The modules are currently being fitted to Type 1000 cars being built for Tokyo Metro's Ginza Line. Testing is expected to start soon prior to the trains entering service in June.

Mitsubishi Electric says by incorporating silicon carbide power modules in auxiliary power supply systems it is able reduce power loss by 30% and cut transformer noise by 4dB due to a 35% improvement in the distortion rate of output voltage waveforms.

Compared with using silicon, silicon carbide enables the auxiliary power supply system to be 20% smaller and 15% lighter. The main specifications of the new system are a rated voltage of 600V dc, a two-level voltage-type pulse-width modulation (PWM) inverter, an output voltage of 140kVA, and natural air cooling.

The new auxiliary power supply systems use technologies developed for silicon carbide inverters which include high-voltage silicon carbide inverters for 600/750V dc Type 01 trains for the Ginza Line, which were introduced in February 2012, and for Type 15,000 1.5kV dc trains for Tokyo Metro's Tozai Line in January.