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21 pages, 5330 KiB

Open AccessArticle

An Optimal Method of Energy Management for Regional Energy System with a Shared Energy Storage

by Xianan Jiao, Jiekang Wu, Yunshou Mao, Weiming Luo and Mengxuan Yan

Energies 2023, 16(2), 886; https://doi.org/10.3390/en16020886 - 12 Jan 2023

Cited by 4 | Viewed by 1312

Abstract

The regional energy system (RES) is a system that consumes multiple forms of energy in the region and achieves coordinated and efficient utilization of energy resources. The RES is composed of multiple micro energy systems (MESs); however, due to the mismatch of energy [...] Read more.

The regional energy system (RES) is a system that consumes multiple forms of energy in the region and achieves coordinated and efficient utilization of energy resources. The RES is composed of multiple micro energy systems (MESs); however, due to the mismatch of energy resources and different energy consumption within each MES, a large amount of clean energy is wasted, and each MES has to acquire extra energy. This significantly increases operation costs and contributes to environmental pollution. One of the promising ways to solve this problem is to deploy an energy storage system in the RES, which can make use of its advantages to transfer energy in space-time and fulfill the demand for loads in different periods, and conduct unified energy management for each MES in the RES. Nevertheless, a large number of users are deterred by the high investment in energy storage devices. A shared energy storage system (SESS) can allow multi-MESs to share one energy storage system, and meet the energy storage needs of different systems, to reduce the capital investment of energy storage systems and realize efficient consumption of clean energy. Taking multiple MESs as the object, this paper proposes a model and collaborative optimal strategy of energy management for the RES to accomplish high utilization of clean energy, environmental friendliness, and economy. First, the paper analyzes the internal energy supply characteristics of the RES and develops a model of the RES with an SESS. Then, the paper poses the management concept of load integration and unified energy distribution by using the operational information of each subsystem. An optimal operation strategy is established to minimize daily operation costs and achieve economic, environmentally friendly, and efficient operation of the RES. Third, by setting up scenarios such as no energy storage system and an independent energy storage system (IESS) of each MES and SESS, a case of a science and education park in Guangzhou, China, is illustrated for experiments. Numerical experiment results show that with an SESS built by the investor in the RES and applying the mentioned energy management strategy, the utilization of clean energy can be 100%, the operation costs can be reduced by up to 9.78%, the pollutant emission can be reduced by 3.92%, and the peak-to-valley difference can be decreased by 20.03%. Finally, the influence of energy storage service fees and electricity tariffs on daily operation costs is discussed, and the operation suggestions of the SESS are proposed. It validates the effectiveness of the proposed strategy. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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16 pages, 7552 KiB

Open AccessArticle

Sliding Mode Predictive Current Control for Single-Phase H-Bridge Converter with Parameter Robustness

by Wei Zheng, Zhaolong Sun and Baolong Liu

Energies 2023, 16(2), 781; https://doi.org/10.3390/en16020781 - 9 Jan 2023

Cited by 2 | Viewed by 1094

Abstract

As the important technology of renewable energy systems, power electronics technology is directly bound up with the prospect and development of renewable energy technology. As the output end of renewable energy systems, a single-phase H-bridge converter needs to stabilize the output current. When [...] Read more.

As the important technology of renewable energy systems, power electronics technology is directly bound up with the prospect and development of renewable energy technology. As the output end of renewable energy systems, a single-phase H-bridge converter needs to stabilize the output current. When predictive current control (PCC) tracks the reference current, the dynamic response is the fastest, but the control delay and the changes in model parameters will cause the output current steady-state error. The sliding mode predictive current control (SMPCC) algorithm is proposed to control the output current better. The proposed SMPCC scheme uses the combination of traditional PCC and variable structure scheme, and it establishes the mathematical model according to the state equation of the converter. Taking the exponential reaching law as control law, the expression of the variable structure controller is obtained. The MATLAB experimental and simulation results show that SMPCC can not only improve its robustness to the parameter changes but also obtain better steady-state performance while enhancing the rapidity of the current changes. In conclusion, SMPCC has a better control effect in the converter. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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11 pages, 4380 KiB

Open AccessArticle

Voltage Compensation and Energy Supplement-Based Power Conversion System and Its Experimental Verification

by Zhansheng Xi, Jianguo Li, Yufei Han, Yong Zhang and Haijun Wang

Energies 2022, 15(23), 8949; https://doi.org/10.3390/en15238949 - 26 Nov 2022

Viewed by 937

Abstract

A voltage compensation and energy supplement-based power conversion system (VC-PCS) is proposed in this paper. A VC-PCS is a series connected to a battery that only processes fractional battery power; therefore, it has lower rated voltage and power in comparison with traditional PCSs. [...] Read more.

