Abstract: As the number of contact fingers of a high-capacity grounding switch is large,and the structure of static contact is complex,the conventional analytical method can not carry out accurate calculation in the case of the peak current.In this paper,the finite element method is used to establish the model for the complex case.The simulation method is used to analyze the current distribution on each finger.Combined with the formula,the electrodynamic force acting on the connection between the contact finger and the fixed contact is calculated,which is used as the design basis of the contact pressure of the touch finger spring,and verified by the test.

Key words: high-capacity earth switch, finite element, electrodynamic force, contact finger, peak current