In view of such phenomenon as serious heat and excessive temperature rise of T2Y self-propelled contact finger for a circuit breaker during the temperature-raise test

the performance of raw materials for the contact finger is tested and studied. At the same time

the structure of the T2Y self-propelled contact finger is simulated and optimized in combination with the actual service condition of the contact finer. The simulation results show that under the same service condition the maximum elastic deformation of the contact finger after structure optimization is de-creased from 0.126 mm before optimization to 0.045 mm

and the maximum equivalent stress is decreased from 175.56 MPa to 72.74 MPa

which is reduced by 64.7% and 58.6% respectively than that before optimization. The experimental verification results show that the gripping force of CuCr1Zr contact after 10 000 mechanical endurance tests is approximately 16.35 N

which is about 34.46% higher than 12.16 N of T2Y. This effectively avoids the distortion of electric field across open contacts and decrease of breaking performance due to insufficient gripping force during the service of the contact. At the same time

it together with the circuit breaker successfully passed the 6 300 A×1.1 times temperature rise test.