Risk Assessment Based on Ion Current Measurement on a DC-GIL with Metal Particles

Metal particles pose the most significant risk for the occurrence of a breakdown in a DC-gas insulated line (GIL). To gain a reliable prognosis, this study presents a method of risk assessment based on the ion current measurement (ICM) on a DC-GIL. Therefore, the authors develop a risk assessment model based on the ion current's characteristics derived from measurements. The measurements respect different metal particles varying in shape, size, and material. The results show that the ion current depends on the number of particles, their shapes, and the location of the particles. After evaluating the ICM as a diagnosis method for DC, the method enables risk assessment for DC-GIL and therefore, maintenance planning.