Causes Analysis and Suppression Measures of Corona Discharge in Nanchong 500 kV Substation

In order to mitigate the serious corona discharges in Nanchong 500kV substation,we established a simulation model by the COMSOL Multiphysics software based on FEM to investigate the corona in the area,and believed that the serious discharge was caused from the facts that complex electrical wiring,wire arrangement and other factors were not taken into account when selecting shielding rings and the superposition of electric field generated by conductors around the door-type tower.Many countermeasures,such as to optimize geometric parameters of shield rings,to adjust the connection mode,and to change the phase sequence,were used to eliminate the serious corona discharges.It is revealed that optimizing geometric parameters of shield rings,and adjusting connection mode or changing phase sequence need to change the existing electric connection,which is hard to apply,but it can be used as reference for future project design.