Design of an integrated EV on-board charger with a wide output voltage range

Abstract

This paper introduces the design and implementation of a novel integrated on-board electric vehicle charger with a wide output voltage range. The work addresses the need for a universal integrated on-board battery charger that can charge batteries of different voltages for electric vehicles. The charger utilizes the existing traction inverter and motor to provide a charging function while eliminating the need for extra costly equipment. The 2.5kW charger consists of two stages: an AC/DC stage and a DCDC stage. The AC/DC converter regulates the input voltage to a 400V DC output. The DC/DC stage executes buck and boost operations and provides a wide 200V − 800V output range accommodating present and future high-voltage batteries. The charger has a closed loop control strategy for the boost section that ensures a steady and regulated output and an open loop control approach for the buck for a simplified design. Through simulations in MATLAB/SIMULINK, the charger demonstrates effective voltage regulation in boost (800V ) and buck (200V ) modes with a peak-to-peak ripple within 1-2%of the nominal values. Further work involves constructing a physical prototype to validate the simulated results.