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Degui CHEN Xingwen LI Ruicheng DAI
In order to understand the recovery characteristics of AC contactors and improve their performance, experimental measurements were used to investigate the arcing gap recovery process including dielectric recovery strength and reignition, to a pair of splitter plate together and four kinds of arc chamber of AC contactors. A special circuit was designed to perform the work. It demonstrates that under lower current, the dielectric recovery strengths of all kinds of arc chambers in the paper have no significant difference. However, with the increase of current, the difference of dielectric recovery strengths of them is much clear. The reignition characteristics of a pair of splitter plate and arc chambers are similar. With different configurations of arc chambers and prospective currents, the forms of post current zero reignition are distinct.
Xingwen LI Degui CHEN Zhipeng LI Weixiong TONG
In the optimum design of AC contactors, it is necessary to analyze the dynamic behavior. Moreover, movable contacts and core bounce have remarkable effect on the lifetime of contactors. A set of differential equations describes the coupling of the electric circuit, electromagnetic field and mechanical system taking account into bounce and the influence of friction. With virtual prototyping technology, the dynamic behavior, especially for contacts bounce, has been investigated according to different electrical circuit parameters. Two approaches are introduced to solve electromagnetic parameters. Based on 3D finite element static nonlinear analysis, the flux linkage and electromagnetic force can be evaluated with different air gap and exciting current for larger gap. In addition, concerning to the shading coil for smaller gap, magnetic circuit can facilitate the calculation. The validity of the proposed method is confirmed by experiments.