Low Power High-Speed Folding ADC based Partial Discharge Sensor for Wireless Fault Detection in Substations

Partial discharge is a well-established metric for conditionmonitoring and assessment of high-voltage plantequipment, such as switchgear, transformers andtransmission lines. Traditional techniques for the detectionof partial discharge pulses involve physical connection ofsensors to the device under observation, requiring separatesensors for each item of plant, which can be costly and timeconsuming. Wireless partial discharge measurementprovides an attractive alternative, since sensors canmonitor multiple items of plant simultaneously. However,direct sampling of the received UHF partial dischargepulse is unsuitable for a scalable wireless sensor network,due to the high cost and power consumption required forhigh-speed data conversion. A sensor is proposed thatutilizes a pipelined, sample-and-hold based, foldinganalogue to digital converter structure that features lowpower consumption when no signal is present, making itsuitable for low-power data conversion of radiometricpartial discharge. A proof of concept circuit has beendeveloped using discrete components to evaluate theperformance of the system with 8-bit resolution at 25MSa/s and 56 mW of power consumption.