双向PWM控制，通过PWM控制直流侧的电压以及交流侧的PQ，不受大电网干扰，还具有帮大电网补偿无功的能力。-Bidirectional PWM control, through the PWM control of the DC side of the voltage and the AC side of the PQ, not by the large power grids, but also has the ability to help large power grid compensation.