Influence of VFD parameters on voltage stresses in low voltage windings

Currently the frequency control is widely used to provide high level of induction motors efficiency. Studies show that typical for the variable frequency drive (VFD) severe electro-thermal stresses influencing on the windings insulation negatively affect the windings reliability. The need to thoroughly study the impact of influencing factors and to develop possible ways to minimize this impact stipulates the relevance of conducted research. In this paper the influence of the VFD parameters on the level of voltage stresses affecting the insulation of low-voltage induction motor windings is studied. The study of nature and magnitude of electrical stresses was carried out by building a simulation model in the graphical programming environment Matlab Simulink. The modelling results are presented and the main findings are discussed in this paper.