Implementation and Experimental Verification of Smart Junction Box for Low-Voltage Automotive Electronics in Electric Vehicles

Abstract

In this study, we designed and implemented a smart junction box (SJB) that was optimized for supplying power to low-voltage headlights (13.5 V) in electric vehicles. The design incorporated a number of automotive semiconductor devices, and components were placed in a high-density arrangement to reduce the overall size of the final design. The heat generated by the SJB was efficiently managed to mount an Intelligent Power Switch (IPS), which was used to power the headlights onto the printed circuit board (PCB) to minimize the impact on other components. The SJB was designed to provide power to the headlights via pulse width modulation to extend their lifetime. In addition, overload protection and fail/safe functions were implemented in the software to improve the stability of the system, and a controller area network (CAN) bus was provided for communications with various components in the SJB as well as with external controllers. The performance of the SJB was validated via a load operation test to assess the short circuit and overload protection functions, and the output duty cycle was evaluated across a range of input voltages to ensure proper operation. Based on our results, the power supplied to the headlights was found to be uniform and stable.