T型三电平逆变器LCL滤波器设计

T-type Three-level Inverter LCL Filter Design

三相三电平逆变器在高压大功率领域的应用越来越广泛,主要得益于其dv/dt小、输出电压谐波小、EMI小等优点。而逆变器交流侧LCL滤波器的参数设计直接影响到逆变输出的滤波效果,并且关系到系统的尺寸和成本。本文在T型三电平逆变器的基础上,给出了一种LCL滤波器的参数设计方法。该设计方法结合逆变器的参数特点,确定了电感和电容的计算方法,并且给出了滤波器谐振频率的验证方法,最后以50kW并网逆变器为例进行了设计验证,结果证明了理论分析的正确性。

The application of three-phase three-level inverter in the field of high voltage and high power is more and more extensive,mainly due to its small dv/dt,small output voltage harmonics and small EMI.The parameter design of the AC side LCL filter of the inverter directly affects the filtering effect of the inverter output,and is related to the size and cost of the system.Based on the T-type three-level inverter,this paper presents a parameter design method for LCL filter.The design method combines the parameters of the inverter to determine the calculation method of the inductor and capacitor,and gives the verification method of the resonant frequency of the filter.Finally,the 50 kW grid-connected inverter is used as an example to verify the design.The result proves The correctness of theoretical analysis.