Study of the degradation process of rolling contact connector with fractal rough surfaces

Rolling Contact Connector (RCC) is a new technology utilized in high performance electric power transfer systems with one or more rotating interfaces, such as radars, satellites, wind generators, etc. Rolling contacts components are used in the RCC instead of traditional sliding contact to transfer electrical power and/or signal. Since the requirement of the power transmission increasing in these years, the rolling electrical contact characteristics become more and more important for the long-life design of RCC. In this paper, a RCC prototype with a novel rolling contact structure is presented. Experimental investigation is carried out to study the degradation process of the rolling electrical contact characteristics during its life-Time. Scanning electron microscope and confocal laser scanning microscope are utilized to obtain the gradual changes of the microscopic morphology and elemental composition on the contact surfaces. An electrical contact resistance theory based on fractal geometry is introduced to describe the contact behavior of RCC which is found with typical fractal features. Numerical analysis results illustrate the dependence of the electrical contact properties on the fractal parameters. The mechanism of rolling electrical contact degradation is discussed in detail.