Space harmonics in unified electrical-machine theory

Abstract

The paper deals with the applicability of unified machine theory to electrical machines where space harmonics can not be neglected. It is shown that there exists cases where a linear transformation can de determined to transform the set of time-depended linear differential equations for a machine at constant speed into a set of linear time-invariant differential equations, even if space harmonics are taken into considertation. A criterion for applicability is presented that involves the number of phases, the number of harmonics and the order of the harmonics that have to be considered.