DC voltage regulated PWM inverter for high-speed electrical drives

This paper presents a study on two converter topologies suitable for driving high-speed three-phase electrical machines. In such applications the use of standard inverters with Si-based IGBTs may lead to high switching losses due to the elevated fundamental frequencies of high-speed machines. The use of wide bandgap devices allows reducing losses at high switching frequencies but problems related to EMI and accelerated motor insulation aging may occur. In this work a DC-DC converter is introduced to limit the inverter switching frequency at motor terminals without reducing the sampling frequency of the motor control scheme. This scheme allows to reduce EMI phenomena, and insulation stress on the motor with positive impact also on converter total losses at very high fundamental frequencies. Preliminary experimental results are presented.