Study of replacing the traditional electromechanical relay with the full semiconductor solution of bussed electrical center 2019-01-0484
To face the challenges of CO2 emission and automatic driving, the electrical distribution system (EDS), as the basis of all electronic loads, also needs to be constantly changed. Traditional bussed electrical center (BEC) can only supply limited functions such as simple switch and fuse protection, but the full semiconductor solution of smart BEC can provide more accurate diagnosis, faster response, higher reliability with lower power loss and less space.
This paper will introduce the practical role of the smart BEC: in normal operation of the car, smart BEC can detect the voltage and current state of the load. Once abnormal is found, immediate feedback from the smart BEC could make the whole vehicle system respond in time, while the power harness can also be cost optimized. When the car is in parking status, smart BEC can also detect the quiescent current of the loads from KL30 to prevent the trouble of power leakage.
Automated driving is a hot topic, many people focus on the function safety and redundancy of the actuators in the car. However, without the guarantee of power supply, the function will become theoretic. Therefore, this paper will also describe the fail safe and fail operational of power supply with smart BEC.
Of course, replacing traditional relays with semiconductors will face many challenges, such as the switch off energy for inductive load, inrush current for capacitive load, thermal problem of the system, cost optimization and so on. The paper will describes the solutions to these challenges. These solutions have practical significance because they are based on analysis of the loads in the real car.
Finally, the paper will show the actual comparison with the traditional BEC and the smart BEC in terms of weight, size, power loss, wiring saving, and cost in the real car.
Xia Tian, ning shen, Xingwei Wang
Pan Asia Technical Automotive Center, Infineon Technologies China Co Ltd