Current-Carrying Performance Degradation Mechanisms of Outdoors Power Connectors Under External Vibrations

The environmental adaptability of outdoor power connectors exerts a crucial influence on the reliability of electrical systems. In this work, the current-carrying performance degradation of commercial power connectors under forced mechanical vibration conditions is investigated comprehensively. The variations in the instantaneous electrical contact resistance (ECR) of power connectors are accurately recorded in real time, and then effects of vibration amplitude, frequency, and load current on the ECR are interpreted explicitly. Furthermore, multi-cycle swept-sine vibration tests are carried out, and the open circuit failure of power connectors is reproduced. The continuous carrying of a heavy current combined with the mechanical fretting between socket and plug results in surface coating wear, debris melting, and the formation of copper oxide. The observed surface morphology and element contents support the presented failure mechanisms of power connectors under external vibrations.