Speed sensorless, efficiency optimized control of induction motor drives suitable for EV applications

Electric motors, those are used with the electric vehicles must have high efficiency for maximum utilization of the energy from the batteries and/or fuel cells. Also to be popular, these motors must be compact, lightweight, less expensive and may be recycled very easily. Furthermore, to have increased safety and reliability, it is better if the speed sensor is dispensed with. All these aspects calls for an efficiency optimized, speed sensorless control technique that offers sufficiently high performance. This paper presents one such control technique for the Induction Motor to make it suitable for the EV applications. The efficiency optimization is based on the measurement or estimation of the active power input to the machine while the speed sensorless algorithm is developed utilizing the reactive power. Simulation results and experimental results are presented.