Particle-Triggered Corona Discharge Characteristics in Air Insulation Under DC Voltage

Under a dc stress, a wire particle within gas insulation will exhibit complex motion behavior, leading to more challenges to detect its existence. Therefore, this work deals with an investigation of corona discharge characteristics generated from a wire particle with different particle positions in an air gap. Three different wire particles are prepared in this investigation. The particle is placed between parallel-plane electrodes with a fixed gap of 20 mm. Five different positions are evaluated to study the partial discharge (PD) behavior generated from the wire particle. The exponential probability distribution is used to evaluate the pulse occurrences from different positions. Pulse sequence analysis (PSA) technique is employed, and an interpretation algorithm is introduced to understand the discharge pattern. The results show that each of the particle positions creates a unique pattern, which discharge mechanism behind the pattern is explained. From the pattern observation, a wire particle has single cluster of corona type as attached to the electrode while multiclusters are found when it is floating in the gap. Moreover, it is also found that different particle lengths are also affecting the discharge pattern characteristic.