Research on integrated design of vacuum switch based on permanent magnetic actuator for hybrid DC contactor

This paper focused on a fast mechanical switch applied in 2kV hybrid DC contactor. An integrated design of vacuum switch based on Permanent Magnetic Actuator (PMA) is proposed. The stainless steel bellows is removed to avoid vacuum failure caused by air leakage and eliminate restriction of bellows' fatigue life compared to conventional vacuum switch. Both monostable structure and compact springs' position contribute to achieve smaller size. And an enclosure vacuumized inside covers the entire actuator including contact parts. Thus, a mechanical switch with strong compactness, high reliability and low maintenance is obtained. FEA and multibody dynamics analysis methods are applied to analyze static and dynamic characteristics of the PMA. Mechanical strength analysis demonstrates that integrated vacuum encapsulation is able to withstand the impact force derived from fast operation. The study results prove that proposed mechanical switch satisfies requirement of a 2kV hybrid DC contactor and has reliable structure.