고 전장부하 상황을 고려한 48v 마일드 하이브리드 차량의 동력 제어 방법에 관한 연구

초록

The power consumption is increasing due to the continuous electrification of the vehicle. In particular, the recently realized autonomous drive system consumes about 2.5kW of power, which is an enormous amount of electrical energy. Accordingly, there is a concern that the fuel consumption will be increased when the autonomous drive system is introduced. In order to solve these problems, we propose a Power management strategy for 48V MHEV with the high electric power loads. First, a quasi-static vehicle model that includes the electrical system of the 48V mild hybrid vehicle (12V battery, 48V battery, DC/DC converter, and electric accessory) is developed. Then, Dynamic Programming which is widely used as a global optimal control strategy is performed. Through this, the optimal control inputs Power Slip Ratio and output power of DC/DC Converter are obtained. Lastly, based on the results of the DP, we design a rule-based controller that can be applied in real time. As a result, we can improve the fuel efficiency by optimizing the power distribution control even in the case of high electric power load.