Analysis of test current and contact opening speed influence on dynamic resistance tests on circuit breakers

The dynamic resistance measurement (DRM) has been highlighted as an efficient technique to analyse the operative state of circuit breakers by evaluating the degradation level of their main and arcing contacts. However, it still leaves room for improvement. In this paper, an analysis of the result reproducibility of DRM tests is presented, which was implemented with speed reduction of the contact opening process, as well as an analysis of the test current level influence on DRM results. To evaluate the methodology, a comparison was made using the coefficient of determination (R2) between the results of the DRM tests carried out with speed reduction and at rated speed. To perform the tests, an alternative system was adopted, which consists of a digital oscilloscope, a stationary battery,…