Green Gas for a Grid as An Eco-Friendly Alternative Insulation Gas to SF₆: From the Perspective of Partial Discharge Under AC

This paper deals with the characteristics of partial discharge (PD) in green gas for a grid (g3), which is thought to be a promising eco-friendly alternative to substitute SF6 used in electrical power facilities and to reduce the greenhouse effect. g3 gas with 4% NOVECTM 4710/96% CO2 was used and electrode systems including a protrusion on conductor (POC) and a protrusion on enclosure (POE) were fabricated to simulate PD in a gas-insulated structure. PD characteristics in terms of partial discharge inception voltage (PDIV), pulse parameters in time and frequency, and the phase-resolved partial discharge (PRPD) pattern in SF6 and g3 were compared. From the results, the PDIVs of g3 were 76%⁻81% of that of SF6 in the POC and were 78%⁻84% of that of SF6 in the POE, depending on the gas pressure. Rising time, pulse width, and relative amplitude in the frequency domain of PD pulses in g3 gas were greater than those in SF6. In addition, the PRPD patterns indicated that both the average apparent charge and pulse count of PD in g3 were higher compared with those in SF6. The results from this paper are expected to provide fundamental material for the green manufacturing of gas-insulated power apparatus