EMI Prevention of CAN-Bus-Based Communication in Battery Management Systems

Abstract — Controller Area Network (CAN) bus has been popularly employed in most of vehicles and it will be heavily involved to the electric vehicle (EV) applications. A vehicle is a noisy system, with electromagnetic interference (EMI) over a wide range of frequencies. EMI generated by the inductive loads is the major cause of performance degradation of CAN bus communications. In order to enhance and protect the reliability and robustness of the CAN bus communication and to maintain safe operation of the battery stack, galvanic isolator is required for the data transmission. This study compares two different galvanic isolators, Optocoupler and Digital Isolator, and three different isolation schemes are evaluated by their protection capability for various EMI affected signals. The best isolation scheme has been recommended for EMI prevention of the CAN-bus-based BMS