Thermal Analysis of AC Contactor Using Thermal Network Finite Difference Analysis Method

To predict the thermal behavior of switchgear quickly, the Thermal Network Finite Difference Analysis method (TNFDA) is adopted in thermal analysis of AC contactor in the paper. The thermal network model is built with nodes, thermal resistors and heat generators, and it is solved using finite difference method (FDM). The main circuit and the control system are connected by thermal resistors network, which solves the problem of multi-sources interaction in the application of TNFDA. The temperature of conducting wires is calculated according to the heat transfer process and the fundamental equations of thermal conduction. It provides a method to solve the problem of boundary conditions in applying the TNFDA. The comparison between the results of TNFDA and measurements shows the feasibility and practicability of the method.

[1]  J. Paulke,et al.  Thermal simulation of switchgear , 2001 .

[2]  H. Weichert,et al.  Advanced thermal simulation of a circuit breaker , 2004, Proceedings of the 50th IEEE Holm Conference on Electrical Contacts and the 22nd International Conference on Electrical Contacts Electrical Contacts, 2004..

[3]  Bor-Jenq Wang,et al.  Thermal modeling of electrical contacts in switches and relays , 1995, Electrical Contacts - 1995. Proceedings of the Forty-First IEEE Holm Conference on Electrical Contacts.

[4]  Leroy S. Fletcher,et al.  Recent Developments in Contact Conductance Heat Transfer , 1988 .

[5]  Yoshihiro Kawase,et al.  Heat analysis of thermal overload relays using 3-D finite element method , 1999 .