A Detailed Procedure of Squirrel-Cage Three-Phase Induction Motor Parameter Estimation Using Polynomial Regression
Induction motors are the most frequently used electrical motor in high-performance drive systems. The vector and sensorless speed control schemes of induction motors usually require exact values of motor parameters to obtain the robust control. This paper proposes an effective offline estimation of the equivalent circuit parameters of squirrel-cage three-phase induction motors using time-varying stator voltage and current with different load torques. The relationship between the input impedance and the slip rate can be expressed as a fractional polynomial. Based on conditions for obtaining the minimum of the objective functions, the motor electrical parameters can be conveniently estimated. The mechanical parameters of the motor can be derived by using determined electrical parameters and motor dynamic simulation using MATLAB/Simulink. The main advantage of this method is that it could facilitate us to gain the optimal values of the motor parameters without the need of any initial values. In addition, the effectiveness of the proposed method can be validated by a low-cost experimental system.