A voltage compensation and energy supplement-based power conversion system (VC-PCS) is proposed in this paper. A VC-PCS is a series connected to a battery that only processes fractional battery power; therefore, it has lower rated voltage and power in comparison with traditional PCSs. Compared with results of previous studies, the VC-PCS proposed herein can output bipolar voltage to meet voltage variation requirements and is a necessary and comprehensive improvement to previous research. First, its topology structure, working principle, and control strategy are comprehensively examined in this paper. Next, results of the simulations and physical experiments carried out are presented; the results show that the proposed VC-PCS is feasible in principle, and can be realized in physical applications. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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12 pages, 3804 KiB

Open AccessArticle

Dynamic-State Analysis of Inverter Based on Cascode GaN HEMTs for PV Application

by Yajing Zhang, Jianguo Li, Jiuhe Wang, Trillion Q. Zheng and Pengyu Jia

Energies 2022, 15(20), 7791; https://doi.org/10.3390/en15207791 - 21 Oct 2022

Cited by 4 | Viewed by 1390

Abstract

With the increase in renewable energy generation, microgrid has put forward higher requirements on the power density and performance of the photovoltaic inverter. In this paper, the dynamic process of inverter based on the cascode Gallium nitride (GaN) high electron mobility transistor (HEMT) [...] Read more.

With the increase in renewable energy generation, microgrid has put forward higher requirements on the power density and performance of the photovoltaic inverter. In this paper, the dynamic process of inverter based on the cascode Gallium nitride (GaN) high electron mobility transistor (HEMT) for the photovoltaic (PV) application is analyzed in detail. The parasitic inductors and capacitors have been considered in our proposed equivalent model, which can explain the phenomenon that the crossover time of the voltage and current is prolonged by the parasitic parameters. The influence of the parasitic parameters is identified through theoretical analysis. By analyzing the influence of parasitic parameters, the design process of high-frequency inverter can be optimized. A 500 W inverter based on the cascode GaN HEMT is built, and the correctness of theoretical and simulation analysis is verified by the experimental results. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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13 pages, 4278 KiB

Open AccessArticle

Passivity-Based Control of Dual Active Bridge Converter in Constant Power Load Condition

by Jianguo Li, Yuming Zhao, Xuezhi Wu, Yajing Zhang and Jiuhe Wang

Energies 2022, 15(18), 6685; https://doi.org/10.3390/en15186685 - 13 Sep 2022

Viewed by 1213

Abstract

This paper presents a passivity-based control (PBC) based on the Euler–Lagrange (EL) model for dual active bridge (DAB) converters in the constant power load (CPL) condition. The EL model, which is derived from Kirchhoff’s current equations at the input and output nodes, is [...] Read more.

This paper presents a passivity-based control (PBC) based on the Euler–Lagrange (EL) model for dual active bridge (DAB) converters in the constant power load (CPL) condition. The EL model, which is derived from Kirchhoff’s current equations at the input and output nodes, is first presented in the DAB application, and the bidirectional CPL is considered in the theoretical analysis, simulation, and physical verification. The PBC has strong robustness to large-signal disturbance and negative incremental resistance load, and it is suitable for DAB converters in the CPL condition. In this paper, the DAB’s EL model, passivity analysis, stability analysis, and controller design are described in detail. The simulation results based on SIMULINK are also given in this paper. Finally, a DAB converter prototype is built to demonstrate the validity and feasibility of the proposed approach. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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14 pages, 3342 KiB

Open AccessArticle

DC-Link Voltage Stability Analysis of Grid-Tied Converters Using DC Impedance Models

by Ravi Kumar Gaddala, Mriganka Ghosh Majumder and Kaushik Rajashekara

Energies 2022, 15(17), 6247; https://doi.org/10.3390/en15176247 - 27 Aug 2022

Cited by 9 | Viewed by 1437

Abstract

With the integration of renewable energy sources into the power grid, a number of power electronic converters need to be connected together in parallel. Due to this interconnection among the power converters with a common DC bus, the equivalent impedance of the DC [...] Read more.

