弱电网下单相LCL并网逆变器改进电流控制策略  

Improved Current Control Strategy for Single-phase LCL Grid-connected Inverter under Weak Grid

作　　者：李玉东[1,2] 侯岩 李佩峰 段乾超 王晓卫 LI Yudong;HOU Yan;LI Peifeng;DUAN Qianchao;WANG Xiaowei(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454003;Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment,Henan Polytechnic University,Jiaozuo 454003;School of Electrical Engineering,Xi’an University of Technology,Xi’an 710048)

机构地区：[1]河南理工大学电气工程与自动化学院,焦作454003 [2]河南理工大学河南省煤矿装备智能检测与控制重点实验室,焦作454003 [3]西安理工大学电气工程学院,西安710048

出　　处：《电气工程学报》2025年第1期119-130,共12页Journal of Electrical Engineering

基　　金：国家自然科学基金(61703144);河南省自然科学基金(182300410480)资助项目。

摘　　要：针对弱电网下电网阻抗宽范围变化降低并网逆变器系统稳定性、电网背景谐波导致并网电流波形畸变以及电压前馈自校正滤波产生正向谐振尖峰的问题,提出一种电压前馈自校正滤波结合逆变器系统并联自适应虚拟阻抗的控制策略。首先建立单相LCL型并网逆变器模型,分析电网阻抗对逆变器系统的影响,通过电压前馈自校正滤波提升逆变器系统的相位裕度,然后采用逆变器并联自适应虚拟阻抗的控制策略,削弱电压前馈自校正滤波产生的正向谐振尖峰,进一步提升逆变器系统的相位裕度,保证逆变器系统具有较好的动稳态性能,降低电网背景谐波对并网电流的影响,提升逆变器系统对弱电网的适应性。最后在Matlab/Simulink中建立仿真模型并搭建DSP电能变换试验平台,验证所提控制策略的有效性与实用性。Aiming at the problems that the wide range variation of grid impedance under weak grid reduces the stability of grid-connected inverter system,the grid-connected current waveform distortion caused by grid background harmonics and the positive resonance peak generated by voltage feed-forward self-tuning filter,a control strategy of voltage feed-forward self-tuning filter combined with parallel adaptive virtual impedance of inverter system is proposed.Firstly,a single-phase LCL-type grid-connected inverter model is established,and the influence of grid impedance on the inverter system is analyzed.The phase margin of the inverter system is improved by the voltage feed-forward self-tuning filter.Then,the control strategy of the inverter parallel adaptive virtual impedance is adopted to weaken the positive resonance peak generated by the voltage feed-forward self-tuning filter,further improve the phase margin of the inverter system,ensure that the inverter system has better dynamic and steady-state performance,reduce the influence of the grid background harmonics on the grid-connected current,and improve the adaptability of the inverter system to the weak grid.Finally,a simulation model is established in Matlab/Simulink and a DSP power conversion test platform is built to verify the effectiveness and practicability of the proposed control strategy.

关 键 词：弱电网 电网阻抗 电网背景谐波 自校正滤波 自适应虚拟阻抗 系统相位裕度 

分 类 号：TM464[电气工程—电器]