parameter space of the PWA system is divided into several partitions offline based on the disturbance and performance constraints. Each partition has its own control law, which is in the form of piecewise affine linear function between the controller and the parameters. The control laws for those partitions are also obtained in this offline step. After which, for the online control implementation step, the corresponding control law can be obtained by a real-time query of a corresponding partition, which the current engine state falls into. This greatly reduces the amount of online calculation and thus improves the real-time performance of the MPC controller. The effectiveness of the proposed method is verified by simulating the steady-state and transient process of a turboshaft engine–rotor system with a limit protection requirement. Compared with tMPC, an mpQP-eMPC based controller can not only guarantee good steady-state, dynamic control performance and limit protection, but can also significantly improve the real-time performance of the control system. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 7890 KiB

Open AccessArticle

Real-Time Energy Management for DC Microgrids Using Artificial Intelligence

by Aiman J. Albarakati, Younes Boujoudar, Mohamed Azeroual, Reda Jabeur, Ayman Aljarbouh, Hassan El Moussaoui, Tijani Lamhamdi and Najat Ouaaline

Energies 2021, 14(17), 5307; https://doi.org/10.3390/en14175307 - 26 Aug 2021

Cited by 28 | Viewed by 5251

Abstract

Microgrids are defined as an interconnection of several renewable energy sources in order to provide the load power demand at any time. Due to the intermittence of renewable energy sources, storage systems are necessary, and they are generally used as a backup system. [...] Read more.

Microgrids are defined as an interconnection of several renewable energy sources in order to provide the load power demand at any time. Due to the intermittence of renewable energy sources, storage systems are necessary, and they are generally used as a backup system. Indeed, to manage the power flows along the entire microgrid, an energy management strategy (EMS) is necessary. This paper describes a microgrid energy management system, which is composed of solar panels and wind turbines as renewable sources, Li-ion batteries, electrical grids as backup sources, and AC/DC loads. The proposed EMS is based on the maximum extraction of energy from the renewable sources, by making them operate under Maximum Power Point Tracking (MPPT) mode; both of those MPPT algorithms are implemented with a multi-agent system (MAS). In addition, management of the stored energy is performed through the optimal control of battery charging and discharging using artificial neural network controllers (ANNCs). The main objective of this system is to maintain the power balance in the microgrid and to provide a configurable and a flexible control for the different scenarios of all kinds of variations. All the system’s components were modeled in MATLAB/Simulink, the MAS system was developed using Java Agent Development Framework (JADE), and Multi-Agent Control using Simulink with Jade extension (MACSIMJX) was used to insure the communication between Simulink and JADE. Full article

(This article belongs to the Topic Power System Modeling and Control)

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26 pages, 8934 KiB

Open AccessArticle

Transient Analysis of Multiphase Transmission Lines Located above Frequency-Dependent Soils

by Tainá Fernanda Garbelim Pascoalato, Anderson Ricardo Justo de Araújo, Pablo Torrez Caballero, Jaimis Sajid Leon Colqui and Sérgio Kurokawa

Energies 2021, 14(17), 5252; https://doi.org/10.3390/en14175252 - 25 Aug 2021

Cited by 7 | Viewed by 2579

Abstract

This paper evaluates the influence of frequency-dependent soil conductivity and permittivity in the transient responses of single- and double-circuit transmission lines including the ground wires subjected to lightning strikes. We use Nakagawa’s approach to compute the ground-return impedance and admittance matrices where the [...] Read more.

This paper evaluates the influence of frequency-dependent soil conductivity and permittivity in the transient responses of single- and double-circuit transmission lines including the ground wires subjected to lightning strikes. We use Nakagawa’s approach to compute the ground-return impedance and admittance matrices where the frequency-dependent soil is modeled using Alípio and Visacro’s model. We compare some elements of these matrices with those calculated by Carson’s approach which assumes the frequency constant. Results show that a significant difference can be obtained in high resistive soils for these elements in impedance and admittance matrices. Then, we compute the transient responses for single- and double-circuit lines with ground wires located above soils of 500, 1000, 5000, and 10,000 Ω·m considering the frequency constant and frequency-dependent parameters generated for two lightning strikes (subsequent stroke and Gaussian pulse). We demonstrate that the inclusion of frequency dependence of soil results in an expressive reduction of approximately 26.15% and 42.75% in the generated voltage peaks in single- and double-circuit lines located above a high-resistive soil. These results show the impact of the frequency-dependent soils that must be considered for a precise transient analysis in power systems. Full article