With the integration of renewable energy sources into the power grid, a number of power electronic converters need to be connected together in parallel. Due to this interconnection among the power converters with a common DC bus, the equivalent impedance of the DC network, i.e., DC network impedance (DCNI) of these parallel converters, may vary and can cause oscillations in the DC link voltage (DCLV). In the literature, impedance models of grid-tied converters (GCs) based on the AC side are well reported without including these variations in DCNI. In addition, the dynamics of a phase-locked loop (PLL) play a significant role in GC system stability. To evaluate these stability issues, this paper proposes small signal impedance models viewing from the DC side of a three-phase GC operating under different control modes considering the PLL dynamics and the DCNI variations. Using the proposed DC impedance models (DCIM), DCLV stability analysis is evaluated for a GC. It is verified through bode plots that the interaction between the proposed DCIM and DCNI leads to unstable operation of the closed-loop converter near the PLL bandwidth when the phase difference between DCIM and DCNI is more than 180 degrees. Finally, the analytically developed models are validated using hardware in-the-loop (HIL) testing. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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Review

Jump to: Research

30 pages, 4708 KiB

Open AccessReview

Review of Modeling, Modulation, and Control Strategies for the Dual-Active-Bridge DC/DC Converter

by Jiayang He, Yangyu Chen, Jiongtao Lin, Jianghui Chen, Li Cheng and Yu Wang

Energies 2023, 16(18), 6646; https://doi.org/10.3390/en16186646 - 15 Sep 2023

Cited by 3 | Viewed by 2314

Abstract

This paper provides a comprehensive review of the existing research on the Dual Active Bridge (DAB) DC-DC converter, focusing on modeling methods, modulation strategies, optimization algorithms, and control methods. A comparative analysis of selected methods along with guidelines to assist engineers and researchers [...] Read more.

This paper provides a comprehensive review of the existing research on the Dual Active Bridge (DAB) DC-DC converter, focusing on modeling methods, modulation strategies, optimization algorithms, and control methods. A comparative analysis of selected methods along with guidelines to assist engineers and researchers in their study of DAB is also presented. Firstly, a comprehensive review of modulation strategies for DAB is provided, ranging from classical phase-shift modulation to the popular asymmetric duty modulation. The intrinsic relationships among different modulation methods are summarized, and a comparison is made based on the difficulty of control and DAB operating characteristics. Secondly, the various modeling methods for DAB are described, including reduced-order modeling, generalized state-space averaging modeling, and discrete-time modeling methods. A comparison is made based on the suitability for different application scenarios, providing recommendations for the adoption of different modeling methods. Furthermore, a survey of optimization algorithms for modulation methods is presented, including classical algorithms, swarm intelligence optimization, and reinforcement learning algorithms. A number of criteria are proposed for different algorithms, and an analysis of the unresolved challenges and future prospects is provided. Finally, the advanced control methods for DAB are summarized based on control effectiveness and applicability. The article concludes with a summary and an outlook on future research directions is also provided. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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17 pages, 1736 KiB

Open AccessReview

Review on the Optimal Configuration of Distributed Energy Storage

by Ziqi Liu, Tingting Su, Zhiying Quan, Quanli Wu and Yu Wang

Energies 2023, 16(14), 5426; https://doi.org/10.3390/en16145426 - 17 Jul 2023

Cited by 2 | Viewed by 1943

Abstract

With the large-scale access of renewable energy, the randomness, fluctuation and intermittency of renewable energy have great influence on the stable operation of a power system. Energy storage is considered to be an important flexible resource to enhance the flexibility of the power [...] Read more.

With the large-scale access of renewable energy, the randomness, fluctuation and intermittency of renewable energy have great influence on the stable operation of a power system. Energy storage is considered to be an important flexible resource to enhance the flexibility of the power grid, absorb a high proportion of new energy and satisfy the dynamic balance between the supply and demand of a system. At present, the cost of energy storage is still high, and how to achieve the optimal energy storage configuration is the primary problem to be solved. Therefore, the current research progress in energy storage application scenarios, modeling method and optimal configuration strategies on the power generation side, grid side and user side are summarized in this paper. On this basis, the shortcomings that still exist of energy storage configuration research are summarized, and the future research direction for energy storage configuration is prospected. This review can provide reference for the latest development and future research and innovation direction for energy storage configuration. Full article

(This article belongs to the Special Issue Application Technology of Power Electronics in Renewable Energy Systems)

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