Prediction of the No-Load Voltage Waveform of Laminated Salient-Pole Synchronous Generators

This paper presents a combined analytical and FEM method for prediction of the no-load voltage waveform of laminated salient-pole synchronous generators. The described method takes into account saturation effects as well as the damper bar currents due to the slot pulsation field. The method calculates first the damper bar currents and then includes them in the calculation of the no-load voltage. The combination of magnetostatic 2D finite element simulations for calculating the magnetic coupling between the machine windings and of an analytical resolution, results in a very precise prediction of the no-load voltage. At the same time simulation time is drastically reduced, compared to transient magnetic 2D finite element simulations. The method was verified on several examples, comparing the obtained results (damper bar currents and no-load voltage) to results obtained from transient magnetic finite element simulations and in one case to the measured no-load voltage. A tool, implementing this method, is currently used by one of our major industrial partners. It is planned to use this method for analysis of the effects of various rotor eccentricity conditions in salient-pole synchronous generators.