(This article belongs to the Topic Power System Modeling and Control)

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21 pages, 3306 KiB

Open AccessArticle

Bumpless Transfer of Uncertain Switched System and Its Application to Turbofan Engines

by Penghui Sun, Xi Wang, Shubo Yang, Bei Yang, Huairong Chen and Bin Wang

Energies 2021, 14(16), 5204; https://doi.org/10.3390/en14165204 - 23 Aug 2021

Cited by 4 | Viewed by 2260

Abstract

Nonlinear control problems in turbofan engines are challenging. No single nonlinear controller can achieve desired control effects in a full flight envelope, but in the case of multiple controllers, there exist problems in the bumpless transfer between different controllers. To this end, this [...] Read more.

Nonlinear control problems in turbofan engines are challenging. No single nonlinear controller can achieve desired control effects in a full flight envelope, but in the case of multiple controllers, there exist problems in the bumpless transfer between different controllers. To this end, this paper presents a bumpless transfer mechanism for an uncertain switched system based on integral sliding mode control (ISMC), and the mechanism can be used for the speed control of turbofan engines. The uncertain switched system is used to describe the turbofan engine dynamics. Then, the ISMC controller is derived for subsystems of the uncertain switched system. A resetting scheme is introduced for the ISMC controller to ensure the continuity of control inputs during the controller transition, as well as the bumpless transfer. In view of the transient behavior caused by controller switching, the global stability of the switched system is analyzed using the multiple Lyapunov function approach and average dwell time condition. Simulation results validate that the designed resetting scheme can ensure the continuity of control input signals and avoid the instability caused by high-frequency controller switching, and increase the control effectiveness of the proposed ISMC method within the full flight envelope. Full article

(This article belongs to the Topic Power System Modeling and Control)

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37 pages, 13580 KiB

Open AccessArticle

DYN3D and CTF Coupling within a Multiscale and Multiphysics Software Development (Part I)

by Sebastian Davies, Dzianis Litskevich, Ulrich Rohde, Anna Detkina, Bruno Merk, Paul Bryce, Andrew Levers and Venkata Ravindra

Energies 2021, 14(16), 5060; https://doi.org/10.3390/en14165060 - 17 Aug 2021

Cited by 3 | Viewed by 3411

Abstract

Understanding and optimizing the relation between nuclear reactor components or physical phenomena allows us to improve the economics and safety of nuclear reactors, deliver new nuclear reactor designs, and educate nuclear staff. Such relation in the case of the reactor core is described [...] Read more.

Understanding and optimizing the relation between nuclear reactor components or physical phenomena allows us to improve the economics and safety of nuclear reactors, deliver new nuclear reactor designs, and educate nuclear staff. Such relation in the case of the reactor core is described by coupled reactor physics as heat transfer depends on energy production while energy production depends on heat transfer with almost none of the available codes providing full coupled reactor physics at the fuel pin level. A Multiscale and Multiphysics nuclear software development between NURESIM and CASL for LWRs has been proposed for the UK. Improved coupled reactor physics at the fuel pin level can be simulated through coupling nodal codes such as DYN3D as well as subchannel codes such as CTF. In this journal article, the first part of the DYN3D and CTF coupling within the Multiscale and Multiphysics software development is presented to evaluate all inner iterations within one outer iteration to provide partially verified improved coupled reactor physics at the fuel pin level. Such verification has proven that the DYN3D and CTF coupling provides improved feedback distributions over the DYN3D coupling as crossflow and turbulent mixing are present in the former. Full article

(This article belongs to the Topic Power System Modeling and Control)

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13 pages, 1778 KiB

Open AccessArticle

Model Predictive Control with Modulator Applied to Grid Inverter under Voltage Distorted

by Angelo Lunardi, Eliomar R. Conde D, Jefferson de Assis, Darlan A. Fernandes and Alfeu J. Sguarezi Filho

Energies 2021, 14(16), 4953; https://doi.org/10.3390/en14164953 - 12 Aug 2021

Cited by 15 | Viewed by 2843

Abstract

This research paper presents a model of predictive control with a modulator for the inverter linked to the electrical grid, using the stationary reference frame and operating under grid distorted voltage. The stationary reference frame model for the system is obtained in its [...] Read more.

