Closed-loop regenerative efficiency testing with electric vehicle bidirectional DC-DC converter

Bidirectional dc-dc converters have been widely used in hybrid electric vehicles (HEV), fuel cell vehicles (FCV), and electric vehicles (EV). In this paper, a 60 kW, three-phase, bidirectional dc-dc converter prototype for electric vehicle is presented along with experimental results. One important evaluation criterion for any converter is efficiency. Due to the high-power level and the bidirectional characteristic of EV bidirectional dc-dc converter, high power sources and compatible electric loads for both high and low side terminals are needed for efficiency testing; however, such equipments may not be easily available. In order to eliminate the need for high power source and loading equipments and to achieve high accuracy efficiency measurement, a regenerative efficiency testing method is employed. Also, the regenerative efficiency measurement is performed under closed-loop condition that yields consistent and repeatable efficiency test results.