A method to perform a variance-based global sensitivity analysis is presented which allows the investigation of significant design parameters of electrical machines. As matrices with random numbers are required for the calculation of the sensitivity indices, the most frequently used sampling methods which are the random, the latin hypercube and the Sobol’ sequences sampling are discussed in particular. Furthermore, it is investigated which of the sampling methods provides the best coverage of the sampling space. The design parameters are generated randomly from the samples, which can result in unfeasible motor designs. For this purpose a description of the induction machine with squirrel cage rotor using geometric ratios is presented. Finally, a variance-based global sensitivity analysis is performed for the power losses to show its applicability to squirrel-cage induction motors.

Variance-Based Sensitivity Analysis of Significant Design Parameters of an Induction Machine

A magnetic equivalent circuit with a focus on the air-gap is presented. The model takes the slot openings and its effects into account by applying magnetic permeance waves. While the amount of permeance elements in the airgap is significantly increased, the number of nodes, respectively equations and therefore the calculation time compared to a basic model stays the same. Nevertheless, the proposed method makes it possible to determine the magnetic field in the air-gap with a high accuracy, as verified by three different motors.

C. Alteheld

Papers

Analytical Method to Consider the Slot Opening Effects in Nonlinear Magnetic Equivalent Circuits of Induction Machines