Robust torque control of induction motor for electric vehicle

Direct torque control is an emerging technique for controlling the PWM inverter-fed induction motor (IM) drives. It allows the precise and quick control of the IM flux and torque using only the stator voltage and current, i.e. sensorless speed control. Combining the variable structure system and Lyapunov design a new discrete-time control algorithm is developed. It possesses all the good properties of the sliding mode and avoids the unnecessary discontinuity of the control input, thus eliminating chattering. All the theoretical issues are verified by the distinctive feature of the simulation and experiment. The drive system, including an 18 kW, 4 pole, 6000 RPM, 120 V battery-powered IM and a 30 kVA IGBT inverter, has been applied to a pick up truck.