引用本文: | 王 祺,赵兴勇,张庚午.多功能并网变换器容量优化控制策略[J].电力系统保护与控制,2022,50(3):85-92.[点击复制] |
WANG Qi,ZHAO Xingyong,ZHANG Gengwu.Capacity optimization control strategy of a multi-function grid-connected converter[J].Power System Protection and Control,2022,50(3):85-92[点击复制] |
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摘要: |
随着“双高”电力系统的发展,并网环境呈现薄弱、复杂态势。电网阻抗的存在使得并网点容易受谐波干扰及无功功率波动的影响,恶化并网电能质量,影响并网变换器友好并网,仅以有功功率为传输目标的传统并网变换器已难以适应上述工况。基于现状提出一种具有谐波抑制功能的光伏逆变器控制策略。指令电流由谐波检测环节和直流侧稳压控制环节组成,根据广义瞬时无功理论检测出并网电流的瞬时有功分量、基波正序无功分量、谐波分量,通过电流跟踪控制环节实现光伏逆变器的抑制谐波、无功补偿的功能。随后,考虑实况中逆变器容量有限,提出一种基于复合功能光伏逆变器的容量匹配策略,设计匹配系数。考虑并网变换器的外特性及实际工况中的谐波特性,以输出有功功率、谐波抑制控制效果为最优控制级,无功补偿控制效果为次优级进行策略的设计。最后,进行仿真案例验证当光伏逆变器在正常并网运行时可以抑制并网点谐波电流,并最大程度的补偿无功功率,极大改善了并网点的电能质量,提高了逆变器的利用率,增强了并网变换器面向复杂并网工况时的鲁棒性。仿真结果验证了所提策略的有效性和可行性。 |
关键词: 光伏逆变器 控制策略 谐波抑制 无功补偿 容量匹配 |
DOI:DOI: 10.19783/j.cnki.pspc.210434 |
投稿时间:2021-04-19修订日期:2021-08-25 |
基金项目:山西省高等学校科技创新项目资助(2021L005);山西省应用基础研究计划青年项目资助(20210302124553) |
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Capacity optimization control strategy of a multi-function grid-connected converter |
WANG Qi,ZHAO Xingyong,ZHANG Gengwu |
(1. Shanxi University, Taiyuan 030006, China; 2. Taiyuan University of Technology, Taiyuan 030024, China) |
Abstract: |
With the development of the "double high" power system, the grid-connected environment is showing a weak and complex situation. The existence of grid impedance makes the grid-connected point susceptible to harmonic interference and reactive power fluctuations, deteriorates the quality of grid-connected power, and affects the friendly grid-connected converters. Traditional grid-connected converters that only use active power as the transmission target are already difficult to adapt to the above working conditions. Based on the status quo, a photovoltaic inverter control strategy with harmonic suppression function is proposed. The command current is composed of the harmonic detection link and the DC side voltage stabilization control link. According to the generalized instantaneous reactive power theory, the instantaneous active component, fundamental positive sequence reactive component, and harmonic component of the grid-connected current are detected, and the functions of suppressing harmonics and reactive power compensation of photovoltaic inverter are realized through the current tracking control link. Then, considering the limited capacity of the inverter in the actual situation, a capacity matching strategy based on the composite function photovoltaic inverter is proposed, and a matching coefficient is designed. Considering the external characteristics of the grid-connected converter and the harmonic characteristics in actual working conditions, a strategy is designed with the output active power and the harmonic suppression control effect as the optimal control level, and the reactive power compensation control effect as the sub-optimal level. Finally, a simulation case is carried out to verify that when the photovoltaic inverter is in normal grid-connected operation, it can suppress the harmonic current of the grid-connected point and compensate for the reactive power to the greatest extent. This greatly improves the power quality of the grid-connected point and improves the inverter. The utilization rate of the converter enhances the robustness of the grid-connected converter when facing complex grid-connected conditions. The simulation results verify the effectiveness and feasibility of the proposed strategy.
This work is supported by Shanxi Province Higher Education Science and Technology Innovation Project (No. 2021L005). |
Key words: photovoltaic inverter control strategy harmonic suppression reactive power compensation capacity matching |