Electromagnetic Modelling of High-speed Induction Motors

UoM administered thesis: Master of Philosophy

  • Authors:
  • Roberto Velazquez Velazquez

Abstract

Improvement in the power density of induction machines can be achieved when theyoperate at high rotational speeds using frequency converters that provide a higherfrequency supply to the motor. Applications such as compressors require intrinsicallyhigh-speed operation. In these cases the mechanical integrity is prioritized over theelectromagnetic performance and solid rotors are normally used instead of laminatedrotors so they can withstand the peripheral and radial stresses caused by the high speeds.Small skin depths are associated with solid rotor structures; this complicates theelectromagnetic analysis when FE modelling is used because a fine mesh is typicallyrequired. Although analytical methods in general tend to be less accurate than FE models, they can provide faster and reasonably accurate results.This thesis evaluates the use of an analytical multi-layer model as a preliminary designtool for determining the electromagnetic performance of high-speed copper-coated solidrotors. A simple FE model is developed in order to validate the results obtained from theanalytical model.The input to the analytical multi-layer and FE models is normally current; consequentlythey are modified to work with voltage as the input reference. The multi-layer model iscompared under constant current operation and constant voltage operation. Thelimitations of the analytical multi-layer model are highlighted.

Details

Original languageEnglish
Awarding Institution
Supervisors/Advisors
Award date1 Aug 2017