Improve the electrical life of the main contacts to improve AC contactor has become the key to the whole life

AC contactor is a wide range of large electrical switches, its performance not only has a direct economic interest , but also to the power system power quality and energy resources. With the adoption of new  power transformers , new technology , AC contactor mechanical life has reached millions of times , and its electrical life is generally only about 10% of mechanical life . Improve the electrical life of the main contacts AC contactor has become to improve the overall life of the key. In particular, AC  mcb circuit breaker category AC-4 , the contact erosion occurs mainly in the closing process , which ac contactor made ​​more stringent technical requirements. This requires AC contactor entire process to achieve optimal control, reduce contact collisions, while achieving arc minutes without closing , reducing the arc erosion ;  air circuit breaker  to power shortage of resources , contacts made ​​on the traditional energy-saving operation requirements. In this paper, the above requirements, carry out exchanges and contacts without arc of intelligent technology. The first rebound of the contacts of the mechanism , and the DC excitation AC excitation contrast different characteristics , given the lack of AC and DC excitation excitation advantages , combined with a large test to determine the optimum excitation of the DC excitation voltage , and on this basis, , combined with the existing DC excitation control mode , this paper proposes AC contactor multistage excitation system regulator DC pulse excitation control mode.