Because the large-current switch-gear can hardly reach the standard on temperature rise under the natural convection heat dissipation condition

forced convection heat dissipation is applied. In order to study the influence of the forced convection on the temperature rise

the temperature rise distribution in the switch-gear is analyzed by establishing a multi-physics model

and the switch-gear simulation model is verified by experiments. Different fan number and fan faults are set to study the temperature distribution in switch-gear with different heat dissipation conditions. It is found that the temperature rise exceeds the requirements of GB/T 11022—2011 without forced convection heat dissipation

and the highest temperature position locates at joint position between moving and fixed contacts. The fans at cable chamber and breaker chamber are important for lowering the temperature

and their function is proved to be independent. Compared with a single fan

two or three sets of fans perform more effective heat dissipation effect. However

the heat dissipation effect is similar when applying two or three set of fans. Therefore

applying two sets of fans in switch-gear is more energy-efficient.