Kinya NAKATSU, Ph.D. (Eng.)
Senior Chief Researcher,
Hitachi, Ltd.
Kinya Nakatsu is currently a Senior Chief Researcher in the Center for Technology Innovation (CTI) – Controls, of the Research & Development Group of Hitachi, Ltd.
Nakatsu joined Hitachi Research Laboratory in 1994 after completing his master’s degree electrical engineering at Tokyo University of Science. He engaged in research for industrial equipment, rolling systems and railway power modules, automotive inverters, uninterruptible power supplies (UPS) and elevator systems, contributing to technology development for high-reliability low-loss power devices, high speed and high-current electric circuit implementation using eddy current, a CPU integrated system power device. He then pursued work in electro-motorization technology to promote decarbonization of automotive vehicles, developing a world-leading direct water-cooled power module that drastically improved the cooling performance of power devices, and implemented this in an inverter. This technology was widely adopted by automotive manufacturers, such as GM and Daimler, and is being used worldwide in hybrid electric vehicles (HEV). He then pursued research on high output power density inverters necessary for electric vehicles (EV), developing new technology such as thin-film insulating material with high thermal conductivity, friction stir-welding, and organic to inorganic material bonding, resulting in the world’s first direct water double-sided cooled power module that achieved a high power output density of 94.3kVA/L, 2.7 times that of conventional technology at the time. The technology developed was adopted by Audi and other manufacturers in 2019 and is contributing to technology development for decarbonization.
Nakatsu received his doctoral degree in Material Science from Ibaraki University in 2014. He is a member of IEEE, the Institute of Electrical Engineers of Japan (IEEJ), Society of Automotive Engineers of Japan (JSAE), and the Institute of Electronics, Information and Communication Engineers (IEICE). Nakatsu has contributed to over 14 scientific papers, and has over 90 patents in Japan and overseas.
