Japan-based Mitsubishi Electric has started testing of railcar traction converter/inverter systems with all-silicon carbide (SiC) power modules installed on a N700 Shinkansen bullet train for Central Japan Railway Company (JR-Central).
According to the company, these are believed to be the first 3.3kV 1,500A tractions systems of this type to be installed on a high-speed train line.
The company said it has been working to downsize its traction system for Shinkansen bullet trains.
By using SiC power modules, the company said it has been able to reduce the size of its new converter/inverter system by 55% and its weight by 35% compared with existing traction systems, while the weight of the traction motor has been reduced by 15%.
The main circuit has an input voltage of 2,500V AC, with large-capacity, all-SiC power modules and a three-level PWM inverter with regenerative braking.
It also features four 305kW self-cooling traction motors are controlled in parallel.
The company has developed the power modules with support from the New Energy and Industrial Technology Development Organization of Japan.
Mitsubishi’s new traction inverter with SiC power modules, using SiC transistors and SiC diodes, were initially installed on Odakyu Electric Railway’s four-car 1000 series trains.
Results from these tests showed a 17% power saving and a 34.1% increase in the vehicle’s energy-saving capability.
Mitsubishi is focused in the manufacture, marketing and sales of electrical and electronic equipment used in information processing and communications, space development and satellite communications, consumer electronics, industrial technology, energy, transportation and building equipment.
Image: JR-Central N700 Shinkansen bullet train. Photo: courtesy of Mitsubishi.