Study on Influence of Contact Structure on Phase Shift Time of Magnetic Field in Vacuum Under Various Current Frequencies

The purpose of this article is to identify the influence of the contact structure on the phase shift time (PST) of the magnetic field in vacuum under various current frequencies. In the paper, the PST of six different contacts was compared, including three structures of axial magnetic field (AMF) contacts and three structures of transverse magnetic field (TMF) contacts. The results signify that the PST of the TMF contacts is much smaller than that of the AMF contacts, which all decreased with increasing current frequency. Moreover, for TMF contact, the PST of the cup-type TMF contact was the smallest, followed by the swastika shaped TMF contact and the helical TMF contact, ranged from 21.0 μs to 0.75 μs. For AMF contact, the PST ranged from 1.47 ms to 0.13 ms. The PST of cup-type AMF contact with iron core is the smallest, under the frequency over than 300 Hz. The PST of the 2/3 turn coil-type AMF contact is the smallest under the frequency less than 100Hz.