Abstract:

Based on the extensive engineering experience,it is known that the reliability of the normally-closed contacts of high-power transfer contactors is lower than that of the normally-open contacts.The adhesion of the normally-closed contacts is an important cause of the failure of high-power transfer contactors.Firstly,taking the high-power transfer contactor as a research object,the fault tree analysis is carried out in accordance with the problems encountered during the testing.It is determined that the poor weld-resistance performance of the contact material and insufficient electromagnetic attraction force are the main causes of the adhesion failure of the contacts of high-power transfer contactors.Subsequently,by replacing the contact material and optimizing the processing methods,the weld-resistance performance of the contacts is enhanced.Meanwhile,the design of the electromagnetic system is optimized to reduce the magnetic gap and increase the electromagnetic attraction force.Finally,the life test and other verifications are conducted on the samples with the optimized solutions.The test results show that the optimized solutions are effective and solve the problem of the adhesion of the normally-closed contacts of high-power transfer contactors.

Key words: high-power transfer contactor, contact adhesion, weld-resistant performance, electromagnetic attraction force