Condition assessment of arc contacts through dynamic resistance measurement (DRM) and wavelet analysis

Abstract

Circuit Breakers constitute one of the main electromechanical components of a power grid, playing an essential role in protecting other network components such as transformers and generators. Throughout their lifetimes, CBs experience thermal and mechanical stresses and other factors. The operation of CBs under short-circuit currents or the high number of times of performance at a fraction of short-circuit currents can lead to gradual deterioration of the inner parts of the interruption chamber such as the main and arc contacts. Dynamic resistance measurement test is an effective method to assess the condition of contacts in CBs. This paper attempted to examine the effect of erosion in moving arc contacts through analysis of dynamic strength properties measured from a real 24 kV gas CB. This paper involved the essential characteristics for assessing the condition of arc contacts in a CB through wavelet analysis and the prediction of erosion in arc contacts.