LCL滤波并网逆变器的鲁棒电流控制  

A Robust Current Control Strategy for Grid-connected Inverters with LCL Filters

作　　者：许津铭[1] 谢少军[1] 黄如海[1] 

机构地区：[1]南京航空航天大学自动化学院,江苏省南京市210016

出　　处：《电力系统自动化》2012年第19期99-104,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51077070);江苏省科技支撑计划资助项目(BE2010188)~~

摘　　要：采用LCL滤波器可以有效地滤除并网逆变器的开关频率次谐波,但是进网电流易产生谐振,闭环设计困难。加权平均的电流控制方案实现了降阶的系统闭环设计,较为简便,但是进网电流中存在依赖于非理想因素的欠阻尼共轭极点,影响谐振频率次谐波抑制效果,系统带宽受限。文中提出将有源阻尼控制同电流加权控制有机结合以克服上述问题。对比分析了电流加权控制、结合无源阻尼的电流加权控制及结合有源阻尼的电流加权控制的特性,对控制的鲁棒性进行了研究。研究表明,结合有源阻尼的电流加权控制可实现更优的鲁棒性,进一步改善了系统闭环控制特性,且设计简便。For grid-connected inverters,the switching frequency harmonics can be effectively attenuated through LCL filters,however,the grid current is easy to be resonated,which results in the difficulty in the system design.If the weighted average of the currents through two inductors is used for the feedback control,the high order control of LCL system is degraded to a low order one.In this way it is easy to obtain good system performance.However,there are still under-damped conjugate poles depending on the non-ideal factors in the grid current.The inhibitions of harmonics at the resonance frequencies are poor and the system bandwidth is limited.An idea of combining active damping and weighted current control together is proposed to overcome these difficulties.Besides,the control characteristics of the proposed method,including the robustness,are investigated and compared with those of the weighted current control with passive damping.The proposed control strategy can realize better robustness and further improve the system performance through a simple design procedure.

关 键 词：并网逆变器 滤波器 电流控制 有源阻尼 鲁棒性 

分 类 号：TM464[电气工程—电器]