BRIDGELESS MODIFIED BOOST CONVERTER TO IMPROVE POWER FACTOR IN EV BATTERY CHARGING APPLICATIONS

Abstract

This work offers another approach to conventional boost converter without bridge for improving the input power factor and the charger performance of electric vehicle battery charger. In most power electronic- based battery chargers, diode bridge rectifier circuit is employed. Hence, many harmonics exist on the input side, which reduces efficiency. The innovative scheme based on two original boost-converter during positive and negative line half cycle does not contain diode bridge rectifier. To make this happen, the introduced system uses two boost converters in different switching cycle to reduce the conduction losses and lower the input current harmonic, and It also simplifies the circuit by having only on control circuit with voltage-sensing feedback control. The converter will run most of the time in the discontinuous conduction mode. So that the circuit can be designed with smaller components with less ripple. The simulation as well as the experiment results show that this circuit retains unity power factor and low total harmonic distortion while providing a steady DC voltage, which is suitable for the charging technique of constant current and constant voltage.