Investigation on switching capability of bridge structures within power electromagnetic relays

Bridge structures, together with magnetic blowing components are frequently used in power relays or contactors for switching heavy DC load. However, the asynchronous mechanical separation of double or multiple contact pairs in series makes the arc interruption behavior more complex. In order to improve the switching capability of power electromagnetic relay, effects of contact force and magnetic field strength for blowing arc on electrical lifetime are investigated separately. During the electrical endurance experiments, the contact current and contact voltage waveforms are recorded explicitly, and the featured parameters which could characterize the degradation process of relay are recorded and analyzed, and then the failure modes and incentives are presented.