The electrical sector is different from other industries, and maintenance cannot interrupt production at will, which requires the use of non-contact detection methods, and the need to solve the fault before the accident. The substation system is burdened with the power transmission work, the electrical equipment in the station is tight, the line is complicated, and the nodes and large transformers are countless, which is the top priority of the safety prevention of the power sector. With the development of national economy, the challenge of reliability and safety of power equipment is becoming more and more serious.

At present, the application of infrared thermal imaging diagnostic technology in the power sector has become increasingly mature, and its sensitivity can reach 0.05℃, whether it is the internal fault of the power equipment (such as the internal moisture of the lightning arrester), or the thermal fault of the power connection point, it can be clearly displayed, and has played a huge role. Infrared on-line detection is the best fault detection method recognized in the field of electric power at present, and has become an essential and important part of condition maintenance work. The implementation of infrared on-line detection reduces the fault of power system equipment and the risk of personnel working in dangerous operation areas, reduces the cost of personnel maintenance, and improves the efficiency of power system production and maintenance.

Due to the outstanding application effect of infrared technology in the power industry, power users all over the country have adopted the portable infrared point thermometer, portable infrared thermal imager and other infrared equipment. However, there are some problems in using portable infrared thermal imager to check contact overheating. Such as:

(1) The best detection time of infrared thermal imager is often in the early morning (mainly determined by load and infrared imaging interference and other reasons), and manual detection is difficult;

(2) Many substations are far away, and on-site testing by inspection personnel consumes a lot of manpower and material resources, and the timeliness is poor;

(3) Continuous observation, record analysis and comparison of the development trend of some special faults cannot be achieved;

(4) Some old equipment is prone to failure, sudden and rapid development, if not found and eliminated in time, it may cause accidents;

(5) Most voltage heating faults have sudden temperature rise and small temperature difference, which is difficult to identify handheld infrared.

In view of the limitations of portable equipment, in order to maximize the effectiveness of infrared on-line detection, on-line infrared thermal imaging monitoring system came into being. The on-line infrared thermal imaging monitoring system can overcome some shortcomings in the use of portable infrared thermal imager, achieve real-time monitoring of power equipment, ensure the monitoring range or the specified target equipment infrared thermal image monitoring, temperature field data collection, storage and analysis. Real-time detection of the temperature trend change of the object, better evaluation of the heating state of the equipment, and timely detection of hidden faults.

The practical application point of infrared monitoring in substation

Temperature state information and diagnosis are captured and collected by infrared spectrum of each equipment body and connected node in the substation, including but not limited to: Transformers, reactors, current transformers, voltage transformers, high voltage bushings, circuit breakers, isolating switches, capacitors, arresters, power cables, grounding devices, series compensation devices, substation equipment external insulation and insulators, electrical connectors and so on.

The main function of substation on-line infrared monitoring system

The main monitoring functions of infrared temperature measurement system for substation equipment are as follows:

(1) Infrared temperature measurement of the body and joints of all equipment

(2) The appearance inspection of the equipment

(3) The position of the tool brake in the substation

Through the network online control linkage between the background monitoring center and each front-end on-site inspection unit, a complete set of intelligent temperature measurement system for substation equipment is constructed, which effectively improves the work efficiency and detection quality of equipment temperature measurement, reduces the labor intensity and work risk of manual temperature measurement, and improves the operation safety, automation and intelligence level of substation. It provides an efficient and innovative technical means for substation equipment temperature measurement to ensure the safe operation of power grid.