Rotor position and speed estimation for a synchronous reluctance motor drive using dual current-slope technique

This paper proposes a dual current-slope rotor position estimation and its relative sensorless closed-loop drive system for synchronous reluctance motors. First, the mathematical model of the synchronous reluctance motor is discussed. Then, a new rotor position/speed estimator of the synchronous reluctance motor is proposed. The proposed method uses dual current-slope to estimate the rotor position and rotor speed for a synchronous reluctance motor. In addition, the estimator can easily be realized and is unrelated to the motor parameters. The estimating technique does not require any extra hardware circuit when compared to the traditional drive system. A TMS-320F-28335 digital signal processor is used to execute the rotor position/speed estimation, the position or speed control algorithms, the d-q to a-b-c coordinate transformation, and the PWM switching strategy. The hardware circuit, therefore, is very simple. Several experimental results are provided to validate the theoretical analysis.