Multi-physical field simulation and experiment of temperature-rise characteristics of switchgear compartment

The compartments usually operate at the reduced-current mode due to the limitation of the temperature rise. We investigated the heat generation and dissipation mechanism of a compartment, and tried to improve the heat dissipation capacity by installing fans. Firstly, Ansys E-mag and CFX were used to develop the electro-magnetic-heat-flow coupled model for the compartment with and without fans. The distributions of heat generation, air velocity, and temperature-rise were obtained. Then the calculated results were validated by the relevant tests. Finally, based on the calculation model,the thermal performance of the compartment with fans were investigated. It is found that the upper terminals of the incoming circuit breaker are beyond the limitation of the temperature-rise in the absence of fans. The recirculation can be clearly observed near outlets, which has negative effects on the elimination of the heat gas. The thermal performance of the compartment can be improved by installing fans at the outlets. The average temperature rise of the upper terminals will be decreased by 28.6% and 42.1%, when the air velocity of fans is 3 m/s and 6 m/s, respectively.