一种简化换流的双级矩阵变换器混沌载波频率调制技术

A Chaotic Carrier Frequency Modulation Technique of Two-Stage Matrix Converters with Simple Commutation

针对恒定载波频率调制的双级矩阵变换器(TSMC)输出电压含有高峰值离散谐波,产生电磁干扰的问题,本文首次将混沌载波频率调制技术(CCFMT)应用于TSMC来扩展谐波边带,降低谐波峰值。分析了CCFMT调制前后输出电压频谱和输入输出电流纹波的变化。但是,CCFMT会增加TSMC产生窄脉冲的几率,增加换流难度。为此,本文使用整流级含有零矢量的调制方式,延长了整流级零电流换流时间,并且适当选择调制波和载波形状,简化了换流过程。建立TSMC实验平台,表明本文提出的调制技术能够有效地降低输出电压谐波峰值。

The two-stage matrix converter （TSMC） with fixed carrier frequency has discrete and high peaks in the spectra of output line voltages, which produce powerful electromagnetic interference. In this paper, a chaotic carrier frequency modulation technique （CCFMT） is applied in TSMC for the first time to spread sideband range and suppress harmonic peaks. The spectra of output voltages were analyzed and ripples of input and output currents are also studied. However, the CCFMT will increase the difficulty of commutation. Thus, the rectifier in TSMC uses the PWM modulation containing zero vectors to extent zero current commutation time, and carrier and modulation waveforms are also properly chosen to simplify commutation processes. An experimental platform is designed and experimental results show that harmonics of line voltages are efficiently suppressed.