Dual-DSP sensorless speed control of an induction motor with adaptive voltage compensation

This paper presents a new sensorless speed control scheme for adjustable AC induction motor drives. In the proposed scheme, rotor flux oriented vector control is used to decouple nonlinearity of the induction motor and a stator flux-based flux estimator is used estimate the synchronous speed. The motor speed can be estimated using only the phase currents and DC-link voltage. An adaptive voltage compensation scheme is proposed to compensate the nonlinearities resulting from the PWM inverter and eliminate the time delay of conventional line voltage sensor filters. A dual-DSP based digital control development system has been used realize the proposed sensorless control scheme. Experimental results show the proposed sensorless speed control scheme can achieve fast transient responses and at the same time maintain a wide speed control range