Combined analytical and finite element modeling for negative sequence studies in salient pole synchronous machines

A new software package called WAVE has been developed by the author´s company in collaboration with the University of Alberta, Canada to calculate the airgap flux density from MMF and permeance functions in salient pole synchronous machines. The permeance functions are derived from the magnetostatic finite element analysis using linear steel properties. Negative sequence rotor heating effects have been studied using the new software tool. The calculated currents in the amortisseur bars show good correlation with measured currents for a synchronous machine with phase-phase short circuit. The fractional slot machines requiring a large number of pole pitches for field solution by time-stepping finite element analysis can be analyzed with the new software tool with very low computational resources.