基于三次谐波注入法的三相四桥臂逆变电源

Three-Phase Inverter With Four Bridge Legs Based on Three Harmonic Injection Method

三相四桥臂逆变电源的三相负载可以是任意的,但由于第四桥臂的加入,使控制变得非常复杂。本文介绍了国内外对三相四桥臂逆变电源各种控制方法的优缺点,分析了三相四桥臂逆变电源的调制信号与输入直流电压的关系,提出了一种三次谐波注入法的新的PWM控制方案,同时谐波的注入不会影响输出电流,并能带任意负载。仿真和实验结果证实了该方案的可行性。

The structure of a four-leg three-phase inverter is introduced, and its load is an arbitrary load which can be balanced or unbalanced, linear or nonlinear. With an additional neutral leg, the system control becomes very complex. The merit and demerit of the methods controlled the four-leg three-phase inverter are introduced in the domestic and international field, and the relationship between the modulated signal and source voltage is analyzed. A new kind of PWM control strategy with 3rd harmonic injection is presented, and the harmonics injected are not transferred to the load currents. Simulation and experiment results confirm its validity.