Optimization Of No-load Voltage Waveform And Damper Winding Loss And Heat Of Tubular Hydro-generator Based On Comparative Analysis Of Rotor Excitation Power Supply Models

Tubular hydro-generator is the best model for developing and utilizing low water head river and tidal energy resources.However,due to the narrow and long inner space of the generator,it is very difficult to build the electromagnetic model.Once improper,it is likely to cause overheated damage of damper bar,deterioration of no-load voltage waveform and other fault.Therefore,the modeling and analysis of electromagnetic field and temperature field have higher requirements.At the same time,in the modeling of hydro-generator,the influence of the selection of rotor excitation power source on the quality of no-load voltage waveform and the accuracy,rationality and solving efficiency of the analysis of damper winding loss and heat,has been rarely studied in public reports up to now.In view of this,this article has carried out the following research work based on the theory of electric motor electromagnetic field and temperature field:Firstly,on the basis of constructing the two-dimensional pure field analysis model of the tubular hydro-generator,the quasi-three-dimensional electromagnetic field-circuit coupling analysis model and the magnetic pole three-dimensional temperature field analysis model,the influence of current source in the field-circuit coupled model,voltage source in the field-circuit coupled model and exciting current density directly applied in the pure field model on the no-load voltage waveform and the heating calculation result and solution efficiency of the damper winding loss are analyzed and studied,and then the rotor excitation power supply suitable for the follow-up study of this paper is selected.It provides a theoretical modeling basis for electromagnetic and temperature analysis.On this basis,the influence trend of stator skewed slot structure and pole shoe and damper winding center line shift structure on no-load voltage waveform quality and damper winding loss and heat of hydro-generator is discussed.The results show that: although the stator skewed 1 slot structure can better optimize the generator no-load voltage waveform,it will increase the loss of the generator damper bar and cause the uneven distribution of the loss of the damper winding and the stator core;However,the pole shoe and damper winding center line shift structure can not only reduce the loss of damper winding.At the same time,it will lead to the deterioration of no-load voltage waveform of fractional slot generator.The research work of this paper has direct and effective reference value for optimizing the power quality of tubular hydro-generator and avoiding rotor overheating fault.