Why do high-voltage power equipment need temperature measurement
Today, with the continuous development of informatization, electric energy has been widely used in various fields. Various power infrastructure that provides electricity energy is widely distributed throughout the country, undertaking the electricity supply in various regions and fields. Among them, the power station, as the main infrastructure, its supply of electricity and reliability are related to the basic guarantee of production and life in various regions and fields. There are various high-voltage equipment installed in the power station, such as wiring strips, switches, etc. These high-voltage equipment are prone to heating problems due to aging, loosening, and other issues. When the heating temperature is high, not only does it need to be shut down for maintenance, but it may also cause serious accidents. In recent years, multiple power outage and fire accidents have occurred in the fields of power transmission, metallurgy and mining, factories and enterprises, urban power supply, etc., caused by overheating of high-voltage electrical contacts such as high-voltage switch contacts, transformer leads, high-voltage busbars, and high-voltage cable connectors, resulting in huge economic losses. Effective monitoring and alarm of overheating of high-voltage electrical contacts is an urgent requirement for safety production. The reliability of high-voltage switchgear under high voltage and high current conditions is closely related to the temperature rise of the isolation switch contacts. During the operation of the power grid, mechanical vibration, contact erosion, and other reasons can worsen contact conditions, increase contact resistance, cause an increase in contact point temperature, exacerbate contact surface oxidation, and lead to local welding or arc discharge at loose contact points, ultimately causing damage to electrical equipment, power outages, or major accidents such as fires. This type of contact overheating fault accident is not only due to the quality problem of the high-voltage cabinet switch itself, but more importantly, due to the lack of effective monitoring methods for the temperature rise of the isolation switch contacts at present.
In the field of sealed high and low voltage distribution cabinet equipment, due to the requirements of the working environment of the sealed distribution cabinet, the working environment of the distribution cabinet is sealed. With the aging of various electronic components and cables, the contact points between important electrical equipment and cables will heat up due to excessive contact resistance caused by dust, looseness, and oxidation. Abnormal heating parts will cause various safety hazards. However, due to the sealing requirements of the sealed distribution cabinet, it is difficult for inspectors to observe the internal working situation through conventional inspection methods. Moreover, due to the fact that conventional internal temperature measurement equipment is non-contact temperature measuring instruments and is easily affected by various electromagnetic or environmental factors such as high and low temperatures inside the distribution cabinet, inaccurate temperature measurement and unstable operation may occur. Disadvantages of. Therefore, accurate online real-time temperature measurement of sealed distribution cabinets has become an urgent problem that needs to be solved in the industry.
Traditional temperature measurement methods for high-voltage equipment
With the continuous increase of electricity load, high-voltage isolation switches often experience abnormal temperature rise in switch contacts, bus connections, and other parts due to aging, poor contact, or excessive contact resistance during long-term operation. If not detected and maintained in a timely manner, it will cause serious equipment accidents. Therefore, solving the problem of switch overheating is the key to preventing such accidents, and achieving real-time temperature monitoring is an important means to ensure the safe operation of high-voltage equipment. However, due to the limitations of high-voltage operation, the heating part of the contact point of the high-voltage isolation switch is difficult to achieve ordinary online temperature measurement for monitoring. The existing temperature measurement technology can only detect which one or some of the high-voltage distribution equipment is in an overheated state, and cannot test which part of the overheated high-voltage distribution equipment is causing the overheat situation. It cannot determine the location of the faulty components, which creates difficulties for equipment maintenance. Installing sensors for temperature monitoring in high-voltage equipment and using infrared thermometers for temperature measurement during inspections are traditional methods of temperature monitoring, which have the problem of low accuracy in temperature measurement results. At present, infrared temperature measurement technology is generally used for monitoring in the market. Infrared temperature measurement is easily affected by environmental factors, and there are still significant limitations and difficulties in the application of temperature measurement in dangerous places. The market urgently needs a temperature measurement device that can implement monitoring in dangerous places, with low cost and high reliability.
Fluorescent fiber optic temperature measurement device applied in the field of electric power:
Temperature measurement of switchgear
Due to the rapid increase in the number of high-voltage switchgear applications in the distribution network, data shows that by the end of the 1990s, there were more than 270000 distribution switches operating in the national power system, which doubled compared to the previous year. However, the high-voltage switchgear in the 10kV distribution network is affected by various factors such as daily operation, external damage, and overloaded lines, resulting in a huge proportion of overheating faults. Especially during peak summer and high load periods of the power grid every year, the overall damage caused by overheating of the contacts inside the switchgear often occurs.
Circuit breaker temperature measurement
The temperature change of the switchgear contacts is the key point for online temperature rise monitoring of the switchgear. At present, low-voltage feed switches or other combination switches use circuit breakers or contactors that are modular in design. Dynamic and static contacts are inevitably used in modular design. However, the use of dynamic and static contacts will inevitably increase a fault point because they need to be frequently plugged in and out, and the current here is generally too high. In case of poor contact, it is easy to have high temperature, which can easily burn out the dynamic and static contacts.
Fiber optic temperature measurement in substations
In production, accidents caused by overheating of electrical equipment connection points account for a large proportion of overall electrical accidents. If not detected in a timely manner, such hidden dangers will pose a great threat to safe power supply. In order to timely detect hidden dangers and avoid accidents, it is necessary to implement online real-time temperature monitoring and intelligent alarm for each connection point of electrical equipment.
Temperature measurement of electrical cabinet
The biggest cause of fire caused by high-voltage electrical cabinets is that individual contacts or circuits in the high-voltage electrical cabinet cannot dissipate a large amount of heat due to long-term aging or poor contact, resulting in local high temperatures, even exceeding the ignition point temperature, and thus causing a fire. In addition to timely strengthening inspections, it is necessary to promptly eliminate hidden dangers in response to these abnormal points and nip accidents in the bud.
Characteristics of fluorescence fiber optic thermometer
FJINNO’s fluorescence fiber optic thermometer has the characteristics of accurate temperature measurement, high resolution, and resistance to electromagnetic interference. The fluorescence fiber optic thermometer can be reliably applied in environments with strong electromagnetic interference, especially in harsh temperature measurement environments. And combined with advanced fiber optic temperature measurement technology, the communication control between the upper computer and the data acquisition system microcontroller, the interface is beautiful, the operation is simple, and it can monitor and save data in real-time online, improving the automation and intelligence of the system.