Poor contacting of circuit breaker handcart contact will result in overheating of contact

or even lead to ac-cident of power grid. A 3-D finite element model based on the coupled field theory to calculate the temperature risein circuit breaker handcart contact is built. The model is adopted for stress field calculating in different cases

andanalyzing the influences of static contact insertion depth and offset angle on contact pressure. And the insertion depthexperiment is carried out. It is concluded that the insufficient insertion depth led to increasing contact resistance ofplum blossom contact is the main cause of overheating faults in circuit breaker handcart contact. Then the steady tem-perature

current density and stress distribution of circuit breaker handcart contact to carry rated current when staticcontact insertion depth is 1/2 are calculated and analyzed. Finally

the contrast temperature rise experimental plat-form of plum blossom contact with memory alloy tablets and plum blossom contact with common tablets is set up. Theresults show that the memory alloy tablets is helpful to reduce the temperature rise of the plum blossom contact

it can effectively reduce the overheat fault.