Hitachi, Ltd. Introduces Full SiC Inverter for Automotive Applications

Hitachi, Ltd. and Hitachi Automotive Systems announced on September 28, 2015 that they have developed high-efficiency, high-power inverters for hybrid and pure electric vehicles. Compared with Hitachi’s original product, the new product’s power consumption is reduced by 60%, and the power capacity under the same volume is increased by about 2 times. Helps achieve long-distance driving and improved acceleration.

This time, Hitachi used previously developed SiC and GaN parallel packaging technology and double-sided cooling power module technology to develop a full SiC power module and an HEV/EV inverter using this module. In order to equalize the switching time of each SiC power semiconductor, previously developed parallel packaging technology was used. In other words, a wiring board having the same length of control signal lines connected to each SiC power semiconductor has been developed, and the resistance characteristics of the respective wirings have been balanced. As a result, the low resistance characteristics of the SiC power semiconductor can be fully utilized, and the power capacity can be expanded.

In addition, the inverter developed this time adopts a structure in which overlapping wiring is used to reverse the direction of the load current and is enclosed in a can-shaped metal cooling fan of a double-sided cooling power module. In this way, the magnetic field formed by the built-in wiring is eliminated by the cooling fan, and the magnetic field energy accumulated in the wiring is reduced.

In addition, the double-sided cooling type full SiC module developed this time will be exhibited on October 30th at the "44th Tokyo Motor Show 2015" held by Tokyo Ariake International Convention and Exhibition Center. (Reporter: Yutaro Kojima)