The automation control of power equipment and unattended on-site have become an inevitable trend. At present, the intelligent grid reconstruction project is fully developed, In order to understand and master the situation of each key equipment in real time and directly, and respond promptly to sudden situations. It requires the establishment of a monitoring and control center, which can monitor the relevant data, environmental parameters and images of key equipment such as transmission and distribution power plants, substations, transmission and distribution lines, etc.
The electric power system "Electrical equipment charged infrared diagnostic application specification" pointed out that in the construction of unattended substation, "five remotes" technology should be highlighted: Remote testing, remote signaling, remote control, remote adjustment, and remote viewing, The realization of the remote viewing function is basically based on environmental monitoring, security and theft, and can directly reflect the temperature distribution of the equipment in the operating condition of the power grid.
After decades of experience feedback, Wuhan Dikai Optoelectronics has developed a dedicated electrical equipment online monitoring camera according to the requirements of the specification and the requirements of the power system site.
The characteristics of infrared cameras
1. It can transmit infrared sensing images of detected objects in real time and remotely, with first-line features.
2. It can control the cluster detection group on a large scale.
3. It can realize the temperature rise or hot spot positioning, temperature measurement, analysis and alarm for the monitoring target.
4. It can capture, record and play back the monitoring area.
5. It can arbitrarily set presets for multiple targets of the monitoring range class, realize fixed point, timing, auto matic monitoring of inspection
6. It can set an over-temperature scheduled alarm for the monitoring target, and can alarm in time when it encounters over-temperature and generate a daily report
7. It can automatically generate daily inspection logs, including the maximum temperature and picture of each preset.
8. It can monitor the computer and perform real-time temperature analysis of points, lines and regions on the monitoring screen.
9. It has rich expansion interfaces, can be used for interface development, and is easy to connect with other devices to form a large integrated network.
Electric power equipment is generally related to temperature, such as transformers, switches, knife gates, and auxiliary equipment. In the event of an accident, these equipments are not only economically expensive, but also harmful to humans. Therefore, the use of infrared imaging to detect grid equipment is a inevitable road in historical development. If we can make timely prevention before the problem occurs, it will minimize the loss, which is also the inevitable trend of modern power grid.
Finding problems in time and ensuring the normal operation of the grid plays a decisive role in extending the life of the equipment.
Field application point of infrared camera
Electrical installations: It can find poor joints or looseness, unbalanced load, overload, overheating and other hidden dangers. These phenomena may cause arc short circuit to burn and catch fire.
Transformer: It can find hidden dangers: loose joints, overheating of the casing, poor contact of the tap changer, overload, unbalanced three-phase load, poor blockage of the cooling pipe, The winding of the air-cooled device can be directly measured with an infrared pyrometer to check the excessive temperature. Any excessive temperature indicates damage to the winding of the air-cooled device, which may cause the arc short-circuit to burn and ignite.
Generator: It can detect excessive bearing temperature, unbalanced load, winding short circuit or open circuit, carbon brush, slip ring and collector ring heating, which can cause damage to the core or winding coil caused by the problematic bearing.
Connector: The electrical connection part will gradually loosen the connector, which will generate heat by repeated heating or expansion, resulting in carbon accumulation, corrosion,
Ballast: If the ballast is overheated, it will cause overheating and smoke.
Comparison of historical data using infrared cameras
In terms of electric power transformation, the application of infrared detection is the most extensive. Many countries have formed a routine inspection system, and set up a special monitoring vehicle for thermal imager to conduct substation inspection. If the detected overheating occurs, it is necessary to notify the maintenance department. If required, you can measure other parameters such as resistance after the inspection for comparison. It is necessary to strengthen the monitoring of the equipment showing the special thermal image. For the detection cycle, some regulations are checked once every two years for major substations, and some are tested all the substations every year, and some use infrared continuous monitoring for the main targets. Due to the obvious effect of thermal image detection, the number of over-temperature components has decreased year by year, and some have fallen from in 1975 to 0.5% in 1978. Some failure rates have dropped from 2.35% in 1971 to 0.24% in 1977. The role of infrared detection power equipment was first confirmed in 1968 by some countries, and Some countries have determined that electric thermal imaging is a standard method. China's electric power test research units and production and operation departments have also carried out a large number of infrared detection, and diagnosed many faults, which makes the social and economic benefits obvious. At the same time, they are exploring a set of infrared diagnostic techniques that are effective for power production. Guidelines for power infrared diagnostic techniques have been developed.
In terms of power transmission, due to the development of power production,
More and more long lines will cross the mountains and rivers which the terrain is complex, and the usual ground inspection lines can not meet the requirements. Some countries where conditions permit have used helicopters to mount thermal imaging cameras for line inspection. Some have been listed as regular patrol methods, and some are equipped with dual-engine special planes. The experimental research work of the aircraft with the thermal imager for the inspection line began in the early 1970s. After continuous improvement, the cost of failure was reduced year by year. By 1987, the cost was lower than the initial half.
The results of the joint detection are divided into four cases, including micro temperature, temperature, heat and abnormal heat. The report maintenance engineer will determine the order of maintenance based on weather and load.
China's Hubei, Henan, Northeast, North China, Guangdong and Northwest China's power systems have carried out experimental research on infrared aerial survey lines, and have explored a lot of experience, and have achieved certain results. Ground detection research based on national conditions is also being effectively promoted