Control of induction motors for wide speed range for electric vehicle drives

A control scheme for induction motors suitable for electric vehicles is presented. The proposed scheme allows the motor to exploit the maximum torque capability in the whole speed range, shows a weak dependence on the motor parameters and is robust against fast variations of the dc-link voltage. It is based on a control algorithm that decreases the rotor flux as the requested voltage tends to overcome the available voltage. The proposed scheme produces a smooth transition into and out of the flux weakening region and a fast torque response. The feasibility of the whole control scheme is confirmed by experimental tests.