This research paper presents a model of predictive control with a modulator for the inverter linked to the electrical grid, using the stationary reference frame and operating under grid distorted voltage. The stationary reference frame model for the system is obtained in its fundamental frequency and then the model predictive technique is implemented, which predicts the system actions using the obtained system model without the need of any other harmonic consideration. The controller calculates the voltage vector of the inverter through the minimization of the cost function. Thus, the proposal demonstrates, through experiments, its positive results regarding the low impact of the distorted voltage in the grid current without using any harmonic consideration on the model. Experimental results and comparisons carried out endorse the proposal of this work. Full article

(This article belongs to the Topic Power System Modeling and Control)

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15 pages, 11144 KiB

Open AccessArticle

Steady-State Control of Fuel Cell Based on Boost Mode of a Dual Winding Motor

by Cheng Chang, Weibin Chang, Jiangang Ma and Yafu Zhou

Energies 2021, 14(15), 4673; https://doi.org/10.3390/en14154673 - 1 Aug 2021

Viewed by 1836

Abstract

In recent years, a dual winding motor drive has been proposed in the field of fuel cell vehicles due to its advantages of good performance and high robustness. This new topology and its basic control method have been widely investigated. However, the previous [...] Read more.

In recent years, a dual winding motor drive has been proposed in the field of fuel cell vehicles due to its advantages of good performance and high robustness. This new topology and its basic control method have been widely investigated. However, the previous research has not considered the current dynamic property of a fuel cell when studying the power sharing control method, but this is an important research objective for fuel cell durability. Considering the current change principle of a fuel cell, an optimal steady-state control method based on a new dual winding motor architecture boost charging is proposed to optimize the fuel cell life. In addition, in view of the current circulation problem of the fuel cell side winding in the boost mode, a Bang-Bang-PI control algorithm with a relatively constant reference value is proposed to realize the current sharing control. On this basis, the optimized control of the output current ripple of the fuel cell is realized to ensure the steady-state of the proton exchange membrane fuel cell (PEMFC). Finally, the results show that this method can control the stability of the fuel cell efficiently. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 12172 KiB

Open AccessArticle

A Robust Vector Current Controller with Negative-Sequence Current Capability for Grid-Connected Inverters

by Houshang Karimi, Aboutaleb Haddadi, Masoud Karimi-Ghartemani and Mahdieh Sadabadi

Energies 2021, 14(15), 4549; https://doi.org/10.3390/en14154549 - 27 Jul 2021

Cited by 5 | Viewed by 2309

Abstract

This paper presents a vector current controller (in the synchronous reference, or the dq, frame) with negative-sequence current injection capability for three-phase grid-connected converters. This capability is desired for the operation of the converter during unbalanced conditions and also for a certain type [...] Read more.

This paper presents a vector current controller (in the synchronous reference, or the dq, frame) with negative-sequence current injection capability for three-phase grid-connected converters. This capability is desired for the operation of the converter during unbalanced conditions and also for a certain type of islanding detection. The proposed controller first determines the double-frequency current references and then uses a sixth-order two-input two-output proportional-integral-resonance (PIR) structure, which is optimally designed. Compared with the existing similar approaches, the proposed controller has a simpler structure and more robust performance, e.g., against system parameter uncertainties and weak grid conditions. The proposed controller is developed for converters with both the L-type and

L C L

-type filters. For the

L C L

-type converter, a suboptimal partial state feedback control is also proposed to achieve robust stability and active damping of resonance poles without requiring additional sensors. Detailed experimental results are presented to illustrate the properties and performances of the proposed controller. Full article

(This article belongs to the Topic Power System Modeling and Control)

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17 pages, 1145 KiB

Open AccessArticle

Dynamic Low Voltage Ride through Detection and Mitigation in Brushless Doubly Fed Induction Generators

by Ahsanullah Memon, Mohd Wazir Mustafa, Muhammad Naveed Aman, Mukhtar Ullah, Tariq Kamal and Abdul Hafeez

Energies 2021, 14(15), 4461; https://doi.org/10.3390/en14154461 - 23 Jul 2021

Cited by 6 | Viewed by 1926

Abstract

Brushless doubly-fed induction generators have higher reliability, making them an attractive choice for not only offshore applications but also for remote locations. These machines are composed of two back-to-back voltage source converters: the grid side converter and the rotor side converter. The rotor [...] Read more.

