非理想电网下逆变器并网电流质量改善策略  

Improvement strategy for grid-connected current quality of an inverter under non-ideal grid conditions

作　　者：杨龙月 郭锐 张乐 刘建华 郭向向 YANG Longyue;GUO Rui;ZHANG Le;LIU Jianhua;GUO Xiangxiang(School of Electrical and Power Engineering,China University of Mining and Technology,Xuzhou 221008,China;Maintenance Branch,State Grid Zhejiang Electric Power Co.,Ltd.,Hangzhou 311200,China;School of Pan-Asian Business,Yunnan Normal University,Kunming 650000,China)

机构地区：[1]中国矿业大学电气与动力工程学院,江苏徐州221008 [2]国网浙江省电力有限公司检修分公司,浙江杭州311200 [3]云南师范大学泛亚商学院,云南昆明650000

出　　处：《电力系统保护与控制》2020年第15期10-18,共9页Power System Protection and Control

基　　金：国家自然科学基金青年科学基金项目资助(51607179)。

摘　　要：逆变器在非理想的电网条件下采用传统的电网电压前馈控制时,其输出阻抗的相位裕度很低,且不能很好地抑制电网电压的谐波传入控制系统,从而很难保证其并网电流的质量。提出了一种改善在非理想电网条件下逆变器并网电流质量的方法。首先,建立PR控制下采用传统电网电压前馈的LCL型逆变器输出阻抗模型,提出利用带通滤波器改进的电网电压前馈策略,提高逆变器对电网阻抗的鲁棒性。同时在PR控制器上并联多次谐波补偿器,使其不仅能够提高逆变器对电网阻抗的鲁棒性而且能够有效地抑制电网电压谐波对逆变器并网电流的干扰,从而改善非理想电网条件下的逆变器并网电流的质量。最后,利用仿真和实验验证了所提方法的有效性。The phase margin of the output impedance is very low when the traditional grid voltage feed-forward control is used in an inverter under a non-ideal grid, and it cannot suppress the interference of the grid-voltage’s harmonic to the output current of the inverter well. Therefore it is difficult to guarantee the quality of grid-connected current. This paper presents a control strategy to improve the grid-connected current quality of inverters under non-ideal grid conditions. First, the output impedance model of LCL inverters with traditional grid voltage feed-forward under a PR controller is established, and an improved grid voltage feed-forward strategy based on a band-pass filter is proposed to improve the robustness of inverters to grid impedance. At the same time, a multi-harmonic compensator is connected in parallel with the PR controller. It can not only improve the robustness of the inverters to the impedance of the power grid, but also effectively restrain the interference of the harmonic voltage to the grid-connected current. Therefore, the quality of grid-connected current under the non-ideal grid can be improved. Finally, the effectiveness of the proposed method is verified by simulation and experiment.

关 键 词：电网电压前馈 逆变器输出阻抗 带通滤波器 多次谐波补偿器 并网电流质量 

分 类 号：TM464[电气工程—电器]