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18 pages, 7331 KiB

Open AccessArticle

Application and Comparison of a Modified Protection Scheme Utilizing a Proportional–Integral Controller with a Conventional Design to Enhance Doubly Fed Induction Generator Wind Farm Operations during a Balanced Voltage Dip

by Azeddine Loulijat, Hamid Chojaa, Mouncef El Marghichi, Naoufl Ettalabi, Abdelilah Hilali, Abdulwasa B. Barnawi, Z. M. S. Elbarbary and Mahmoud A. Mossa

Processes 2023, 11(10), 2834; https://doi.org/10.3390/pr11102834 - 26 Sep 2023

Cited by 2 | Viewed by 843

Abstract

The doubly fed induction generator (DFIG) is vulnerable to grid faults due to its direct stator connection, causing issues like excess stator current during voltage dips. Consequently, sensitive inverters suffer from increased currents, and the DC-link capacitor undergoes overcharging. This document examines two [...] Read more.

The doubly fed induction generator (DFIG) is vulnerable to grid faults due to its direct stator connection, causing issues like excess stator current during voltage dips. Consequently, sensitive inverters suffer from increased currents, and the DC-link capacitor undergoes overcharging. This document examines two protection strategies employing a proportional–integral (PI) controller to manage the transient rotor current and mitigate DC-link overcharging, thereby optimizing DFIG behavior during network faults. One option combines a classic crowbar circuit with a DC-chopper, while the other is a modified protection scheme (MPS) that includes an impedance with passive elements and a crowbar. The impedance forms a resistance R_p parallel with an inductance L_p. Both configurations, situated between the rotor coils and the rotor-side converter (RSC), augment the capacity for low-voltage ride-through (LVRT). MATLAB/SIMULINK simulations of the two schemes demonstrate successful rotor current reduction at 2.9 kA and 3.4 kA, and DC-link tension reduction below and at 1.4 KV. In addition, the conventional crowbar and MPS configurations efficiently restrict the RSC current to levels below 0.21 kA and 2.94 kA, while absorbing up to 2.52 kA and 1.52 kA, respectively. The key difference lies in the fact that fine-tuning the parameters in the MPS design prevents rotor disconnection when faced with a balanced fault. This enhancement enhances machine performance and enables full stator power control via the RSC. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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20 pages, 1050 KiB

Open AccessArticle

Stability Analysis: Two-Area Power System with Wind Power Integration

by Aldo Barrueto Guzmán, Héctor Chávez Oróstica and Karina A. Barbosa

Processes 2023, 11(8), 2488; https://doi.org/10.3390/pr11082488 - 18 Aug 2023

Viewed by 1089

Abstract

This paper focuses on a comprehensive stability study of a two-area power system with wind power integration and synthetic inertia control in each area, considering the effects of varying the interconnection link. Normally, synthetic inertia proposals are analyzed in one-area systems, in which [...] Read more.

This paper focuses on a comprehensive stability study of a two-area power system with wind power integration and synthetic inertia control in each area, considering the effects of varying the interconnection link. Normally, synthetic inertia proposals are analyzed in one-area systems, in which stability is tested without considering transmission system phenomena, such as coherency. As modern power systems are progressively becoming interconnected, the possibility of forming two or more non-coherent areas is likely, which poses a challenge to synthetic inertia control techniques that use system frequency as a main feedback signal. In this context, this work addresses a crucial gap in the existing literature and provides a valuable starting point for studying more complex interconnected power systems with wind power integration. Simulations were performed in Matlab-Simulink considering a data-driven frequency dynamics model of the Chilean Electric System, and a wind power model with synthetic inertia control

H_{2}

norm minimization in each area. The results showed that it is possible to find local optimal feedback gains, preserving the stability of the global system under significant variations in the interconnection link. RoCoF and Nadir indicators are provided, highlighting the benefits of synthetic inertia control, particularly in low-inertia situations. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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18 pages, 8331 KiB

Open AccessArticle

Research on an Adaptive Compound Control Strategy of a Hybrid Compensation System

by Hongxia Wang, Huilin Lei and Xiaoyuan Pei

Processes 2023, 11(7), 2109; https://doi.org/10.3390/pr11072109 - 14 Jul 2023

Cited by 2 | Viewed by 802

Abstract

This paper investigates the parallel harmonic resonance problem for hybrid compensation systems, consisting of active power filters and thyristor-switched capacitors, and proposes an adaptive composite control strategy for solving the parallel harmonic resonance problem that may arise in practical applications of hybrid compensation [...] Read more.

