Design of AC Electric Vehicle Supply Equipment based on Safety Standard

Electric vehicle supply equipment (EVSE) is a battery charging system for electric vehicles (EVs). EVSE must be designed to refer to the applicable standards to ensure security and interoperability with various types of EV. This paper explains the design of EVSE for mode 3 AC charging station (CS) based on International standard IEC 61851-1. The design follows the safety requirements on IEC 61851-1, such as overvoltage, overcurrent, and residual current devices to protect persons against electric shocks. Moreover, the charge controller manages the functionality of the devices and their communication so that energy transfers safely. The EVSE is equipped with a human-machine interface (HMI) using Raspberry Pi as the central processor to communicate between CS and EV users. The open charge point protocol (OCPP) is installed for communication between CS and the back-end system; thus, CS can be monitored and managed from the central system. The design is implemented for a 22 kW 3-phase AC EVSE and its testing result demonstrated a successful charging process to the commercial EV, Mitsubishi i-MiEV.