Masafumi Iwata

Control charge-discharge using EV and PHEV batteries for power demand reducion

Energy consumption in Japan has been increasing year by year. In particular, energy consumption of the civilian sector and the transportation sector have doubled since the first oil crisis. Recently, energy saving activities, such as the power peak-cut or power peak-shift for the purpose of reducing electricity bills, is carried out. On the other hand, in the demand side of electric power, research and development for the active utilization batteries in electric vehicles (EV) and plug-in hybrid EV (PHEV) is advancing. The mechanism, such as Vehicle to X (Grid, Home, Factory) and X to Vehicle, has been studied to supply power to the facility or receive power from the facility using battery mounted on EV and PHEV. In this research, we have studied the method that the power demand is reduced in the facility by using a battery mounted on EV and PHEV in consideration of the time when EV and PHEV connects to a charger, the time when EV and PHEV disconnects from a charger, and the battery charge when EV and PHEV leaves the facility. We examine the validity of the proposal method with the simulation. As a result, it was confirmed that it can be reduced the power consumption by controlling discharge of the battery mounted on EV and PHEV that is connected to the charger when the unit price of buying electric power is high or power demand is peaking. Also, we compared the proposal method and the general charging method that is implemented in the charger. It was confirmed that it can be reduced the required electricity bills to secure the battery charge when EV and PHEV leaves the facility by about 37% per one vehicle.