Vector Control Method for Induction Motor of Electric Vehicle under the Constraint of Battery Output Power

Abstract

Vector control is a most widely used control method for induction motor (IM) of electric vehicle (EV). However, the EV battery voltage will rapidly drop to the under-voltage protection point, if the IM torque is output without any limited, especially when the EV battery level is insufficient. As a result, the under-voltage protection of IM driving system would be trigger in advance and the EV endurance will be seriously affected. To address this issue, a vector control method for EV under the constraint of battery output power is proposed. Based on the traditional vector control strategy, this method introduces the closed-loop control of battery output power and combines the power limit curve associated with motor speed and battery voltage to constrain the battery output power. The experimental results show that the proposed vector control method can effectively prevent premature under-voltage protection caused by excessive battery output current, and is helpful to improve the endurance of electric vehicles.