A Method of Experimental Determination of Parameters of Equivalent Circuits of Induction Motors

Abstract

A method is presented for determining parameters of an equivalent circuit of an induction motor with a squirrel-cage rotor according to data from digital recording of instantaneous values of currents and stator voltage and slip, obtained from usual operational modes of start-up and work under load. Parameters of the stator, magnetization branch, and core loss contour are determined by data of measurements from two or more modes of load conditions with various slips, and the dependence of current displacement coefficients for active and inductive rotor resistances on the slip, from startup mode. Parameters of an equivalent circuit are derived from the iterative-method solution of equations containing the design and measured mode parameters. Examples confirming the efficacy of the developed method are presented.