Design and development of a bidirectional DC net meter for vehicle to grid technology at TRL-9 level

Electric vehicles as indicated by the recent developments have established a foundation for sustainable transportation. The amount of electricity consumed by the EVs adds a significant amount of loading to the grid. Thus, necessitating the need for simultaneous implementation of vehicle-to-grid infrastructure to protect the grid. In the above circumstances, a bidirectional energy metering system is needed to record the import & export of energy between the grid and the vehicle. Presently the meters are installed on the AC side of the chargers, therefore, losses that occurred during the rectification process are not measured precisely. In this paper, the role of a bidirectional DC measurement system in vehicle-to-grid operation is investigated. The author’s aim is to provide accurate billing to end customers by keeping the DC meter on the battery side. In addition, a net metering scheme is implemented to generate the net bill at the end of the billing period. The proposed DC net meter is developed in compliance with the guidelines mentioned in IEC 61000/60255/62052 standards for low voltage applications. It also has a real time clock to implement the Time of Usage (TOU) tariff. The precision of the DC net meter can be seen from the experimental results obtained from the two bench configuration.