Thermal Field Simulation and Analysis of Tulip Contact Based on Virtual Material Method

Abstract

In order to analyze the temperature distribution of circuit breaker tulip contact, a thermal field simulation model for tulip contact is built combined with the electromagnetic-stress-thermal coupled finite element simulation and virtual material method which models the contact resistance characteristics of tulip contact. The temperature rise characteristic of tulip contacts under rated current conditions and short-circuit conditions is analyzed with the model. Results show that the virtual material method can describe the contraction resistance and additional resistance at the end of the contact finger simultaneously, so as to simulate the partial high temperature of the contact interface. Then, the influence of spring pressure and pressure uniformity on the thermal field of tulip contact is analyzed. Results show that the decrease of spring pressure and the imbalance of contact finger pressure may lead to an increase in the temperature rise of the tulip contact. The proposed method can be used as a reference for the design and the overheating analysis of tulip contact.

Analysis and Optimization of Contact Material Ablation under the Cumulative Effect of the Number of Breakings of OLTC

“…Since the contact resistance constitutes a significant proportion of the circuit resistance within the interrupter chamber, the temperature rise in OLTC is significantly influenced. Contact resistance is composed of both shrinkage resistance and surface film resistance, with the value of the surface film resistance experiencing an increase [ 21 , 22 ]. The formula for calculating the surface film resistivity is as follows: …”