Application Of On-line Partial Discharge Monitoring System For Gas Insulated Switchgear

At present, there are more and more GIS equipments were used in the Dongguan power system even the Guangdong power system which its voltage is 110kV and above.GIS equipments are gaining the favor of the power system because of its small footprint, high reliability and maintenance-free advantages. But, in fact GIS equipment accidents and failures occasionally happens. Failure is mainly due to processing, assembly, transportation and field installation. Also, component deterioration and operating displacement are the important factors in failure. There are more and more GIS equipments getting to the maintenance-free life, we have to face the pressing problem that how to assess the operational status of equipment and carry out the maintenance according to the status of equipment. GIS partial discharge monitoring can help to detect insulation defects in GIS, avoid insulation failure and improve the safe operation of the level of GIS. Also based on the GIS partial discharge monitoring, we can achieve the status of GIS insulation maintenance, reduce outage time and save the cost of maintenance.For the above, the main purpose of this project is to establish a GIS PD online monitoring and fault diagnosis system. The system uses the highest sensitivity and interference of the strongest partial discharge sensor. Under the condition of Normal operation on GIS and no need to open any part of it, the system can monitor the partial discharge and locate the defects. And it can detect the insulation defects early and determine the type of defects, the severity of defects and the trends of defects. Based on the monitoring on the running equipments, we can achieve the status of GIS insulation maintenance, reduce outage time and save the cost of maintenance, and achieve the long-term protection of GIS equipment.