No-load voltage waveform optimization and damper bars heat reduction of tubular hydro-generator by adjusting damper bar pitch and skewing stator slot

Improvement of no-load voltage waveform and optimization of damper bars loss and heat are important problems for designing tubular generators and ensuring operation reliability of the generators and electric network. The no-load voltage waveforms of a 30MW tubular hydro-generator are optimized and the damper bars heat are reduced with the design scheme which adjust damper bar pitch and skew stator slots, and the computations are implemented and analyzed by multi-slice moving electromagnetic field-circuit coupling model of the hydro-generator and 3D temperature field FE model of the rotor. The results show that the waveforms of the no-load voltage are improved observably and the temperature of damper bars are reduced observably when reasonable increasing damper bars pitch and skewing stator slots. The calculation results are coincident well with the test data. The research is helpful for improving design standard and enhancing the operation reliability of the large hydro-generator and electric network.