This paper investigates the parallel harmonic resonance problem for hybrid compensation systems, consisting of active power filters and thyristor-switched capacitors, and proposes an adaptive composite control strategy for solving the parallel harmonic resonance problem that may arise in practical applications of hybrid compensation systems. In practice, a hybrid compensation system can effectively solve harmonic and reactive power problems, but the equivalent reactance of the thyristor-switched capacitor and the supply line may form a parallel resonant circuit, which may generate parallel harmonic resonance when excited by a harmonic source at the non-linear load side, affecting the quality and stable operation of the system. The adaptive composite control strategy employs a second-order generalized integrator-frequency-locked loop (SOGI-FLL) to extract the harmonic voltage at the point of common coupling (PCC) and generate an adaptive damping current command using an adaptive algorithm, which adaptively adjusts the parameters of the resonance suppression controller through harmonic content limitation. Matlab/Simulink simulations show that the method effectively achieves harmonic resonance suppression of the power supply system under complex operating conditions, thus ensuring the stable operation and power quality of the power supply system. Therefore, the proposed control strategy is feasible and effective. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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16 pages, 2573 KiB

Open AccessArticle

Robust Cascade MRAC for a Hybrid Grid-Connected Renewable Energy System

by Juan Carlos Travieso-Torres, Abdiel Ricaldi-Morales, Adolfo Véliz-Tejo and Felipe Leiva-Silva

Processes 2023, 11(6), 1774; https://doi.org/10.3390/pr11061774 - 10 Jun 2023

Cited by 6 | Viewed by 957

Abstract

Hybrid grid-connected renewable energy systems have gained significant importance in sustainably responding to an increased electrical energy demand. These are time-varying nonlinear dynamical plants, where the value of their parameters depends on changing weather conditions and the alternating grid voltage with randomly fluctuating [...] Read more.

Hybrid grid-connected renewable energy systems have gained significant importance in sustainably responding to an increased electrical energy demand. These are time-varying nonlinear dynamical plants, where the value of their parameters depends on changing weather conditions and the alternating grid voltage with randomly fluctuating amplitude. This paper proposes a robust cascade MRAC for nonlinear plants representing a class of these systems, which includes n renewable energy converts and a DC/AC single-phase full bridge inverter. The proposal reduces commissioning time by avoiding linearization and knowledge of the plant parameters. Moreover, it includes specific formulas for tuning the controller parameters that decrease their adjustments based on trial and error. Finally, it uses a direct adaptive method with adaptive laws having

σ θ

modification and an inner loop at least five times faster than the outer loop. The proposition validation includes the theoretical stability proof based on the Lyapunov stability method and Barbalat’s Lemma. Furthermore, it presents comparative simulation results with quoted cascade PI controllers for a monophasic system, including two renewable energy sources and injection. Both techniques effectively track setpoint changes of the energy sources’ currents and direct current bus voltage, showing the proposal similar or reduced ripple. At the same time, both ensure robustness against decreased photovoltage panels irradiance, increased fuel cells voltage, and grid voltage amplitude random fluctuations. However, the proposal does these things while avoiding prior linearization and unknowing the plant parameters. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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14 pages, 565 KiB

Open AccessArticle

Economic Analysis: Green Hydrogen Production Systems

by María Teresa Muñoz Díaz, Héctor Chávez Oróstica and Javiera Guajardo

Processes 2023, 11(5), 1390; https://doi.org/10.3390/pr11051390 - 4 May 2023

Cited by 9 | Viewed by 4357

Abstract

The continued use of energy sources based on fossil fuels has various repercussions for the environment. These repercussions are being minimized through the use of renewable energy supplies and new techniques to decarbonize the global energy matrix. For many years, hydrogen has been [...] Read more.

