Design and Development of Modified BL Luo Converter for PQ Improvement in EV Charger

The existing chargers for electric vehicles (EVs) use rugged nonlinear diode bridge rectifier to avail dc voltage at the input of dc–dc converter, and introduce serious power quality issues in the input ac current. These issues set the formidable need to improve the power quality (PQ) performance of existing battery chargers by eliminating the input bridge. This is achieved in this work, by the addition of an improved PQ based bridgeless (BL) Luo converter. This power factor correction (PFC) converter is the combination of two Luo converters, which operate independently in the respective half cycles, with common input inductor. The converter provides low cost and high power density based EV charging solution as fewer number of components conduct over single switching cycle due to elimination of input diode bridge in the conventional PFC converter. The charger input current is made to follow the source voltage, exactly in phase and high input power factor is achieved. Moreover, the source current total harmonic distortion is reduced below 5% as per the IEC 61000-3-2 standard under steady state and during sudden variations at load and line side.