高性能光伏逆变器中LCL滤波器的设计与控制方法  

Design and Control Method of LCL Filter in High Performance Photovoltaic Inverter

作　　者：吴恒 刘馨宜 卢德龙 沈杰 WU Heng;LIU Xinyi;LU Delong;SHEN Jie(Suzhou Power Supply Company,State Grid Jiangsu Electric Power Co.,Ltd.,Suzhou 215004,Jiangsu,China)

机构地区：[1]国网江苏省电力有限公司苏州供电分公司,江苏苏州215004

出　　处：《电力大数据》2024年第12期1-10,共10页Power Systems and Big Data

基　　金：国家自然科学基金项目(51707014)。

摘　　要：与传统的L型和LC型滤波器相比,光伏逆变器中的LCL型滤波器在电感相同时对注入电网的高次谐波具有更好的抑制能力,谐波衰减非常明显。然而,使用LCL型滤波器很容易产生谐振峰,影响整个系统的稳定性。针对此问题,该文提出了一种高性能光伏逆变器中LCL滤波器的设计与控制方法,基于加权电流反馈的滞环电流控制,解决当前大规模光伏接入引发的终端配电网电能质量问题。滤波器分为主电路、LCL滤波器、控制系统、三相锁相环和仿真五部分。仿真实验结果表明:并网电流总谐波畸变率THD为3.06%,符合行业标准THD小于5%的要求;并网电流峰值为107.4 A,能够满足预设要求。因此,所提方法有效地抑制了LCL滤波器的谐振问题,提高了光伏并网电压和电流的控制能力。Compared with traditional L-type and LC type filters,the LCL type filter of photovoltaic inverters has better suppression ability for high-order harmonics injected into the grid under the same inductance,and the harmonic attenuation is very obvious.However,using LCL type filters can easily generate resonance peaks,affecting the stability of the entire system.In view of this,this paper proposes a design scheme for a photovoltaic grid connected inverter based on LCL filters.The scheme analyzes the direct torque control strategy of the photovoltaic grid connected inverter.Simulation tests show that the inverter effectively suppresses the resonance problem of LCL filters and improves the control ability of photovoltaic grid connected voltage and current.This design is divided into five parts:main circuit,LCL filter,control system,three-phase phase-locked loop,and simulation.The simulation results show that the total harmonic distortion rate(THD)of the grid connected current is 3.06%,which meets the industry standard of THD<5%.The peak grid connected current is 107.4 A,which can meet the preset requirements.The results indicate that the proposed method effectively suppresses the resonance problem of LCL filters and improves the control capability of photovoltaic grid connected voltage and current.

关 键 词：光伏逆变器 LCL滤波 解耦控制 锁相环 

分 类 号：TM464[电气工程—电器]