双级矩阵变换器输出电压谐波抑制的仿真研究

Simulation of Output Voltage Harmonic Suppression of Two Stage Matrix Converter

双级矩阵变换器直流环节没有储能元件,因而直流母线电压存在较大的波动。传统空间矢量脉宽调制策略在逆变级调制时采用直流母线电压的平均值,在计算逆变级调制度时将会产生误差,进而导致输出电压与参考电压之间出现偏差。针对上述问题,提出一种逆变级单周期分段空间矢量脉宽调制策略,根据直流母线电压不同时刻的瞬时值,在一个控制周期内对逆变级输出电压进行分段调制,以使得输出电压更接近参考值。在仿真软件中对比了传统调制策略与逆变级单周期分段空间矢量脉宽调制策略的输出电压波形,仿真结果表明所提调制策略下的输出电压总谐波畸变率更低,输出波形更接近参考电压波形。仿真结果证明了所提调制策略抑制输出电压谐波的有效性。

There is no energy storage element in the DC link of the two-stage matrix converter,so there is a large fluctuation in the DC bus voltage.The traditional space vector pulse width modulation strategy uses the average value of the DC bus voltage in the inverter stage modulation,which can cause errors when calculating the modulation ratio of the inverter stage,and then leads to the deviation between the output voltage and the reference voltage.In view of the above problems,a single-cycle segmented space vector pulse width modulation strategy for the inverter stage is proposed.According to the instantaneous value of the DC bus voltage at different times,the inverter stage output voltage was segmentally modulated in a control cycle to make the output voltage closer to the reference value.In the simulation software,the output voltage waveforms of the traditional modulation strategy and the inverter stage single-cycle segmented space vector pulse width modulation strategy were compared.The simulation results show that the total harmonic distortion of the output voltage under the proposed modulation strategy is lower,and the output waveform is closer to the reference voltage waveform.Simulation results prove the effectiveness of the proposed modulation strategy in suppressing output voltage harmonics.