Integrated battery charger with power factor correction for electric-propulsion systems

This paper proposes an on-board integrated battery charger for an electric-propulsion system. The system includes a rectifying diode bridge, an inverter, a permanent magnet motor, a digital signal processor, a battery set and three relays. By suitably controlling the three relays and the power switches of the inverter, the proposed system can be operated as either an electric-propulsion system or a battery charger. The integrated battery charger can be used to charge a 48 V battery set or a 192 V battery set from a single-phase 110 V rms grid. The battery charger can be operated in a boost-converter charging mode or in buck-converter charging mode with input power factor higher than 0.9 when operating with 48 V battery or 192 V battery, which can meet the IEC 1000-3-2 standard. Only a diode bridge, an inductance-capacitance (LC) filter, and three additional relays are required in addition to the components for propulsion. The windings of the motor and the power switches of the inverter are shared for both the electric-propulsion system and the battery charger. A digital signal processor, TMS-320-F-2808, is used to execute all of the control algorithms. Experimental results validate the theoretical analysis and separately show the correctness and feasibility of the proposed method.