SIMULTANEOUS SPACE VECTOR MODULATION DIRECT TORQUE CONTROL OF TWO INDUCTION MOTORS USED IN ELECTRIC VEHICLES BY A NINE-SWITCH INVERTER

Abstract

In this paper, a novel two output nine switch-inverter is proposed in order to increase the synchronization speed of induction motors used in electric vehicles (EVs) while improving the efficiency and controllability of the system. The number of switches in the proposed inverter is reduced by 25% compared to double six-switch inverters which conventionally used in EVs. The main characteristics of the considered inverter can be noted as follows: sinusoidal input and outputs, unity output power factor, and specifically, low construction cost due to active switch number reduction. The classical direct torque control method causes torque ripple and speed fluctuations. Therefore, in order to increase accuracy and dynamics of drive system, the SVM-DTC method is proposed, leading to less torque ripple and constant switching frequency. The obtained torque ripple is 2% which is less than the existing structures In order to illustrate advantages of the proposed approach, performance of the EVs in the standard cycles is evaluated.

Keywords

• Nine switch inverter
• EVs
• Direct torque control
• SVM-DTC