Brushless doubly-fed induction generators have higher reliability, making them an attractive choice for not only offshore applications but also for remote locations. These machines are composed of two back-to-back voltage source converters: the grid side converter and the rotor side converter. The rotor side converter is typically used for reactive current control of the power winding using the control winding current. A low voltage ride through (LVRT) fault is detected using a hysterisis comparison of the power winding voltage. This approach leads to two problems, firstly, the use of only voltage to detect faults results in erroneous or slow response, and secondly, sub-optimal control of voltage drop because of static reference values for reactive current compensation. This paper solves these problems by using an analytical model of the voltage drop caused by a short circuit. Moreover, using a fuzzy logic controller, the proposed technique employs the voltage frequency in addition to the power winding voltage magnitude to detect LVRT conditions. The analytical model helps in reducing the power winding voltage drop while the fuzzy logic controller leads to better and faster detection of faults, leading to an overall faster response of the system. Simulations in Matlab/Simulink show that the proposed technique can reduce the voltage drop by up to 0.12 p.u. and result in significantly lower transients in the power winding voltage as compared to existing techniques. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 9148 KiB

Open AccessArticle

Arc Fault Detection Algorithm Based on Variational Mode Decomposition and Improved Multi-Scale Fuzzy Entropy

by Lina Wang, Hongcheng Qiu, Pu Yang and Longhua Mu

Energies 2021, 14(14), 4137; https://doi.org/10.3390/en14144137 - 8 Jul 2021

Cited by 18 | Viewed by 3024

Abstract

Arc fault diagnosis is necessary for the safety and efficiency of PV stations. This study proposed an arc fault diagnosis algorithm formed by combining variational mode decomposition (VMD), improved multi-scale fuzzy entropy (IMFE), and support vector machine (SVM). This method first uses VMD [...] Read more.

Arc fault diagnosis is necessary for the safety and efficiency of PV stations. This study proposed an arc fault diagnosis algorithm formed by combining variational mode decomposition (VMD), improved multi-scale fuzzy entropy (IMFE), and support vector machine (SVM). This method first uses VMD to decompose the current into intrinsic mode functions (IMFs) in the time-frequency domain, then calculates the IMFE according to the IMFs associated with the arc fault. Finally, it uses SVM to detect arc faults according to IMFEs. Arc fault data gathered from a PV arc generation experiment platform are used to validate the proposed method. The results indicated the proposed method can classify arc fault data and normal data effectively. Full article

(This article belongs to the Topic Power System Modeling and Control)

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20 pages, 2900 KiB

Open AccessArticle

Exhaustive Comparison between Linear and Nonlinear Approaches for Grid-Side Control of Wind Energy Conversion Systems

by Younes Azelhak, Loubna Benaaouinate, Hicham Medromi, Youssef Errami, Tarik Bouragba and Damien Voyer

Energies 2021, 14(13), 4049; https://doi.org/10.3390/en14134049 - 5 Jul 2021

Cited by 1 | Viewed by 2589

Abstract

In this paper, we propose a comparative study of linear and nonlinear algorithms designed for grid-side control of the power flow in a wind energy conversion system. We performed several simulations and experiments with step and variable power scenarios for different values of [...] Read more.

In this paper, we propose a comparative study of linear and nonlinear algorithms designed for grid-side control of the power flow in a wind energy conversion system. We performed several simulations and experiments with step and variable power scenarios for different values of the DC-link capacity with the DC storage element being the key element of the grid-side converter. The linear control was designed on the basis of the internal model control theory where an active damping was added to avoid steady state errors. Nonlinear controls were built using first and second order sliding mode controls with theoretical considerations to ensure accuracy and stability. We observed that the first order sliding mode control was the most efficient algorithm for controlling the DC-link voltage but that the chattering degraded the quality of the energy injected into the grid as well as the efficiency of the grid-side converter. The linear control caused overshoots on the DC-link voltage; however, this algorithm had better performance on the grid side due to its smoother control. Finally, the second order sliding mode control did not prove to be more robust than the other two algorithms. This can be explained by the fact that this control is theoretically more sensitive to converter losses. Full article

(This article belongs to the Topic Power System Modeling and Control)

