In the power system,SF6Gas is widely used due to its excellent insulation and arc extinguishing propertiesGISCombination electrical appliances, switchgear and other high-voltage equipment. However,SF6Gas leakage not only reduces the insulation performance of equipment, but its decomposition products may also pose a health hazard to personnel.SF6The leakage online monitoring and alarm system has become a key technical equipment to ensure the safe operation of the power grid by sensing changes in gas concentration in real time.

1、 Multi parameter fusion monitoring, constructing a safety protection network

The system adopts a distributed sensor network, which can monitor simultaneouslySF6Gas concentration（0-3000ppm）Oxygen content（1-99%）Environmental temperature（-10~+60℃）And humidity（10-99%RH）The four core parameters. whenSF6Concentration exceeds1000ppm(Adjustable) or oxygen concentration below18%When adjustable, the system immediately triggers a three-level response mechanism: first, a red warning is displayed on the local display unit, and at the same time, throughRS485Bus sends to the central control roomMODBUS-RTUProtocol alarm signal and activate on-site sound and light alarm. some500kVThe application data of the substation shows that the system canSF6The discovery time of leaks has shifted from traditional manual inspections2Shorten hours to30Within seconds.

2、 Intelligent linkage control to achieve active safety protection

The system is equipped with an intelligent ventilation control module, which has three working modes: when detectedSF6When the concentration exceeds the standard or oxygen is insufficient, the fan will automatically start for forced exhaust, and continue ventilation after the gas concentration returns to normal15minute; Support timed ventilation function, which can set automatic ventilation during specific time periods every day; Provide a manual forced ventilation button for temporary operation by maintenance personnel. In the practice of a substation in a humid southern region, this function ensures that the humidity in the switch room remains stable for a long time50%RHThe following effectively reduces the risk of equipment condensation.

3、 Humanized interactive design to improve operational efficiency

System configuration10.2Inch color touch screen, supporting real-time parameter display and historical data query (storage)360Functions such as continuous data tracking and alarm record tracing. Specially designed human infrared sensing module, which can be used by staff entering the power distribution room10Automatically play environmental safety voice prompts within a range of meters. In the application of a substation in a cold region of Northeast China, the system ensures stability through heating modules-30℃Work normally in the environment and cooperateIP65The protection level design has achieved year-round fault free operation.

4、 Engineering application value

The system has been implemented nationwide23Provincial power grid companies have promoted and applied, with cumulative installations exceeding8000Set. Practical applications have shown that itSF6Concentration detection accuracy<3%FSRepetitive error<5%FSSatisfyDL/T 595-2016According to the Gas Supervision Regulations for Sulfur Hexafluoride Electrical Equipment. Through real-time monitoring and intelligent linkage, a provincial power grid company's statistics show that the equipment failure rate has decreased42%Annual decreaseSF6The gas supply exceeds the limit1.2Ton, equivalent to reducing carbon dioxide emissions equivalent3.6Ten thousand tons.

With the deepening of smart grid construction,SF6The leakage online monitoring and alarm system is being upgraded towards wireless sensing, edge computing, etc'transparency'The state perception system for substation equipment provides important technical support.