逆变器单元用LCL滤波器的并联系统性能分析  

Performance analysis of parallel system using LCL filter inverter unit

作　　者：阚加荣[1] 谢少军[2] 刘爱忠[3] 

机构地区：[1]盐城工学院电气工程学院,江苏盐城224051 [2]南京航空航天大学自动化学院,江苏南京210016 [3]艾默生网络能源雅达电源科技有限公司,江苏南京210013

出　　处：《电机与控制学报》2010年第2期90-98,共9页Electric Machines and Control

摘　　要：由于各并联单元之间的参数差异,逆变器并联系统存在环流,其中的高频环流由于其频率超出系统的控制带宽,难以通过控制的方式进行抑制。本文分析了高频环流存在的原因,提出将并联逆变单元的LC滤波器改变为LCL滤波器。比较了LC滤波器和LCL滤波器的阻抗特性,分析了采用LC滤波器和LCL滤波器的逆变器的闭环输出特性,指出经过适当的参数设计可以使得这二种逆变器的等效输出阻抗在低频段相近而在高频段呈现很大差异。并联系统在采用了LCL滤波器的逆变器作为并联单元后,可以利用其高频高输出阻抗很好地抑制高频环流,同时可以保持较硬的输出电压外特性。仿真和实验都验证了该方法的有效性。Parallel inverter system has high frequency harmonic loop current because of parameters difference between parallel units. It is difficult to restrain the high frequency circulating current using control methods because the bandwidth of system is lower than the frequency of circulating current. The causation of high frequency circulating current is analyzed and proposed using LCL filter substitute the LC filter. The difference of impedance characteristic between LC filter and LCL filter are compared and the closed loop output characteristics of two types of inverters are analyzed. The equivalent output impedances of two types of inverters are approximately equal to each other in low frequency and show great difference in high frequency by designing properly. The parallel system keeps rigid output characteristic and dinky high frequency loop current by using the inverter with LCL filter as parallel unit. The simulation and experimdntal results show the validity of the proposed method.

关 键 词：逆变器 并联 LCL滤波器 高频环流 输出阻抗 

分 类 号：TM464[电气工程—电器]