Development of Low Loss Inverter System Adopted Lower Harmonic Losses Technology and Ultra Compact Inverters Adopted High Power Density SiC Module

Abstract

We have developed energy-efficient traction power supply systems and traction systems through the use of compact inverters that use low-loss power devices based on a new material, SiC, as well as electric motors designed for lower harmonic losses and the development of PWM control techniques. The energy consumption rate for a railway vehicle achieved by using SiC modules, induction motors with lower harmonic losses, and PWM control, and by expanding the area outputting regeneration torque, was 37.1% lower relative to conventional systems when tested on existing rolling stock operating on suburban and commuter lines. We developed new 3.3 kV/800 A SiC power modules. The weight of the developed inverter has been reduced by 55% of a conventional IGBT inverter, by adopting a SiC module, a compact cooler and a lightweight oil-free capacitor.