SiC Railcar Traction Inverter Achieves 40% Power Savings

June 21, 2015 by Jeff Shepard

Mitsubishi Electric Corporation announced today its main circuits featuring traction inverter made with all-silicon carbide (SiC), which were installed in a 1000 series urban train operated by Odakyu Electric Railway Co., Ltd. in Japan, have been verified to achieve an approximate 40-percent savings in power consumption compared to a train using conventional circuitry. The traction inverter, which is rated for 1,500Vdc catenaries, was tested over a four-month period.

The verification compared a car retrofitted with an all-SiC traction inverter and another car fitted with a conventional gate turn-off thyristor traction inverter, both of which were put into actual commercial service. The test measured power consumption and electric power regeneration ratio of the two cars' main circuits, which comprise traction inverters, high-efficiency main motors and filter reactors.

The following results are average values measured between January 17 and May 8, 2015: 17% power savings during powered operation; Increase from 34.1% to 52.1% in power regeneration ratio, calculated as power from regenerative brakes to catenaries divided by total electric power to drive the rail car; and 40% power savings overall

Specifications of Main Circuit include: Input voltage, 1,500Vdc; Main circuit system consists of large-capacity all-SiC power modules with a two-level pwm inverter with regenerative brakes; Control system, four traction motors with 190kW and parallel control.