Control Method of Dual Inverter System for EV with One Battery

Abstract

A control method for electric vehicle (EV) of a dual inverter system with one battery is proposed. The conventional dual inverter system consists of an open-end winding motor and two inverters, and each inverter is powered by an independent battery. In the case of a battery failure, it can be operated as a multi-level inverter by controlling the voltage of the smoothing capacitor on the failure side to half of the battery voltage, and improvement in system efficiency can be expected. However, it is difficult to maintain the capacitor voltage at half of the battery voltage across the entire operating region of the EV. Therefore, a control method that switches between single inverter operation and dual inverter operation according to the operating conditions, and respond to changes in the capacitor voltage during operation switching is developed. The developed control scheme is demonstrated by hardware in-loop simulation and an experimental vehicle.