Hybrid Sensing of Partial Discharge Faults in Air Insulated Switchgear

Partial discharge measurement has proven to be one of the most reliable sources of information about the health of electrical power equipment. The significant benefits of online condition monitoring and pre-emptive detection of partial discharge faults are quite well known since the last decade. The objective of this research is to develop new advanced sensor technologies that are cost effective, reliable and efficient for early detection of PD measurements in air insulated switchgear, in the range of medium voltage (MV) or low voltage (LV). This paper includes testing of these sensors and their performance evaluation under a certain number of partial discharge faults. Three sensors were developed and tested by the authors over a number of years, which include high frequency E-field (D-dot) sensor, Rogowski coil and loop antenna sensor. Among these three sensors, it is proven than the first two are more dependable when it comes to the PD measurements due to their high signal to noise ratio. These sensors are cost effective, non-intrusive and can be customized according to the nature of faults and type of equipment to be tested. Moreover, many of such sensors can be connected together with one data acquisition device.