Comparison of PWM Based Modulation Techniques for Dual Active Bridges

Isolated bidirectional DC-DC converters (IBDCs) have found wide utility in the area of high-powered AC to DC energy conversion applications due to its power factor (PF) correction capabilities, inherent soft switching ability and low voltage stresses on switching devices. High PF correcting abilities is due to low THD (total harmonic distortion) in input. This paper attempts to compare the performance of a Dual Active Bridge (DAB) for various PWM (Pulse Width Modulation) techniques. These control strategies have been reviewed from many aspects based on leakage inductor, shunt capacitor and switching devices. Parameters such as switching efficiency, ease of implementation and ZVS switching region among others are evaluated. A simulation is performed on a 10 KHz, 18 KW DAB to compare Single Phase Shift and Trapezoidal Phase Shift (TPS) modulation techniques. Results affirm that TPS displays superior performance during light loads including at transient switching states.