Implementation of a High-Frequency-Switching Three-Phase PWM Inverter with Separating Heat Sinks

Abstract

Ultra-high-speed motors over 1,000,000rpm have been developed for high-speed compressors and electric turbo-chargers, and these motors demand a higher frequency and sinusoidal current waveform over 10kHz. For example, a three-phase inverter with above 100-kHz switching operation is needed to supply these motors with a 10kHz sinusoidal current waveform. A circuit implementation of a high-frequency-switching three-phase PWM inverter is applied by separating heat sinks. Therefore, this paper focuses on a three-phase inverter using a Si-MOSFETs and SiC-SBD to realize switching operation above 100kHz and discusses both the loss analysis and thermal resistance. Moreover, a laboratory system of the three-phase PWM inverter focused on a cooling structure is produced with separating heat sinks. Finally the experimental results for 300-kHz switching operation rated at 300V and 3.2kVA are presented to verify the separating heat sinks structure.