On-line monitoring of partial discharges and pollution leakage current in substations

摘要

This paper reports laboratory development and field trials of two on-line condition-monitoring systems for high voltage power equipment. The first system is for on-line measurement of partial discharges and for the evaluation of their parameters. The principle used utilizes capturing partial discharges by means of a current transducer (Rogowski coil), fibre-optic transmission link and fast computerized wide-band data acquisition system. The second condition monitoring system is for continuous on-line measurement and recording of the surface leakage current on polluted insulators of high voltage equipment. A signal proportional to the leakage current is fed into a sensor the output of which is transmitted via a fibre-optic link to the data acquisition system. This system enables continuous recording of the RMS value of the leakage current. Both partial discharges and pollution monitoring systems were tested for six months in a high voltage substation where the computerized data acquisition equipment was placed in the control room. These relatively low-cost placed in the control room. These relatively low-cost systems proved to be reliable, robust and safe to use under the harsh environmental and electromagnetic conditions in HV substations.