输入不平衡时双级矩阵变换器调制策略的改进

Improvement of Modulation Strategy of Two Stage Matrix Converter under Unbalanced Input Conditions

针对输入电压不平衡时双级矩阵变换器输出电能质量差且电压传输比低等问题,在空间矢量脉宽调制基础上提出了一种混合型控制策略。整流级采用过调制策略,保证负载侧输出最大功率,逆变级通过时变电压调制系数来实时修正逆变级占空比,确保负载侧三相对称输出,利用Matlab/Simulink对该调制策略下TSMC输出性能进行了仿真研究。仿真结果表明该方法不仅能有效改善非对称输入时输出波形,提高电压利用率,而且算法简单易于实现。

A novel hybrid modulation strategy for two stage matrix converter（TSMC） based on space vector modulation（SVM） was proposed,which can effectively solve the problems of poor power quality and low voltage transfer ratio under unbalanced input voltage conditions.The rectifier stage adopts over modulation strategy to get the maximum DC link voltage.Then the inverter stage adjusts the duty cycles of the inverter by adopting time-varied voltage modulation index to guarantee three symmetry output voltages and currents.The output performance of the proposed modulation strategy was simulated by Matlab/Simulink.Simulation results show that the hybrid modulation strategy can effectively enhance the quality of the output waveforms and improve the voltage utility under unbalanced input voltages.