Trigonometric interpolation at sliding surfaces and in moving bands of electrical machine models

Abstract

Purpose

To propose trigonometric interpolation in combination with both sliding‐surface and moving‐band techniques for modelling rotation in finite‐element electrical machine models. To show that trigonometric interpolation is at least as accurate and efficient as standard stator‐rotor coupling schemes.

Design/methodology/approach

Trigonometric interpolation is explained concisely and put in a historical perspective. Characteristic drawbacks of trigonometric interpolation are alleviated one by one. A comparison with the more common locked‐step linear‐interpolation and mortar‐element approaches is carried out.

Findings

Trigonometric interpolation offers a higher accuracy and therefore can outperform standard stator‐rotor coupling techniques when equipped with an appropriate iterative solver incorporating Fast Fourier Transforms to reduce the higher computational cost.

Originality/value

The synthetic interpretation of trigonometric interpolation as a spectral‐element approach in the machine's air gap, the efficient iterative solver combining conjugate gradients with Fast Fourier Transforms. The unified application to both sliding‐surface and moving‐band techniques.

Citation

De Gersem, H., Ion, M., Wilke, M., Weiland, T. and Demenko, A. (2006), "Trigonometric interpolation at sliding surfaces and in moving bands of electrical machine models", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 25 No. 1, pp. 31-42. https://doi.org/10.1108/03321640610634308