Tokyo-based Mitsubishi Electric Corp says that its traction inverters incorporating all-silicon carbide (SiC) power modules, installed in a 1000 Series urban commuter train operated by Japan's Odakyu Electric Railway Co Ltd, have been verified to achieve an approximate 40% savings in power consumption compared with a train using conventional circuitry.
The traction inverter, which is rated for 1500VDC 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 the power consumption and electric power regeneration ratio of the two cars' main circuits, which comprise traction inverters, high-efficiency main motors and filter reactors.
Between 17 January and 8 May, the following results (average values) were recorded: a 17% power saving during powered operation; an increase from 34.1% to 52.1% in the 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.
