On the Feasibility of Integrated Battery Charger Utilizing Traction Motor and Inverter in Plug-In Hybrid Electric Vehicles

For the practical use of an integrated battery charger (IBC), this paper proposes an improved IBC based on a detailed analysis of the conventional IBC with respect to the inherent limitations such as switching frequency, motor inductance, common-mode noise, power loss, and input current and voltage sensing. Moreover, battery charging performance according to pulse-width-modulated switching schemes is mathematically analyzed and explained. The informative simulation and experimental results are provided with the traction motor/inverter hardware of an actual plug-in hybrid vehicle.

I. Introduction

Ecofriendly vehicles, such as electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), require battery chargers to supply electric energy for the recharging of the high-voltage battery pack [1]–[8] . Generally, they are classified into on-board type and stand-alone type [2] . Stand-alone types are located at charging stations and usually provide the maximum allowable continuous battery power. On the other hand, on-board types are mounted on the vehicles, and the charging power is limited by the standard household power. Despite this low charging power, an on-board charger (OBC) is considered one of the main components of ecofriendly vehicles because it enables drivers to charge the batteries anywhere and anytime with a household outlet. However, the complicated hardware components, such as power factor correction (PFC) converter, dc–dc converter, high-frequency transformer, passive components, etc., increase the cost, weight, and volume of the vehicles.