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23 pages, 5027 KiB

Open AccessArticle

Field-Ready Implementation of Linear Economic Model Predictive Control for Microgrid Dispatch in Small and Medium Enterprises

by Tobias Kull, Bernd Zeilmann and Gerhard Fischerauer

Energies 2021, 14(13), 3921; https://doi.org/10.3390/en14133921 - 30 Jun 2021

Cited by 6 | Viewed by 3743

Abstract

The increasing share of distributed renewable energy resources (DER) in the grid entails a paradigm shift in energy system operation demanding more flexibility on the prosumer side. In this work we show an implementation of linear economic model predictive control (MPC) for flexible [...] Read more.

The increasing share of distributed renewable energy resources (DER) in the grid entails a paradigm shift in energy system operation demanding more flexibility on the prosumer side. In this work we show an implementation of linear economic model predictive control (MPC) for flexible microgrid dispatch based on time-variable electricity prices. We focus on small and medium enterprises (SME) where information and communications technology (ICT) is available on an industrial level. Our implementation uses field devices and is evaluated in a hardware-in-the-loop (HiL) test bench to achieve high technological maturity. We use available forecasting techniques for power demand and renewable energy generation and evaluate their influence on energy system operation compared to optimal operation under perfect knowledge of the future and compared to a status-quo operation strategy without control. The evaluation scenarios are based on an extensive electricity price analysis to increase representativeness of the simulation results and are based on the use of historic real-world measurements in an existing production facility. Due to real-world restrictions (imperfect forecast knowledge, implementation on field hardware, power fluctuations), between 72.2% and 85.5% of the economic optimum (rather than 100%) is reached. Together with reduced operation cost, the economic MPC implementation on field-typical industrial ICT leads to an increased share of renewable energy demand. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 10704 KiB

Open AccessArticle

Investigating the Shielding Effect of Pulse Transformer Operation in Isolated Gate Drivers for SiC MOSFETs

by Loreine Makki, Marc Anthony Mannah, Christophe Batard, Nicolas Ginot and Julien Weckbrodt

Energies 2021, 14(13), 3866; https://doi.org/10.3390/en14133866 - 27 Jun 2021

Cited by 2 | Viewed by 3414

Abstract

Wide-bandgap technology evolution compels the advancement of efficient pulse-width gate-driver devices. Integrated enhanced gate-driver planar transformers are a source of electromagnetic disturbances due to inter-winding capacitances, which serve as a route to common-mode (CM) currents. This paper will simulate, via ANSYS Q3D Extractor, [...] Read more.

Wide-bandgap technology evolution compels the advancement of efficient pulse-width gate-driver devices. Integrated enhanced gate-driver planar transformers are a source of electromagnetic disturbances due to inter-winding capacitances, which serve as a route to common-mode (CM) currents. This paper will simulate, via ANSYS Q3D Extractor, the unforeseen parasitic effects of a pulse planar transformer integrated in a SiC MOSFET gate-driver card. Moreover, the pulse transformer will be ameliorated by adding distinctive shielding layers aiming to suppress CM noise effects and endure high dv/dt occurrences intending to validate experimental tests. The correlation between stray capacitance and dv/dt immunity results after shielding insertion will be reported. Full article

(This article belongs to the Topic Power System Modeling and Control)

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14 pages, 6803 KiB

Open AccessArticle

Degradation-Conscious Equivalent Consumption Minimization Strategy for a Fuel Cell Hybrid System

by Laeun Kwon, Dae-Seung Cho and Changsun Ahn

Energies 2021, 14(13), 3810; https://doi.org/10.3390/en14133810 - 24 Jun 2021

Cited by 14 | Viewed by 2490

Abstract

The design of an energy management strategy is critical to improving the fuel efficiency of a vehicle system with an alternative powertrain system, such as hybrid electric vehicles or fuel cell electric vehicles. In particular, in fuel cell electric vehicles, the energy management [...] Read more.

