| 主权项 |
1. A power conversion system, comprising:
a multilevel inverter, including at least one inverter leg comprising a plurality of power stages, the individual power stages comprising:
a DC bus circuit with a first DC circuit branch and a second DC circuit branch,a rectifier circuit providing a DC voltage to the DC bus circuit,an output,a switching circuit including first and second switching circuit input nodes, the switching circuit operable according to switching control signals to provide an output voltage at the output at one of a plurality of distinct output voltage levels, anda precharge and dynamic braking circuit with a resistor connected between the rectifier circuit and the switching circuit, the precharge and dynamic braking circuit operative in a first operating mode to conduct current from the rectifier circuit through the resistor to charge a capacitor of the DC bus circuit, in a second operating mode to bypass the resistor and allow current to flow from the rectifier circuit to the switching circuit, and in a third operating mode to connect the resistor across the first and second switching circuit input nodes in parallel with the capacitor of the DC bus circuit,the outputs of the at least one inverter leg being coupled in series with one another with an output of a last power stage of the at least one inverter leg providing an output to drive a load; and a controller operative to provide the switching control signals to set the individual output voltage levels of the power stages of the multilevel inverter. |
