Research of smart charging management system for Electric Vehicles based on wireless communication networks

With the rapid development of Electric Vehicles (EVs), large-scale charging requirement will heavily impact the existing power grid. So there is an urgent need for coordinating control to avoid it in smart grids. Demand side management reducing charging rate at peak load and rescheduling charging process at appropriate time such as low grid load can be used to solve this issue. This paper proposed a coordinating control charging management system for EVs charging station, which is comprised of single-node charging controllers and a centralized management system. Electric Vehicle Charging Controller (EVCC) implemented via PWM signal to control charging current and charging time. As a crucial component of centralized control, Smart Electric Vehicles Charging Management System (EVCMS) obtains charging data and transmits control instructions via ZigBee and GPRS wireless communication networks technology. For calculating the charging current that each EV needs, a model of battery State-Of-Charge (SOC) is included, and each EVCC gets initial battery SOC, battery capacity and other data through CAN-Bus. In the end, the design of ZigBee and GPRS is discussed, and this two-way wireless communication networks is low power consumption, small size, high reliability, and easy expansion.