1Deputy Engineer, Gujarat Energy Transmission Corporation Ltd.
2Superintending Engineer, Gujarat Energy Transmission Corporation Ltd.
3Addl. Chief Engineer, Gujarat Energy Transmission Corporation Ltd.
Global industrialization & increasing population results in rise of demand for quality and uninterrupted power supply. For this, substation equipment has to be made more efficient & reliable to cope up with increasing demand. Nowadays, worldwide, most of the utilities are being switching over from Air Insulated Substation (AIS) to Gas Insulated Substation (GIS) due to its compact design and high level of reliability with shortage of geographical area especially in urban regions.
In developing stage of GIS technology, there was a belief that GIS is maintenance free. However, the return of experience indicates that GIS also needs thorough checks during manufacturing, pre- commissioning & post-commissioning activities. At times, it is required to attend the defects that occur due to manufacturing errors, commissioning errors or operational issues. In certain cases of failure of Gas Insulated Switchgear, long outage of several days which may last up to months with high repair cost. Also, it is difficult to check for any abnormal conditions being its encapsulated switchgear design. Hence, proper condition monitoring of GIS is necessary to protect equipment before total breakdown in power system.
As per surveys available in open source, it is found that most of the in-service failures in GIS are associated with defects in the insulation system. Hence On-line PD testing and diagnostic tools have attracted increased interest for application in dynamic condition monitoring of whole GIS equipment.
State utility has successfully commissioned 400/220/66kV Bhogat GIS substation near Jamnagar area of Gujarat with Online Partial Discharge Monitoring System (PDMS) to diagnose & predict healthiness of insulation system of complete GIS switchgear.
This paper covers various customized features, challenges faced during commissioning, benefits (with case studies) & insights gained during execution of state utility ’s first online PDMS System at 400/220/66kV Bhogat GIS substation for online condition monitoring of complete GIS.
Partial Discharge Monitoring System (PDMS), Phase Resolved Partial Discharge (PRPD), Ultra high frequency sensors, Optical Converter Unit (OCU), Radial Distribution Cabinet (RDC), Radial Control Cabinet (RCC)
