一种交错式三电平逆变器的研究

Study on a Interlaced Three-Level Inverter

针对正弦波交流输出的应用场合,提出了一种可降低电感纹波电流的功率管交错并联式三电平逆变电路。该电路需要六个功率开关管,其中上下位置各采用两个功率管并联工作在交错模式,而中间两个位置的功率管则工作在倍频模式。分析了电路的工作原理,提出了其PWM脉宽调制方式。推导了该电路和其他两种常用半桥式逆变电路的纹波电流公式,并对三者进行了比较。阐述并采纳了一种带干扰正馈抑制的逆变器双环控制策略。样机的测试结果证明了电路和系统的有效性。

A new interlaced parallel three-level inverter with lowering inductor ripple current is proposed for sinusoidal output voltage application. This circuit needs six power switches, including two interlaced power switches at the upper location and the lower location separately, and a double frequency power switch at the middle two locations. The circuit theory and PWM method are analysed. The ripple current formula about the proposed circuit and other two half-bridge circuits are deduced and compared. A control strategy with disturbance forward suppression and double control loops is proposed and adopted： A prototype is produced and verified the validity of proposed inverter.