The design of an energy management strategy is critical to improving the fuel efficiency of a vehicle system with an alternative powertrain system, such as hybrid electric vehicles or fuel cell electric vehicles. In particular, in fuel cell electric vehicles, the energy management strategy should consider system degradation and fuel savings because the hardware cost of the fuel cell system is much higher than that of a conventional powertrain system. In this paper, an easily implantable near-optimal energy management controller is proposed. The proposed controller distributes power generation between the fuel cell and the battery to simultaneously minimize system degradation and fuel usage. The controller is designed to consider the degradation cost and fuel cost in the framework of the equivalent consumption minimization strategy concept. The proposed controller was validated with a fuel cell electric vehicle model in MATLAB/Simulink (MathWorks, Natick, MA, USA). The proposed control strategy showed significant overall cost reduction compared to a thermostat control strategy and a conventional Equivalent Consumption Minimization Strategy (ECMS) strategy. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 2797 KiB

Open AccessArticle

Analytical Approach to Understanding the Effects of Implementing Fast-Frequency Response by Wind Turbines on the Short-Term Operation of Power Systems

by Danny Ochoa and Sergio Martinez

Energies 2021, 14(12), 3660; https://doi.org/10.3390/en14123660 - 19 Jun 2021

Cited by 11 | Viewed by 2421

Abstract

The significant presence of variable-speed wind turbines in worldwide power systems has led to planners and grid operators requiring them to participate in frequency control tasks. To address this demand, a large number of wind frequency control proposals have been reported in the [...] Read more.

The significant presence of variable-speed wind turbines in worldwide power systems has led to planners and grid operators requiring them to participate in frequency control tasks. To address this demand, a large number of wind frequency control proposals have been reported in the literature in recent years. Many of these solutions have been tested by specific experiments carried out in computer simulation environments. This paper proposes a methodology to evaluate the effects of enabling frequency support by wind turbines on the magnitudes that characterize the inertial response of a power system by using an analytical approach. The derived formulation and the illustrations are designed to provide a better understanding of both the mechanisms that determine the frequency stability indices and the improvement achieved by enabling the inertial response of wind turbines by implementing a virtual inertia-based method on the active power controllers of these machines. To facilitate the comprehension of the results obtained, the analytical approach is complemented with time-domain simulations in a predefined test system implemented in MATLAB/Simulink^®. The proposed methodology achieves a generalization of the results and can be used for the assessment of any power system configuration. Full article

(This article belongs to the Topic Power System Modeling and Control)

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18 pages, 1180 KiB

Open AccessReview

Distributed Learning Applications in Power Systems: A Review of Methods, Gaps, and Challenges

by Nastaran Gholizadeh and Petr Musilek

Energies 2021, 14(12), 3654; https://doi.org/10.3390/en14123654 - 19 Jun 2021

Cited by 12 | Viewed by 4787

Abstract

In recent years, machine learning methods have found numerous applications in power systems for load forecasting, voltage control, power quality monitoring, anomaly detection, etc. Distributed learning is a subfield of machine learning and a descendant of the multi-agent systems field. Distributed learning is [...] Read more.

In recent years, machine learning methods have found numerous applications in power systems for load forecasting, voltage control, power quality monitoring, anomaly detection, etc. Distributed learning is a subfield of machine learning and a descendant of the multi-agent systems field. Distributed learning is a collaboratively decentralized machine learning algorithm designed to handle large data sizes, solve complex learning problems, and increase privacy. Moreover, it can reduce the risk of a single point of failure compared to fully centralized approaches and lower the bandwidth and central storage requirements. This paper introduces three existing distributed learning frameworks and reviews the applications that have been proposed for them in power systems so far. It summarizes the methods, benefits, and challenges of distributed learning frameworks in power systems and identifies the gaps in the literature for future studies. Full article

(This article belongs to the Topic Power System Modeling and Control)

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16 pages, 444 KiB

Open AccessArticle

Implementation of Extended Kalman Filter with Optimized Execution Time for Sensorless Control of a PMSM Using ARM Cortex-M3 Microcontroller

by Justas Dilys, Voitech Stankevič and Krzysztof Łuksza

Energies 2021, 14(12), 3491; https://doi.org/10.3390/en14123491 - 12 Jun 2021

Cited by 26 | Viewed by 4383

Abstract

This paper addresses the implementation and optimization of an Extended Kalman Filter (EKF) for the Permanent Magnet Synchronous Motor (PMSM) sensorless control using an ARM Cortex-M3 microcontroller. A various optimization levels based on arithmetic calculation reduction was implemented in ARM Cortex-M3 microcontroller. The [...] Read more.

