Topology and controller of an isolated bi-directional AC-DC converter for electric vehicle

An isolated, single-stage bidirectional AC-DC converter for electric vehicle battery charger is proposed. The topology utilizes two half-bridge circuits and a series resonant LC circuit in between. The proposed topology uses only six switches. Low component count in the circuit results in lower cost and volume. Control methods using variable phase-shift and duty-cycles of the half-bridge circuits are proposed. They transfer the desired power and obtain ZVS for all the switching instants while minimizing the RMS current through the resonant circuit and switches. ZVS operation of the circuit enables the switching frequency to increase, without increasing the switching losses. This will result in smaller reactive components and transformer. The proposed controllers also obtains the best performance out of the circuit. Simulation results with PSIM and experimental results to verify the theory have been done.