A novel medium-voltage drive system adopting PWM-SHE technology

High performance high-power converters are always a challenge to manufacturers. Although the dramatic improvements in switching devices have been achieved, one still has to face the dilemma-the need for “clean” power supply requires high switching frequency of devices. On the other hand, the high switching losses limit the switching frequency to a relatively low range. Pulse width modulation-specific harmonic elimination (PWM-SHE) switching patterns can promise high quality output, while keeping the switching frequency lower than other PWM schemes. Therefore, combining PWM-SHE methods with new HV-IGBT technology and suitable topologies for both inverter and active-front-end rectifier, one can find a viable solution to the medium-voltage high-power drive systems. In this paper, a neutral-point-clamped (NPC) voltage source PWM inverter topology has been adopted for medium to high voltage applications