A Consideration of Secondary Circuit Parameters of Squirrel-Cage Induction Motors

Abstract

Equivalent circuit parameters are obtained on 19 test motors, whose outputs are in 5.5KW to 6100 hp range of sizes, by which the calculated characteristics such as current, input and slip coincide quite closely with measured ones, and characteristic errors are obtained. Variation of the secondary equivalent circuit parameters with the secondary frequency f₂ is obtained. It is shown that the secondary resistance r₂ increases with f₂ decreases in some motors. Effects of the shape of the rotor slot and magnetic saturation on the secondary circuit parameters are investigated. Effects of the no-load test voltage on the secondary equivalent circuit parameters, and characteristic errors are discussed.