Examination of the partial discharge activity of medium voltage insulators during the tracking wheel test

The tracking wheel method is an elaborate technique for evaluating the quality of non-ceramic insulators. Although it is not required by European standards, there is an interest in its application due to recent problems with the quality of these products. Despite the undeniable long-term positive effects, some utilities consider this method time consuming and expensive, especially when the products of numerous manufacturers are to be evaluated, or when the test is aimed to be performed frequently as sampling tests. This article presents partial discharge measurements performed during a complete cycle of the tracking wheel test. Various evaluation methods are investigated in order to find features that may be able to indicate the possibility of a failed test even at a lower number of cycles.