A soft switching multilevel inverter drive system and a voltage window switching method for it

摘要

The present invention relates to a smooth switching multilevel inverter drive system and a voltage window switching method therefor. This system includes multi-phase inverter drive circuits. Each phase of the inverter drive circuit includes a number n of DC voltage supply inputs, an AC voltage output, a voltage window circuit, a soft switching inverter drive module, a control module, an inductor and an output capacitor. In operation, the real-time measurement control module is used to compare the AC output voltage and the voltage of each DC supply input, determine the voltage window that the AC output voltage is in, and provide the control signals to the voltage window circuit. The voltage window circuit is used to distribute the DC voltage level at each DC voltage supply input into multiple overlapping voltage windows. The soft switching inverter drive module is used to convert the DC voltage output by the voltage window circuit into AC voltage. The present invention enables the overall system to realize extremely low switching loss and improve the energy use efficiency.