Direct torque control versus indirect field-oriented control of induction motors for electric vehicle applications

Abstract

Performance and energy efficiency of induction motors (IM) used in electric vehicle (EV), by applying two control methods, namely the indirect field-oriented control (IFOC) method and the direct torque control (DTC) method, are compared. The tracking accuracy under changing vehicle speed circumstances for different speed controllers (classical PI, fuzzy logic, and sliding mode speed controllers) is studied. The EV including IM and battery is considered a nonlinear system. For modelling and simulation of EV components and for evaluating the controller performances, a Matlab m-file code package based only m-file coding is developed. The simulations reveal the advantage of DTC over IFOC and the superiority of the proposed sliding mode controller, in terms of improved tracking accuracy and increasing energy efficiency, and motivate the use of the proposed sliding mode controller for EV applications.

Keywords

• Electric vehicle
• Induction motors
• Fuzzy control
• Vector control
• Sliding mode control