3-D finite element analysis of magnetic force on the arc for arc chamber design of molded case circuit breaker^*

¹ Dept. of Electrical Engineering, Chungbuk National University, Korea
² Dept. of Industrial Safety Engineering, Chungcheong College, Korea

Corresponding author: kjlim@trut.chungbuk.ac.kr

Received: 11 May 2000
Revised: 9 March 2001
Accepted: 9 March 2001
Published online: 15 June 2001

Abstract

It is necessary for the optimum design of arc quenching chamber in the molded case circuit breakers to analyze magnetic force acting on the arc in the chamber. The magnetic blowout forces and the distribution of magnetic field induced by arc current depend on the shape, arrangement, and kinds of material of grids in the chamber. The effective method to design V-slotted iron grid in the arc quenching chamber is discussed in this paper. The magnetic blowout force and flux density were obtained by using the 3-D finite element method considering non-linearity of iron grids. The grid model designed optimally was also verified by means of the interruption performances test. It is shown that our design method is a useful tool for design of arc quenching chamber in the circuit breakers.