高频链AC-DC矩阵变换器的变控制频率软开关调制策略

Variable control frequency soft-switching modulation strategy for high-frequency link AC-DC matrix converter

针对高频链AC-DC矩阵变换器的高效率要求,提出了一种变控制频率软开关调制策略。该调制策略在基于零矢量嵌入的分段同步控制策略基础上,以单控制周期平均功率不变为原则,通过改变控制周期长度,并调整一个控制周期内的电压矢量排布,优化脉冲宽度,使变换器在换流时全部开关器件的零电压开通成为可能。通过仿真分析和实验证明,采用本文提出的变控制频率调制策略,变换器在整流和逆变模式下,均可实现网侧电流三相平衡正弦,功率因数达到0.981,输出电压纹波小,最高效率达到96.9%,实现了高性能、高效率运行。

A variable control frequency soft-switching modulation strategy was proposed for the high-efficiency requirements of high-frequency link AC-DC matrix converter.This modulation strategy was developed based on the piecewise synchronous control strategy with zero vector embedded.By considering the principle of constant average power in one control cycle,the length of the control cycle was changed,the voltage vector arrangement in a control cycle was adjusted,and the pulse widths were optimized in the proposed modulation strategy.Hence,it enables the zero voltage switch of all switching devices during commutation.Simulation and experimental results show that the proposed modulation strategy can achieve the sinusoidal grid currents during the rectification mode and inverter mode.The grid-side power factor reaches 0.981 and the output voltage ripples are very small.The highest efficiency of the converter reaches 96.9%.Hence,the high performance and high efficiency operation of the converter are realized.