A Study on Hybrid Energy Storage System for 42V Automotive Power-net

There are lots of attempts in automotive field to supersede mechanical parts with electrical ones owing to increasing needs of drivers' safety, comfort and convenience as well as recent tightened environmental regulation. In addition, continuous improvements of semiconductor technology make it speed up to use electric components instead of conventional mechanical and hydraulic ones. In accordance with these tendencies, the demand of electric power and energy used in vehicle has been increasing steadily, and it will cause overburden of conventional 14 V power generation and distribution system. A research on higher voltage system started in early 1990s and 42 V power system has been introduced for a future automotive power-net. In this paper, technical trend in energy storage system which implies one of the key technologies to implement 42 V power-net is reviewed, and development results of the improved energy storage system consisted of ultracapacitor, battery and management controllers are presented