Comparison of partial discharge characteristics for different defect types in SF<inf>6</inf> gas insulation system

Abstract

The high reliability, less maintenance and compact size of Gas Insulated Switchgears (GISs) have made them the primary choice for many utilities. However, sometimes insulation defects inside GIS can be a serious threat to safe operation of GIS and can lead to costly disruption of supply. As insulation failure usually starts with partial discharge (PD) activity, this paper investigates the differences in PD characteristics in SF 6 gas among different types of defects. The defect types considered in this study are particles in a gas gap, particles adhered on a spacer surface and spacer/electrode detachment. Different experiments were made for sequential PD measurements using the system of PD-Current Pulse Waveform Analysis (PD-CPWA). The PD phase characteristics, PD pulse number and PD current were analyzed for the different defect types. Also the ratio of voltage increment to phase increment at the next PD pulse appearance (∆u/∆φ pattern) was obtained and compared for each defect type. Experimental results show that correct identification of defects can be achieved based on considered PD characteristics.

Towards Secured Online Monitoring for Digitalized GIS Against Cyber-Attacks Based on IoT and Machine Learning

“…Regarding the number of PD pulses, it requires statistical calculations for PD events. Instead, it is proposed in this paper to use pulse sequence features including phase appearance and voltage magnitude, which proved in previous researches their effectiveness in PD diagnosis [46], [47]. In addition, these pulse sequence features can be easily acquired using voltage sensors making them suitable to be used with IoT architecture.…”

3D Printing Technique-Improved Phase-Sensitive OTDR for Breakdown Discharge Detection of Gas-Insulated Switchgear

“…High-voltage (HV) cable and gas insulated switchgear (GIS) are the part and parcel of HV power supply and transmission system whilst their health structure monitoring is always vital for the HV power system [1]. The unavoidable insulation defects in the HV equipment generated during manufacturing, transportation, installation, or operation can lead to insulation degradation [2,3], resulting in partial discharge (PD) which then accelerates and intensifies the insulation failure. The insulation failure eventually leads to the breakdown discharge of the HV equipment, which will cause severe damage to the insulation and crash down the power supply and transmission system.…”