Spectrum of Induction Machine Stator Currents, Affected By Clutch Wobbling and Mixed Eccentricity

Abstract

Current spectrum of a four pole-pairs, 550 kW, induction machine were calculated for the cases of full symmetry, clutch wobbling, static and mixed (static + dynamic) eccentricity. The calculations involve integration of 93 electrical plus four mechanical ordinary differential equations. Electrical equations account for variable inductances affected by slotting and eccentricities. The calculations were followed by Fourier analysis of the stator currents in steady state operation. Zooms of the current spectrums, around the 50 Hz fundamental harmonic as well as of the main slot harmonic zone, of both calculated and measured currents are included.