Design and implementation of a high-performance bidirectional DC/AC converter for advanced EVs/HEVs

A high-performance bidirectional DC/AC power converter is required in low emission and high-efficiency propulsion systems such as electric vehicles and hybrid electric vehicles. A general six-switch full-bridge inverter topology with a high efficient interior permanent magnet alternator is adopted to explore the constant-voltage, constant-current and pulsating-current charging processes. In addition, useful information such as maximum conversion ratio, average armature current, armature current ripple and output voltage ripple are derived based on the equivalent circuit model where the armature resistance of the alternator and the conduction resistance of the power switch are considered. A 32 bit digital signal processor, TI 2812, is used to implement the switching strategies and the control algorithms. Experimental results indicate that the performance of the proposed control strategy is satisfactory for all of the popular charging strategies employed. Compared with the traditional claw pole alternator, the proposed strategy exhibits a significant improvement in output efficiency.