Power converting apparatus

摘要

A power converting apparatus includes a first inverter circuit including a high-voltage first DC voltage source and operated at a low frequency using Si IGBTs having a high withstand voltage exceeding 1000 V and a second inverter circuit including a low-voltage capacitor operated by high-frequency PWM using SiC MOSFETs having a low withstand voltage, wherein an AC side of the first inverter circuit is connected in series to an AC side of the second inverter circuit. The power converting apparatus outputs AC power having a prescribed voltage waveform obtained from the sum of voltages generated by the first and second inverter circuits.

主权项

1. A power converting apparatus comprising:
a first inverter circuit provided with a first DC voltage source and a plurality of Si semiconductor switching devices; and a second inverter circuit provided with a second DC voltage source and a plurality of semiconductor switching devices; wherein: all of the semiconductor switching devices of said first inverter are Si semiconductor switching devices, and all of the semiconductor switching devices of said second inverter are non-Si semiconductor switching devices made of a semiconductor material having a wider band gap than silicon, said first DC voltage source has a voltage higher than a voltage of said second DC voltage source and a switching frequency at which said first inverter circuit is driven is lower than a switching frequency at which said second inverter circuit is driven, and AC side output terminals of said first inverter circuit and AC side output terminals of said second inverter circuit are connected in series, and AC power having a prescribed voltage waveform obtained by combining outputs of said first and second inverter circuits is supplied to a load.