Detection And Research On The Switchboard’s Internal Insulation Fault

At present, domestic method of detecting the insulation fault is relatively single, lacking of meansand theoretical basis for on-line monitoring. It can not provide timely, qualitative and designatedoverhaul and clearing of the insulation fault, which severely affects the safe, effective and reliableoperation of electrical equipments.This thesis introduces the TEV (Transient Earth Voltage) method of non-intrusive dischargingactivities, a method that mainly collects the signal of transient voltage through coupling capacitancesensor to detect the discharing status and monitor the fault location of electrical equipments. By testingthe transient voltage induced from the earthing inductor of the operating equipment of electirc powersystem, the TEV method has a broad application prospect in insulation fault testing technology.In the thesis, several typical fault simulation tests are applied to conclude the flaw feature ofdifferent kinds of faults. The establishment of corresponding database, qualitative and designatedoverhaul and the degree of the insulation faults comparing with the data, together provide the testingmethod and judging basis for the fault maintanance operator. Meanwhile, through the simulation of theelectirc field within the switchgear, tests are focused on the electrical parts that are vulnerable to partialdischarge in high voltage electric field.In the end, specific examples of real-time detection in the spot of switchgear are given to analyzethe detection and location of the insulation fault. The application of this technique in the practicalengineering has a great significance in judging and clearing of the insulation fault as well as ensuringthe safe and stable operation of the power network.