Optimization of Induction Motor Equivalent Circuit Parameter Estimation Based on Manufacturer’s Data

Abstract

This paper presents a two-stage optimization of the parameters of a seven-parameter equivalent circuit of three-phase induction motor. The initial parameters of this equivalent circuit are estimated by a method called the Engineering Method using the data given in the manufacturer’s data sheet. The two-stage parameter optimization procedure was developed to minimize the errors between the estimated and the actual values in motor torque and current. In the first stage, the method is targeted to optimize the parameters of the stator only. The second stage, if necessary, aims at optimizing the rotor-circuit parameters. Normalized least squares method is used to formulate the optimization problem. An objective function is established to minimize the errors between the calculated starting torque and current and the pullout torque and the given values in the manufacturer’s data sheet. The model parameters of ten industrial induction motors are estimated without and with optimization. The obtained results are compared with the Engineering Method and the actual manufacturer’s data to verify the effectiveness of the proposed method.