Research On Intelligent On-line Monitoring System Of Switchgear’s Partial Discharge And Design Of Its Sensor

With the grid scale increasing, our demand for the safe and reliable operation of powersystem is gradually higher. Due to the relative lack of maintenance personnel, the way ofmaintenance requires to change over time and need. Centralized monitoring and maintenanceof big run, overhaul mode is a general trend. In order to achieve centralized monitoring of alllevels substations, it’s sacrificed to obtain the switchgear insulator message online in allsubstations, so switchgear partial discharge monitoring is very important.The title combined UV（ultraviolet） Law UHF（ultrahigh frequency） method and thetemperature rise measured three techniques to monitor the occurrence of partial dischargeswitchgear. The combined technology not only plays their respective advantages, but also theadvantages and disadvantages of complementary. Joint technical design-based sensors have thecharacters of low power consumption, high reliability, high sensitivity, good linearity, easy toinstall and cost low cost. On this basis, we developed a set of switchgear partial dischargeintelligent on-line monitoring system scheme. It consists of three parts, respectively is thesensor nodes, the data receiver and the server terminal. The system uses ZigBee wirelesscommunication technology, network automatically, can accommodate up to216sensor nodes,suitable for numerous features of the substation switchgear. The data receiver responsible forthe wireless collection of data, and then forwarded to the server terminal cache. The serverintuitively display discharge data and waveform, and achieve abnormal alarm by installingspecialized partial discharge monitoring software. The server is connected to the externalnetwork, eventually achieve remote intelligent, real-time, dynamic monitoring of partialdischarge switchgear happening.The article do the simulation for partial discharge UV radiation characteristics and UHFswitch cabinet propagation characteristics and provide technical support for UV and UHFswitchgear partial discharge detection. The final design of the switch cabinet typical dischargemodel set up switchgear partial discharge detection system. The scene practice thecommissioning test for the new sensor design. Experimental result shows that: the sensor cansensitively detect the UHF and UV by the needle-plate corona discharge. Needle platespacing is constant, the higher the applied voltage, the discharge is more obvious. Under thesame voltage level, the smaller the pitch, the worse the electrical strength, the lower thebreakdown voltage, the more prone to discharge. With the detection distance increasing,measured UV pulse presents certain pulse linearity, the reduction in the number of UHF pulse;indicate the attenuation of UHF electromagnetic waves in the dissemination process.