800 kV滤波器用断路器合闸电阻电热力多场耦合下性能评估OA

The closing resistor plays an important role in suppressing the overvoltage and closing inrush current of fil-ter bank circuit breakers.However,with the increase in voltage,the failure rate of the closing resistor in 800 kV filter circuit breakers significantly rises.Currently,multi-field coupling simulations for the working environment of the clos-ing resistor are insufficient,and corresponding improvement measures have not been verified.In this paper various possible failure causes of closing resistor in filter circuit breakers are simulated and analyzed.The corresponding im-provement solutions are proposed and the improvement effectiveness is verified by simulation.The results show that under normal conditions the closing resitor is normal in electric field distribution and stable in operation.However,in case of abnormal conditions,local temperatures rise rapidly,potentially leading to concentrated thermal stress and af-fecting its performance.The common faults include the attachment of metal foreign objects to the surface of the resis-tor,wek coaxiality of the resistor disc and weak contact at the end faces.To address these issues,several optimization measures are proposed,namely,adding aluminum sheets between resistor disc to improve weak contact at the contact surfaces;adding aluminum blocks to the end resistor blocks to reduce stress concentration at the ends;and increas-ing the external surface diameter of insulation support and the outer sheath of the closing resistor stack to enhance the coaxiality of the resistor disc,thereby reducing electric field distortion and improving overall protection.Simula-tion results show that these optimization measures significantly enhance the performance of the closing resistor,reduce temperature rise and thermal stress and improve its safety and reliability,which are of significant importance for the simulation analysis and optimization design of closing resistor.