The continued use of energy sources based on fossil fuels has various repercussions for the environment. These repercussions are being minimized through the use of renewable energy supplies and new techniques to decarbonize the global energy matrix. For many years, hydrogen has been one of the most used gases in all kinds of industry, and now it is possible to produce it efficiently, on a large scale, and in a non-polluting way. This gas is mainly used in the chemical industry and in the oil refining industry, but the constant growth of its applications has generated the interest of all the countries of the world. Its use in transportation, petrochemical industries, heating equipment, etc., will result in a decrease in the production of greenhouse gases, which are harmful to the environment. This means hydrogen is widely used and needed by countries, creating great opportunities for hydrogen export business. This paper details concepts about the production of green hydrogen, its associated technologies, and demand projections. In addition, the current situation of several countries regarding the use of this new fuel, their national strategy, and advances in research carried out in different parts of the world for various hydrogen generation projects are discussed. Additionally, the great opportunities that Chile has for this new hydrogen export business, thanks to the renewable energy production capacities in the north and south of the country, are discussed. The latter is key for countries that require large amounts of hydrogen to meet the demand from various industrial, energy, and transportation sectors. Therefore, it is of global importance to determine the real capacities that this country has in the face of this new green fuel. For this, modeling was carried out through mathematical representations, showing the behavior of the technologies involved in the production of hydrogen for a system composed of an on-grid photovoltaic plant, an electrolyser, and compressor, together with a storage system. The program optimized the capacities of the equipment in such a way as to reduce the costs of hydrogen production and thereby demonstrate Chile’s capacity for the production of this fuel. From this, it was found that the LCOH for the case study was equivalent to 3.5 USD/kg, which is not yet considered a profitable value for the long term. Due to this, five case studies were analyzed, to see what factors influence the LCOH, and thereby reduce it as much as possible. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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Review

Jump to: Research

23 pages, 2945 KiB

Open AccessReview

Active Power-Decoupling Methods for Photovoltaic-Connected Applications: An Overview

by Omar Rodríguez-Benítez, Mario Ponce-Silva, Juan Antonio Aqui-Tapia, Óscar Miguel Rodríguez-Benítez, Ricardo Eliú Lozoya-Ponce and Heriberto Adamas-Pérez

Processes 2023, 11(6), 1808; https://doi.org/10.3390/pr11061808 - 14 Jun 2023

Cited by 3 | Viewed by 1480

Abstract

This study compares ripple port, stacked switched capacitor, and capacitive energy storage architectures for active power decoupling, comparing the number of components, performance, energy density, DC-link capacitor reduction, efficiency, and frequency operation to highlight their main benefits and drawbacks for single-phase grid-connected applications. [...] Read more.

This study compares ripple port, stacked switched capacitor, and capacitive energy storage architectures for active power decoupling, comparing the number of components, performance, energy density, DC-link capacitor reduction, efficiency, and frequency operation to highlight their main benefits and drawbacks for single-phase grid-connected applications. The overview reveals equivalent effective energy density without electrolytic capacitors, as well as enhanced simplicity, performance, and durability, thereby providing stacked switched capacitors as an attractive power-decoupling alternative for multi-stage connected applications, based on the principle that its individual buffer capacitors absorb and deliver energy without tightly constraining their individual terminal voltages, while maintaining a narrow range voltage at the buffer DC port. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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30 pages, 7079 KiB

Open AccessReview

A Review on the Use of Active Power Filter for Grid-Connected Renewable Energy Conversion Systems

by Dipak Kumar Dash and Pradip Kumar Sadhu

Processes 2023, 11(5), 1467; https://doi.org/10.3390/pr11051467 - 12 May 2023

Cited by 6 | Viewed by 3221

Abstract

Renewable energy sources such as photovoltaic (PV) and wind energies are integrated into the grid due to their low global emissions and higher power conversion efficiency techniques. Grid-connected inverters are the core components of distributed generation networks. However, several harmonic current and voltage [...] Read more.

