606 / 2022-03-30 18:25:15

Experimental study on the effect of trace elements in copper-chromium contacts on the current cut-off level of vacuum switches

vacuum switch; contact material; copper-chromium contacts; trace elements; current cut-off level

The cut-off phenomenon of vacuum switch will produce high overvoltage in the electrical circuit, which threatens the safety and insulation of electrical equipment. Adding trace elements to the contact material is one of the important measures to reduce the cut-off level of vacuum switch. In this paper, the trace element Te (tellurium) is added to CuCr (copper-chromium) contacts as the research background, and the oscillating circuit and detachable vacuum interrupter are used to measure the cutoff value of CuCrTe contacts with different additions and different processing techniques. The experimental research The influence of trace element Te on the cut-off value of CuCr contacts, and the contact material composition and process with low cut-off value characteristics are sought. According to the statistical data of multiple sets of interception obtained from the experiment, it is preliminarily proved that the improvement of the contact material can affect the level of the interception value. The results show that adding Te element to the CuCr contact can reduce the material's cut-off value. With the increase of the Te element content in the contact, the cut-off value decreases unidirectionally, and the high-frequency oscillation of the arc voltage and current near the cut-off moment is more pronounced. Obviously, it indicates the threat of back-arc heavy breakdown. The experimental results can provide a reference for the comprehensive optimization of copper-chromium contact trace element addition and switch performance indicators.