Virtual Synchronous Motor Based-Control of a Three-Phase Electric Vehicle Off-Board Charger for Providing Fast-Charging Service

• Main Authors: Xiangwu Yan, Jiajia Li, Bo Zhang, Zhonghao Jia, Yang Tian, Hui Zeng, Zhipeng Lv
• Format: Article
• Language: English
• Published: MDPI AG 2018-05-01
• Series: Applied Sciences
• Subjects: electric vehicle; virtual synchronous motor; frequency and voltage regulation; off-board charger; fast charging; equivalent synchronous grid
• Online Access: http://www.mdpi.com/2076-3417/8/6/856

This study introduces a three-phase virtual synchronous motor (VSM) control and its possible application for providing fast-charging service from off-board chargers of electric vehicles (EVs). The main circuit of the off-board charger consists of a three-phase voltage source PWM rectifier (VSR) and a resonant LLC zero-voltage-switching converter. In the proposed control approach, VSM-controlled pre-stage VSR emulates the external characteristics of a synchronous motor (SM), simultaneously, droop control based on charging mode in the VSM can satisfy the demand of the EVs constant-current fast-charging; The post-stage DC–DC converter is responsible for stabilizing the DC bus voltage. The feature of this control strategy is that VSM and fast charging control are implemented by the pre-stage converter, which has better coordination. In the MATLAB, the equivalent synchronous grid of the distribution network supplies to the power battery through the off-board charger, and the effectiveness of the presented control is demonstrated by typical working conditions.