Distribution of Electric Field for EMU's Post Insulators Based on the Finite Element Method

Abstract

Compared with power system, post insulators used in High-speed Electric Multiple Unit (EMU) have unique features such as limited space, low number of sheds and complex pantograph, which produces high electric field at some part of post insulators. When the insulators electric field exceeds a numerical value, it will produce corona discharge and reduce the reliability of High-speed EMU. At the same time, a distinct discharge phenomenon has been observed on the surface of the small curvature radius for pantograph. For guiding optimization of electric field for post insulators and pantograph, a simplified model of post insulators as well as the pantograph is established to calculate the distribution of potential and electric field based on ANSYS. Because the applied voltage cycle is far less than the relaxation time of the dielectric, electrostatic field module can be used in the ANSYS Simulation. By simulating, the maximum electric field is occurred at the pantograph angle and some measures should be taken to reduce the electric field to assure the reliability of the EMU. The potential would decrease along the axis of the post insulator and the first umbrella bear the largest voltage drop.