Auxiliary Power Supply System for Electric Power Steering (EPS) and High-Heat-Resistant Lithium-Ion Capacitor

Advanced Driver Assistance System (ADAS) and Automated Driving (AD) are the two major topics for the current and next generations of vehicles. To realize them in full-size vehicles equipped with a 12 V power supply, the need for electric power steering (EPS) is increasing. Currently, the steering system of full-size vehicles is equipped with hydraulic power steering due to electric power shortage. An auxiliary power supply system using a lithium-ion capacitor was developed in order to solve the concern. In addition, to mount the system in the vehicle with no cooling−heating equipment, development of expanding the operating temperature range of the lithium-ion capacitor was conducted. Several improvements have made the capacitor operate stably in high-temperature environments above 100 °C.