Skin effect experimental validations of induction motor squirrel cage parameters

Purpose – The paper deals with the experimental validations of the corrective coefficient used to take into account the skin effect in the equivalent circuit rotor resistance of induction motors with squirrel cages. Design/methodology/approach – Locked rotor tests have been performed at several supply frequencies on different induction motors; the collected experimental data have been used to validate the rotor parameters analytical estimation obtained by means of a numerical procedure previously proposed by the authors. Findings – The reported analyses regard both open and closed rotor slots. For frequencies up to 80-100?Hz, the reported comparison between experimental and calculated skin effect corrective coefficients shows that the adopted model allows to get satisfactory results in terms of accuracy, lower than 3 percent for open rotor slot machines. The upper frequency limit has to be judged taking into account the objective difficulties to estimate accurate values of the rotor parameters from experimental tests. Practical implications – The proposed algorithm can be easily implemented and added to self-made induction motor design software tools. Originality/value – The proposed procedure allows the computation of the skin effect in induction motor squirrel cage without the use of finite element method approaches.