三相谐振直流环节逆变器的控制策略

本文针对三相谐振直流环节逆变器提出了三种电流调节方案,并对这三种调节方案进行了分析比较。电流调节△调制方案是零滞环的,它使得三相电流总是流向正确的方向,具有良好的动态特性,但谐波特性较差;相邻模态电流调制方案使逆变器在相邻的开关模态或零开关模态之间进行切换,谐波特性很好,动态特性不够好,而滞环控制电流调制器根据逆变器的实际情况选择开关模态(包括零模态),具有良好的动态特性和谐波特性,适用于三相谐振直流环节逆变器。文中给出了三种方案下的仿真波形,仿真结果的比较也于文后给出。

Control Strategies for Three-Phase Resonant DC Link Inverters

Three kinds of current regulator are presented for three-phase resonant dc link inverters (RDCLI) in this paper. The current regulated delta modulator (CRAM) is a zero hysteresis switching regulator. It drives all three-phase currents in right direction at all times and is good in dynamic response, but poor in harmonic characteristics owing to the absence of zero state. The adjacent state current modulator (ASCM) switches between adjacent switching states and the zero state. It is better in harmonic characteristic but not satisfactory in dynamic response. The hysteresis controlled current modulator (HCCM) se-lects the switching states,including the zero state,according to the actual condition,and both the dynamic response and harmonic characteristics are satisfactory. Therefor HCCM is suited for three-phase RDCLI. The simulation waveforms are given in this paper,so are the comparison of output voltage and its harmonic characteristics under the three kinds of current modulator.