Evaluation Method Of Transformer's Ability To Withstand Short-circuit Current Based On Finite Element Analy Sis

The transformer is the core equipment of the power system,which guarantees the operation safety of the power system.The evaluation of the short-circuit current electrodynamic tolerance of the transformer can predict the winding deformation in advance,which provides a useful reference for the operation and maintenance of the power department.Therefore,on the basis of reading a large number of documents,a method for checking the electromechanical capacity of the transformer based on finite element analysis to withstand the cumulative short-circuit current is proposed.Firstly,the distribution model of leakage magnetic field under short-circuit current is studied.On this basis,the relationship of winding deformation between leakage magnetic field and short circuit currerlt is analyzed.The influence factors of leakage magnetic field and short circuit current are analyzed.Based on the markov state transition algorithm,the cumulative effect model of multiple short circuit currrents on transformer winding deformation is constructed.Therefore,the checking method and process of the transformer's resistance to cumulative short circuit current are put forward.Secondly,an electrodynamic deformation model of transformer winding short circuit current considering the mechanical stress effect of transformer winding was established in COMSOL software.Analyze the influence of various factors in the simulation.The dynamic deformation of transformer wining under different shor-circuit conditions is simulatedd.The deformation law of the transformer winding short circuit current is obtained.Finally,the prediction model of accumulated deformation tolerance of transformer windings is constructed by using markov state transition algorithm.The transformer is checked and analyzed with the actual network parameters.Verify the method of the paper.The research results of the thesis can provide useful reference for electric power maintenance personnel to grasp the transformer's electrodynamic tolerance in advance.