Researching on the rotor slot pitches selection rule of half-speed turbo generator based on equivalent load impedance method

A method for simulating the single machine rated operating state of turbo generator by imposing equivalent load impedance on each phase winding in Ansoft external circuit is proposed. The correctness of equivalent load impedance method is proved through the comparison between calculated value and designed value of generator parameters including phase voltage, current and power factor in case of a 1,000MW level half-speed turbo generator prototype. The synchronous reactance, voltage waveform and excitation current in the condition of different rotor slot pitches are obtained by using this method. The rotor slot pitches selection rule of half-speed turbo generator is researched through analyzing the variation regularity of synchronous reactance, voltage waveform and excitation current.