DENSO Corp. (Tokyo, Japan) has developed four new components for hybrid vehicles: a hybrid control computer; a battery-monitoring unit; a dc-dc converter, and an electric compressor for air-conditioning systems. In March, the Harrier hybrid and Kluger hybrid vehicles of Toyota Motor Corp. (Japan) were launched in Japan with the new components installed. Next, the components will be introduced in the United States on the Lexus RX400h and Toyota Highlander hybrid.
The new battery-monitoring unit monitors the main battery’s condition, including voltage, current and temperature, which traditionally were performed by the battery ECU. The battery-monitoring unit was designed separately from the hybrid control computer, because the battery-monitoring unit needs to be installed close to the main battery.
The dc-dc converter is approximately 10% smaller than a conventional dc-dc converter, but its increased output current from 100 A to 120 A is able to respond to the electric power needs of larger vehicles. DENSO achieved the increased output current by adopting a new circuit control technology to reduce energy loss in the converter. To handle the increased output current, DENSO improved the converter’s power elements by changing the mounting method from soldering to welding. Customized integrated circuits reduce the area of the converter’s circuit board by approximately 40%, contributing to the 10% converter size reduction.
