Voltage-difference analysis, a tool for partial discharge source identification

The application of the discharge parameter `voltage difference between consecutive pulses´ is discussed as a physically based tool to identify the kinds of defects that cause partial discharges. Different kinds of model-defects are investigated and the `Δu_n(Δu_n-1)-pattern´ is introduced as a new pattern for a powerful classification of discharge sources. It is demonstrated that an identification mainly based on Δu provides reliable classification results especially in cases where the accumulated phase of occurrence distributions include the risk of misclassification. When applying discharge parameters derived from the pulse-sequence analysis, high recognition rates of the correct `defect-class´ and a reliable rejection of other defects can be obtained