Hitachi & Hitachi Astemo Researchers Lauded for Inverter Development 

Researchers and engineers with Hitachi and Hitachi Astemo were honored recently for their development of a compact high-power density inverter for electric vehicles and plug-in hybrid vehicles. Now the companies plan to expand the use of the inverters, which are designed with certain magnetic technologies for some of their key functionality, into data centers and other fields requiring compact solutions. 

The 800-volt inverter uses magnetic technology in that a noise filter using coils is installed to reduce electromatic interference and magnetic materials are used for their cores, while a direct water double-sided cooled power module plays an important role in cooling the inverter. 

High power density inverter and direct water double-sided cooled power module 

The companies were awarded the distinguished Okochi Memorial Prize in March for their efforts. For the widespread adoption of EVs, it is necessary to reduce charging related concerns and to improve performance and driving range, notes Hitachi. Achieving these aims requires compact drive systems with high-power density and high voltage, which deliver superior cooling performance and help to shorten charging times. The inverter harnesses Hitachi’s concept of direct water double-sided cooling with was commercialized in 2014 and went into mass production in 2019 as 800-volt compatible units for EVs. The inverters have already been fitted to more than 300,000 EVs and PHVs.

The product was jointly developed by Hitachi and Hitachi Astemo. Headquartered in Tokyo, Hitachi Astemo is a joint venture between Hitachi, Ltd. and Honda Motor Co. Hitachi Astemo is a technology company that develops, manufactures, sells and services automotive and transportation components, as well as industrial machinery and systems. For more info, see and