Integration of Motor Drive and Charger System with Two-phase Motor and H-Bridge Inverter for Electric Vehicle

As electric vehicle (EV) performance continues to improve, the growing number of power converters necessary for connecting various power devices has introduced challenges such as increased part count, weight, and cost. In response to these challenges, this paper proposes a novel motor drive system that integrates AC and DC charging required for EVs. This system composed with Two-phase motor and H-bridge inverter. In the AC charging test, the power factor was 99.5%. In the DC charging test, the output voltage was controlled to be twice that of the input voltage by using the motor as an energy storage element. These results prove that it is possible to integrate AC and DC charging into the motor drive system, potentially leading to more compact and efficient EV designs.

I. Introduction

As EV s become more advanced, power converters capable of connecting to various types of charging equipment are increasingly required. Consequently, this leads to issues such as an increase in the number of components, as well as greater weight and cost. Notably, increasing the system voltage of EV s to 800V reduces charging time during fast charging. However, this approach requires high-power converters to connect with existing infrastructure. On the other hand, the trend toward higher output is also advancing in AC charging. This development requires high-performance onboard chargers, which are equipped with expensive switching devices like SiC. Moreover, initiatives aimed at utilizing electric vehicles as energy storage systems are expanding. These efforts seek to buffer power generated from intermittent renewable energy sources, necessitating the use of bidirectional power converters to achieve this. In this study, we focus on the development of a novel power unit that integrates all power conversion functionalities within the drive motor and inverter. This unit is a system that integrates motor drive functionality with both AC charging and rapid DC charging capabilities. Additionally, it incorporates a mechanism for switching motor winding connections, allowing for a balance between drive output and efficiency. The development of this novel power unit, which integrates such charging capabilities, aims to enhance the performance of electric vehicles while reducing costs.