Second-Harmonic Ripple Voltage Suppression of Integrated Single-Phase Pulsewidth Modulation Rectifier Charging System for EVs

In single-phase ac battery chargers, pulsating power at twice of the line frequency is delivered by the ac source resulting in second-harmonic ripple voltage on the dc-link if additional passive or active filter (AF) circuits are not used. In this article, an inductance-based AF using the leakage inductance of the machine windings along with a current compensation control method is proposed. No additional passive components are required. The machine used in this article has a double-layer winding with a center tap in each phase and the winding structure of the machine is special in that the pulsating magnetomotive force of the whole phase winding can be cancelled when currents flow into the central tap. In this article, the operating principle and control strategy of the AF with the inductive energy storage are analyzed. Finally, a 400-W experimental prototype is developed and the experimental results are used to validate the performance and feasibility of the proposed converter and control strategy.