Gas-insulated switchgear (GIS) has developed rapidly and been applied in the high-voltage and ultra/extra-high-voltage transmission fields of the power supply system, with advantages such as immunity to environmental hazards, short construction and installation period, low construction cost, safe and reliable operation, immunity to wireless interference, and small land area. However, its joints often suffer problems such as uneven plating and plating peeling due to insufficient manufacturing technology and machining differences between manufacturers, causing poor contact at the contacts, excessive loop resistance, and serious heating even under normal current, inducing local overheating faults. For example, in a substation, the high-voltage disconnector had poor contact between the fixed and moving contacts, causing abnormal heating after current flow and contact burning. Contact temperature is the most direct indicator reflecting contact thermal fault information. Therefore, online monitoring of the contact temperature of GIS equipment is of great significance for the safe and stable operation of the power system.
Fiber optic temperature measurement technology has the advantages of immunity to interference signals, good insulation, high stability, small size, convenient installation and strong embeddability. The fiber optic temperature measurement system can adopt an embedded installation method, which can accurately and directly detect the temperature of the cable end cap without damaging the insulation of the cable end cap. The fluorescent fiber optic probe is directly cast in the silicone rubber sheath of the cable end cap, and the fiber connector is reserved. During on-site installation, the optical cable can be inserted directly into the reserved fiber connector to complete the connection. Meanwhile, this installation method is also convenient for wiring and can be laid together with the cable. The embedded method embeds the fiber optic sensor probe into the sheath during sheath manufacturing, which can not only ensure stable contact between the probe and the cable, but also complete insulation testing before shipment to ensure insulation performance.
The standalone flexible device has a built-in screen display, which can independently display alarm status, wet alarm valve settings, alarm record query, alarm handling (delete or save alarm records), password reset, etc. After the device is connected to the transmission network, the above operations can also be performed on the computer operating system platform. Data transmission does not interfere with local synchronous measurement and transmission: each detection module uses the system bus for data transmission, so it is easy to eliminate the influence of external changes on the detection results, making the data monitoring of each measured device comparable. Fast alarm: the collection frequency is high with high precision; data can be collected according to user settings, with a minimum period of less than 1 second. Prediction of equipment operation status: complete historical trend calculation and analysis of the temperature values of the tested equipment, combined with working condition information to evaluate the aging state of the switch. Ensure the safety of the power system, provide a basis for equipment condition maintenance, and provide reliable technical data for equipment repair evaluation and predictive maintenance.