Renewable energy sources such as photovoltaic (PV) and wind energies are integrated into the grid due to their low global emissions and higher power conversion efficiency techniques. Grid-connected inverters are the core components of distributed generation networks. However, several harmonic current and voltage variations affect the performance of circuits in grid-connected networks. These issues can be easily resolved using passive filters, static vector generators, and dynamic energy filters (APFs). In higher-level units, the cost, dimensions, and weight of passive filters increase proportionally. The purpose of this research is to evaluate advanced APFs for reducing power switches and grid-connected weight, cost, and scale. Several studied APF inverter topologies, including single-phase, three-phase AC–AC, back-to-back, and common parameters, have been considered. Cost-effective solutions such as PV-based transformers based on APF, fewer inverters, multiple and multifunctional inverters, and wind-assisted conversion systems have been studied. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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21 pages, 4119 KiB

Open AccessReview

Toward to Hydrogen Energy of Electric Power: Characteristics and Main Case Studies in Shenzhen

by Zhijun Deng, Jinqiao Du, Jie Tian, Zhenning Gan, Bingjie Wang and Chen Zhao

Processes 2023, 11(3), 728; https://doi.org/10.3390/pr11030728 - 28 Feb 2023

Cited by 1 | Viewed by 2242

Abstract

China has pledged that it will strive to achieve peak carbon emission by 2030 and realize carbon neutrality by 2060, which has spurred renewed interest in hydrogen for widespread decarbonization of the economy. Hydrogen energy is an important secondary clean energy with the [...] Read more.

China has pledged that it will strive to achieve peak carbon emission by 2030 and realize carbon neutrality by 2060, which has spurred renewed interest in hydrogen for widespread decarbonization of the economy. Hydrogen energy is an important secondary clean energy with the advantage of high density, high calorific value, rich reserves, extensive sources and high conversion efficiency that can be widely used in power generation, transportation, fuel and other fields. In recent years, with the guidance of policies and the progress of technology, China’s hydrogen energy industry has developed rapidly. About 42% of China’s carbon emissions comes from the power system and Shenzhen has the largest urban power grid in China. Bringing the utilization of hydrogen energy into Shenzhen’s power system is an important method to achieve industry transformation, achieve the “double carbon” goal and promote sustainable development. This paper outlines the domestic and international development status of hydrogen energy, introduces the characteristics of Shenzhen new power system, the industrial utilization of hydrogen energy and the challenges of further integrating hydrogen energy into Shenzhen new power system and, finally, suggests on the integration of hydrogen energy into Shenzhen new power system in different dimensions. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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24 pages, 1166 KiB

Open AccessFeature PaperReview

A Review of Generators and Power Converters for Multi-MW Wind Energy Conversion Systems

by Saravanakumar Rajendran, Matias Diaz, Roberto Cárdenas, Enrique Espina, Emilio Contreras and Jose Rodriguez

Processes 2022, 10(11), 2302; https://doi.org/10.3390/pr10112302 - 5 Nov 2022

Cited by 14 | Viewed by 4993

Abstract

The rated power of wind turbines has consistently enlarged as large installations can reduce energy production costs. Multi-megawatt wind turbines are frequently used in offshore and onshore facilities, and today is possible to find wind turbines rated over 15 MW. New developments in [...] Read more.

The rated power of wind turbines has consistently enlarged as large installations can reduce energy production costs. Multi-megawatt wind turbines are frequently used in offshore and onshore facilities, and today is possible to find wind turbines rated over 15 MW. New developments in generators and power converters for multi-MW wind turbines are needed, as the trend toward upscaling the dimensions of wind turbines is expected to continue. Therefore, this paper provides a detailed review of commercially available and recently proposed multi-MW wind turbine generators and power converters. Furthermore, comparative analyses indicate the advantages and disadvantages of commercially available and promising technologies for generators and power converters at the multi-MW target. Full article

(This article belongs to the Special Issue Power Electronics for Energy Transition and Renewable Energy Conversion Processes)

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