基于补偿函数的SPWM矩阵变换器控制策略

应用矩阵变换器的交直交等效模型,在其交直和直交2个虚拟环节上,分别采用不控整流和SPWM2种简单易实现的调制方式。在三相输入电压对称或非对称的情况下,虚拟整流环节输出的是直流波动电压,为消除此直流波动电压对虚拟逆变环节SPWM调制输出的电压、电流波形的影响,利用开关函数概念推导了对SPWM的调制波进行补偿的补偿函数。其原理是通过向调制波中注入反极性的、幅值随直流波动电压瞬时值变化的正弦波来消除输出电压中的低次谐波。该方法同样适用于输入电压非对称的情况,而且其硬件实现电路简单。应用Matlab/Simulink进行了仿真,仿真结果表明在输入电压对称或非对称的情况下都能获得良好的输出电压波形,验证了所提控制算法的正确性。

SPWM control based on compensation function for matrix converter

Non - controlled rectification and SPWM(Sine Pulse Width Modulation) are applied to the virtual rectifier and virtual inverter of matrix converter equivalent AC / DC / AC model respectively. Virtual rectifier generates fluctuant DC voltage when symmetric or unsymmetric three - phase voltages are supplied. In order to eliminate the effect of the fluctuant DC voltage on the SPWM output voltage and current of virtual inverter,the compensation function is deduced for modulation wave based on the concept of switching function. The principle is that,a sine wave,which follows the fluctuant DC voltage with reversed polarity,is injected to the modulation wave to eliminate the low harmonics of output voltage. This method is also applicable to unsymmetric input voltage condition and its realization is very simple. Simulations with Matlab / Simulink show that,high quality output voltages are obtained under both symmetric and unsymmetric three - phase input voltage conditions,which verifies the validity and effectiveness of the proposed control method.