In the power system,SF6As a key insulation medium for high-voltage switchgear, gas leakage monitoring is directly related to equipment operation safety and personnel health.SF6The online leakage monitoring and alarm system has become an important infrastructure for the construction of intelligent substations by sensing changes in gas concentration in real time. This article systematically elaborates on the practical points of the system from the perspectives of engineering application and operation and maintenance management.

1、 Typical application scenario analysis

1. GISEquipment room environmental monitoring

In220kVIn substations with voltage levels and above, the system uses a distributed sensor network toGISConduct comprehensive monitoring in the equipment room. The application data of a certain ultra-high voltage direct current project shows that it adopts16Channel monitoring system (coverage)800After the ㎡ equipment area,SF6Leak localization accuracy reaches±2mImproved compared to traditional point based monitoring80%Accuracy.

2. Application of Prefabricated Cabin Substation

For modular prefabricated cabins, the system adopts a compact design that integrates gas detection, temperature and humidity control, and ventilation linkage functions. In a smart substation project in Xiong'an New Area, the cabinSF6When the concentration exceeds the standard, the system15Complete the alarm within seconds and activate the exhaust system to maintain the oxygen concentration in the cabin at all times19.5%-23%Safety range.

3. Special environmental adaptability renovation

In high-altitude areas of the Qinghai Tibet Plateau, the system corrects detection data through pressure compensation algorithms to ensure accuracy4500mAltitude-35℃ofringUnder the circumstances,SF6Concentration measurement error<5%In humid coastal environmentsIP68Protection level sensor, combined with electric heating and dehumidification device, effectively solves the problem of sensor failure caused by condensation.

2、 Core points of system maintenance

1. Regular calibration management

It is recommended to6Perform professional calibration once a month using standardsSF6Three point calibration of gas generator（500ppm/1000ppm/2000ppm）. According to statistics from a provincial power grid company, standardized calibration can reduce the false alarm rate of the system2.3%drop to0.5%following.

2. Sensor cleaning and maintenance

Use a dust-free cloth dipped in isopropanol to clean the surface of the sensor every quarter, paying special attention to avoiding liquid infiltration into the protective cover. In heavily polluted areas, it is recommended to install dust filters and clean them monthly to extend the service life of sensors30%The above.

3. Communication network guarantee

adoptRS485When designing the bus structure, it is necessary to ensure that the terminal resistors match（120Ω）The cable length shall not exceed1200m. Some500kVIn the substation renovation, the communication interruption caused by signal attenuation was successfully solved by changing the bus topology to a star topology.

3、 Innovative Practice of Intelligent Operation and Maintenance

1. Big data analysis applications

Establish equipment health records and discover through historical data mining that a certain220kVsubstationSF6In a leak event, the system was not affected before the leak occurred72The concentration has shown a slow upward trend in the hour, providing a key basis for preventive maintenance.

2. Mobile Operations Platform

Develop an operation and maintenance system based on WeChat mini programs to achieve real-time data viewing, alarm push, work order generation, and other functions. In a smart grid project in the Guangdong Hong Kong Macao Greater Bay Area, the response time for operation and maintenance is from2Shorten hours to20minute

With the development of digital twin technology, the new generationSF6Monitoring system is being integratedARFunctions such as inspection and predictive maintenance are used to promote the operation and maintenance of substations'unattended+precise intervention'Mode transformation. Through continuous technological innovation and standardized management,SF6The leakage online monitoring and alarm system will continue to provide protection for the safe operation of the power grid.