This paper addresses the implementation and optimization of an Extended Kalman Filter (EKF) for the Permanent Magnet Synchronous Motor (PMSM) sensorless control using an ARM Cortex-M3 microcontroller. A various optimization levels based on arithmetic calculation reduction was implemented in ARM Cortex-M3 microcontroller. The execution time of EKF estimator was reduced from 260.4 μs to 37.7 μs without loss of accuracy. To further reduce EKF execution time, the separation of a Kalman gain and covariance matrices calculation from prediction and measurement state update, a novel method was proposed, and the performance of it an EKF estimator with separation of a Kalman gain and covariance matrices calculation from prediction and measurement state update was analyzed. Simulation and experiments results validate that the proposed technique could provide the same accuracy with less computation time. A tendency of minimum Kalman gain and covariance matrices calculation frequency from rotor electrical frequency was analyzed and are presented in the paper. Full article

(This article belongs to the Topic Power System Modeling and Control)

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19 pages, 9825 KiB

Open AccessArticle

Analysis and Application of Two-Layer Unconventional Windings for PM-Assisted Synchronous Reluctance Motors

by Guohai Liu, Wenxuan Li, Qian Chen and Yanxin Mao

Energies 2021, 14(12), 3447; https://doi.org/10.3390/en14123447 - 10 Jun 2021

Cited by 1 | Viewed by 2730

Abstract

This paper presents a new winding configuration theory of conventional and unconventional slot-pole combinations that can be used to configure windings with any slot-pole combination. First, various two-layer windings can be divided into conventional balanced winding (CBW), unbalanced winding (UBW), unconventional even slot [...] Read more.

This paper presents a new winding configuration theory of conventional and unconventional slot-pole combinations that can be used to configure windings with any slot-pole combination. First, various two-layer windings can be divided into conventional balanced winding (CBW), unbalanced winding (UBW), unconventional even slot winding (UESW) and unconventional odd slot winding (UOSW). In addition, the winding configuration can be divided into two steps—slot sorting and slot distributions to phases—and the rule of winding distribution and connection of the four kinds of windings is given. Moreover, there are four models established corresponding to the four kinds of windings. The air-gap flux density and harmonic of models with double layer flux-barrier PM-assisted rotor and without flux-barrier rotor are analyzed and compared using two-dimensional transient finite element analysis (FEA). The effect of stator magneto motive force (MMF) on torque performance affected by winding configuration is analyzed by comparing air gap magnetic density under two kinds of rotors. The simulation of torque shows that UBW, UESW, and UOSW have a certain reducing effect on torque ripple in PMASynRM. Meanwhile, a brief comparison is made in terms of radial forces and power losses; the effects produced by UBW, UESW, and UOSW compared to CBW in these two aspects are acceptable. Full article

(This article belongs to the Topic Power System Modeling and Control)

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22 pages, 111815 KiB

Open AccessArticle

Impedance Modeling and Stability Analysis of DFIG-Based Wind Energy Conversion System Considering Frequency Coupling

by Shaojian Song, Peichen Guan, Bin Liu, Yimin Lu and Huihwang Goh

Energies 2021, 14(11), 3243; https://doi.org/10.3390/en14113243 - 1 Jun 2021

Cited by 13 | Viewed by 3109

Abstract

Impedance-based stability analysis is an effective method for addressing a new type of SSO accidents that have occurred in recent years, especially those caused by the control interaction between a DFIG and the power grid. However, the existing impedance modeling of DFIGs is [...] Read more.

Impedance-based stability analysis is an effective method for addressing a new type of SSO accidents that have occurred in recent years, especially those caused by the control interaction between a DFIG and the power grid. However, the existing impedance modeling of DFIGs is mostly focused on a single converter, such as the GSC or RSC, and the influence between the RSC and GSC, as well as the frequency coupling effect inside the converter are usually overlooked, reducing the accuracy of DFIG stability analysis. Hence, the entire impedance is proposed in this paper for the DFIG-based WECS, taking coupling factors into account (e.g., DC bus voltage dynamics, asymmetric current regulation in the dq frame, and PLL). Numerical calculations and HIL simulations on RT-Lab were used to validate the proposed model. The results indicate that the entire impedance model with frequency coupling is more accurate, and it is capable of accurately predicting the system’s possible resonance points. Full article

(This article belongs to the Topic Power System Modeling and Control)

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