基于LCL滤波的vienna拓扑三相整流技术研究

Research on the three phase rectifier technology of vienna topology based on the LCL filter

vienna拓扑整流器具有低开关损耗、三电平电压波形等优点,适于提高系统功率密度。为进一步提高功率密度,将LCL滤波器引入到三相vienna拓扑整流器前端,分析了不同电流反馈下,系统控制系统数字延时对系统稳定性的影响。基于vienna整流器相比普通三相整流器能工作于更高的开关频率的特点,提出利用DSP固有的数字控制的延时特性,在保持一定开关纹波衰减的情况下,合理设计LCL滤波器谐振频率,达到保持系统稳定和减小滤波器体积的目的。最后通过仿真和实验验证了理论推导和分析的合理性。

Vienna topology rectifier has the advantages of low switching losses as well as three-level voltage waveform which helps to improve the system power density. A LCL-filter-based three-phase vienna topology rectifier is introduced to further improve the system power density and an analysis is given about the effect of control system digital delay on the system stability under different current feedback. As the vienna topology rectifier can operate on higher switching frequencies compared to traditional three-phase rectifier, a method of designing the LCL filter resonance frequency is presented taking advantages of the DSP digital delay to maintain system stability and reduce the volume of the filter under a certain switching ripple attenuation. The experiments and simulations verify the theoretical derivation and analysis finally.