Application of the hottest infrared thermal imager

  • Detail

Application of infrared thermal imager in fault detection of power equipment

there are many kinds of faults of power equipment, but most of them are accompanied by heating. From the perspective of infrared diagnosis, it is usually divided into external faults and internal faults. As we all know, in the operation of power system, the current carrying conductor will produce resistance loss due to current effect, and there are a large number of connectors, connectors or contacts on the whole circuit of electric energy transmission. Ideally, the contact resistance of various connectors, joints or contacts in the transmission circuit is lower than that of the connected conductor, then the loss and heat of the connection part will not be higher than that of the adjacent current carrying conductor. However, once the contact resistance increases due to poor connection of some connectors, joints or contacts, there will be more resistance loss and higher temperature rise at this part, resulting in local overheating. This is usually an external fault

the characteristics of external faults are: local temperature rises, which is easy to be found by infrared thermal imager. Controlling raw materials is the key to completely solve the color difference. If it cannot be handled in time, the situation will deteriorate quickly, which is easy to cause accidents and losses. External faults account for a large proportion of faults

the so-called internal faults of high-voltage electrical equipment mainly refer to various faults caused by electrical circuit faults enclosed in solid insulation and equipment shell and insulation medium deterioration. Because this kind of fault occurs in the interior of electrical equipment, the temperature rise of the reflected equipment surface is very small, usually only a few K. Detecting this kind of fault requires high sensitivity of detection equipment

the characteristics of internal faults are: small proportion of faults, small temperature rise, great harm, and high requirements for infrared detection equipment

according to the long-term measured data provided by relevant units and the comprehensive statistics of a large number of cases, the external thermal defects of power equipment generally account for 90% - 93% of the total index of equipment defects, and the internal thermal defects only account for about 7% - 10%

in the power industry, thermal imagers have been used in the safety maintenance of equipment for a long time, through which the thermal defects of electrical equipment and lines are detected, such as transformers, bushings, circuit breakers, knife switches, mutual inductors, power capacitors, lightning arresters, power cables, buses, conductors, combination appliances, insulator strings, low-voltage appliances, and the secondary circuits of equipment with current, voltage heating effects or other heating effects, This can play a key and effective role in the timely discovery, treatment and prevention of major accidents

the so-called thermal defect of electrical equipment usually refers to the heating phenomenon caused by the internal or external factors of the system, which is detected by certain means

according to the different causes of defects, we usually summarize them into three kinds: one is the heating caused by the reduction of conductive cross-sectional area of components exposed to air for a long time due to the influence of temperature and humidity, or the poor contact caused by surface scaling, or the damage of components caused by external force. If the joint is poorly connected, the bolts and washers are not compressed; Corrosion and oxidation during long-term operation; Corrosion caused by active gas and dust in the atmosphere; Poor component materials and poor processing and installation technology cause conductor damage; The actual cross-section of the conductor is reduced due to mechanical vibration and other reasons; The load current is unstable or exceeds the standard, etc

the other is due to the internal failure of the appliance itself, such as the excessive resistance caused by the poor contact of the internal connecting parts; Aging, cracking and falling off of insulating materials; Internal components are damp, and the loss of components increases; Andy postlethwaite, senior vice president of BASF High Performance Materials Asia Pacific, said: "When it comes to the degree of freedom of design, the pipeline is blocked, etc.

for those equipment and components that can be directly observed, the infrared thermal imager can find the hidden heat hazards of all connection points. For those parts that cannot be directly seen due to shielding, it can be analyzed according to the heat transfer to the external components, so as to draw a conclusion. Because the actual situation on the site is ever-changing, even if you get it through the thermal imager If you want to make an accurate judgment on a hot picture, you may be affected by many factors. Such as current temperature, air volume, load, etc. We can make relevant analysis and make corresponding judgments according to different characteristics, such as:

in order to ensure the safe and efficient operation of power production, higher requirements are put forward for the condition based maintenance of power equipment. Since condition based maintenance mainly depends on the condition detection and monitoring means of equipment in operation, the operation condition detection and monitoring of power equipment always plays an important role in power safety production. As a new technology, infrared imaging technology has incomparable advantages in the operation state detection of power equipment. Infrared imaging is based on the thermal state distribution of the equipment to diagnose whether the equipment is in good condition or not. It has the advantages of non-stop, non-contact, long-distance, fast and intuitive imaging of the thermal state of the equipment. Because the thermal image of the equipment is the real description of the thermal state and temperature distribution of the equipment under the operating state, and whether the thermal distribution of the power equipment under the operating state is normal or not is an important feature to judge whether the equipment is in good condition. By using infrared imaging technology, the status and hidden defects of the equipment can be diagnosed through the analysis of the thermal image of the equipment

the following power equipment status detection can be carried out by using infrared imaging technology. Due to the small risk and fault diagnosis of establishing a recycled plastic particle factory

● operation state detection and internal and external center fault diagnosis of high-voltage electrical equipment:

● oxidation corrosion and poor connection defects of all kinds of conductive joints, clamps and wiring pile heads

● poor contact defects of central contact in various high-voltage switches

● poor combination between the knife edge of the isolation knife brake and the contact piece, as well as the rotating cap and the ball head

● various CT primary inner and outer center connection defects, body and oil insulation defects, as well as inner center iron core and coil abnormal defects, overheating depression

● all kinds of Pt insulation defects, lack of oil and abnormal overheating defects of inner center iron core and coil

● overheating of various capacitors, poor oil insulation of coupling capacitors and oil shortage (low oil level) defects

● damp defects in the inner center of various arresters, aging of inner central components or abnormal nonlinear characteristics

● all kinds of insulator surface pollution defects, zero value insulator detection, degraded insulator detection

● generator operation state detection, brush and collector ring contact state detection, inner center overheating detection

● the power transformer box is abnormally overheated, the eddy current is overheated, the upper and lower ends of the high and low voltage bushings are poorly connected, and the oil filled bushing is lack of oil (low oil level)

● all kinds of motor bearing shells have poor contact and the inner and outer centers of the body are abnormally overheated. (end)

Copyright © 2011 JIN SHI