A Novel Composite Sensor for Overvoltage and UHF Partial Discharge Measurement in GIS

The presence of overvoltage can cause the insulation deterioration and excite the partial discharges (PD) in gas-insulated switchgear (GIS), and it is necessary to detect the overvoltage and PDs simultaneously to evaluate the insulation performance. A novel GIS internal composite sensor for PD detection and overvoltage measurement is proposed in this paper. The proposed sensor is mainly formed with a disc-type monopole UHF sensor and an overvoltage sensor. The effectiveness and sensitivity of the sensor are tested on a designed platform under power frequency voltage, switching impulse, lightning impulse, and oscillating lightning impulse, respectively. Experiment results show that the proposed sensor can be used to detect overvoltage and UHF signals effectively and is expected to help in the GIS condition evaluation.