ABSTRACT
This paper presents some of the results of investigation of various designs of commercial variable transformers used as voltage stabilisers. The investigation is carried out by 3D finite element (FE) modelling and computation of nonlinear magnetic field distribution in various designs of such transformers. The effects of electromagnetic and geometric parameters, and various operational regimes (brush and tap positions) on the distribution of magnetic field and saturation level in the core are calculated and discussed. Their effects on magnetic field distribution in the air above the core are also discussed. These factors ultimately define the overall size and performance of the voltage stabilisers investigated in this paper. Results are presented in terms of flux plots and design curves.
