What is a switchgear temperature monitoring system

Senzor temperature od optičkih vlakana, Inteligentni sustav nadzora, Distribuirani proizvođač optičkih vlakana u Kini

Online temperature detection of high-voltage switchgear power supply system

High voltage switchgear has a metal enclosed structure that can complete the switching control of AC circuits. It is widely used in high-voltage power supply systems and plays an irreplaceable role in monitoring and measuring, line disconnection, and fault protection of high-voltage power supply systems. Indoor metal armored mobile switchgear (KYN) is widely used in power supply systems due to its advantages of easy maintenance, simple structure, good operability, and high safety. Međutim, the metal fully enclosed structure of the switchgear results in poor heat dissipation, and high voltage and high current generate a lot of heat. Under these conditions, infrared temperature measurement technology cannot effectively monitor internal equipment. Stoga, the high-voltage AC power supply switchgear system often experiences cable pressure contacts, switch contacts overheating and burning, and even fire and power outages, which poses a great threat to the reliable operation of the high-voltage power supply system and causes huge economic losses. Stoga, effective online temperature fault detection and control of KYN internal components are very important. It is necessary to timely and effectively detect the temperature of the components inside the enclosed cabinet, control and handle the heating hazards in a timely manner, make correct predictions and timely diagnosis and treatment of heating faults, and ensure the stable operation of the high-voltage power supply system.

Online Temperature Monitoring Technology for High Voltage Switchgear

In order to improve the reliability of switchgear, its internal structure and functions are becoming increasingly complex, so power outage maintenance of switchgear is becoming more and more complicated and difficult. Stoga, it is necessary to conduct testing to ensure reliable operation. Domestic and foreign technological forces have conducted a large number of scientific experiments and practical applications on site, and found that fluorescence fiber temperature measurement i wireless active temperature measurement technology are very effective in temperature detection in closed systems.

Fiber Bragg Grating Temperature Measurement System

The closed temperature detection technology of fiber Bragg grating was successfully developed in Ottawa in 1978, and then the technology began to develop rapidly. Breakthroughs and practical applications were made in many related fields because fiber Bragg grating has strong photosensitivity. When the physical characteristics of fiber Bragg grating, such as temperature and stress, change to a certain extent, it will cause the effective refractive index of the fiber Bragg grating core to change accordingly, and the wavelength of the grating will also change accordingly. By obtaining the wavelength change signal and converting the wavelength change pattern into corresponding level signals, temperature measurement of components sealed inside the switchgear can be achieved. Place the fiber Bragg grating sensor at the bottom of the switchgear for temperature detection. When the sensing system is working, the regulator can emit narrowband laser, which is then dispersed by multiple optical switches to reach each sensor. If the wavelength obtained is equal to the wavelength of the grating core, it is in the emission state, and the laser returns to the regulator through the multiple optical switches of the coupler. The regulator will obtain the temperature parameters of each component in the switchgear and send the information data to the upper computer through the A/D digital to analog conversion module. The software system in the upper computer has displayed the temperature signal through the display system, which can intuitively obtain the temperature parameters of the switchgear. The upper computer can also complete functions such as temperature data storage, query, warning, and analysis. The advantages of fiber Bragg grating temperature sensing are high sensitivity, small size, and strong anti-interference ability. Međutim, the generation of its signal requires high-resolution spectra, which results in high cost and complex structure. During its construction, all lines need to be disconnected, and the fiber itself will affect the insulation performance of the system.

Wireless active temperature measurement system

The working principle of wireless active temperature measurement technology is basically the same as that of general temperature measurement technology, which uses traditional temperature sensors to obtain temperature signals, and then uses wireless data transmission to transmit the signals to the upper computer. In this design, the temperature sensor adopts a relatively traditional semiconductor or thermocouple type sensor, which requires a battery or induction coil for power supply. The battery power supply method is relatively easy to implement, but replacing the battery is a very troublesome task. The induction coil power supply requires inducing voltage from the primary measurement circuit of the device to supply the sensor. Međutim, changes in the primary side current will have a significant impact on the temperature measurement accuracy, resulting in increased noise. In short, the wireless active sensing method has a simple structure, mature technology, easy use, and does not require wiring, which causes trouble. Međutim, the power supply of the sensor has become the main challenge of this system.

Wireless Passive Temperature Measurement System for Switchgear

Wireless passive temperature sensing technology. Compared with fiber Bragg grating and wireless active temperature measurement technology, it has obvious advantages in reliability, feasibility, economy, and safety. Wireless and passive are the main technological sources for its advantages, and its main working principle is the use of surface acoustic wave (SAW) Tehnologija. In 1885, the famous British physicist Raleigh accidentally discovered the existence of surface acoustic waves while studying seismic waves, which were later widely used in high-end technological fields such as military, radar, and communication. In recent years, SAW sensing technology has made new breakthroughs in reliability and accuracy, and has gradually been introduced into the temperature monitoring system of power system switchgear.

Composition of SAW sensing system

The system uses a hierarchical structure. It is divided into four layers from bottom to top, namely remote terminal layer, monitoring application layer, data transmission layer, and field device layer. It is composed of multiple wireless passive sensor networks, and the signals generated by multiple sensors are collected by a data collector and then sent to the data transmission layer through serial port or wireless data transmission mode. The data transmission layer corresponds to the interval layer in the intelligent substation, which summarizes and processes the data uploaded by multiple collectors to achieve remote intelligent control of sensors and input/output of their signals. The monitoring application layer corresponds to the station control layer, mainly used for centralized collection, warning, monitoring, storage, analysis, and expert diagnosis of wireless temperature testing signals. The remote terminal layer is used for overall system management and can use remote devices such as laptops, servers, mobile phones, tablets, itd., to achieve alerts and monitoring of system status through remote management.

Characteristics of Wireless Passive Temperature Detection System

Solved various drawbacks of fiber Bragg grating and wireless active temperature measurement technology, such as line insulation, sensor power supply, complex wiring, and high costs. The communication mode of bus is used, which facilitates the updating and expansion of the system. The system runs stably and reliably, and can complete long-term online temperature detection and remote alarm monitoring of the internal components of the enclosed switchgear. It can predict the heating hazards generated inside the enclosed high-voltage switchgear in advance and provide a strong foundation for its efficient and continuous operation. U isto vrijeme, the SAW sensing and monitoring system can also be used in technical fields such as cable or contact aging, cable fire prevention, lightning arrester fuse monitoring, transformer overload monitoring, and complex structure cable monitoring in high-voltage power supply systems, with great development prospects. Due to SAW being a new technology with insufficient maturity, there is still a lot of room for development in terms of stability. Currently, researchers are further improving its anti-interference and long-distance transmission capabilities to better apply and develop SAW technology. In conclusion, this article focuses on the problem of high temperature faults in high-voltage switchgear of power supply systems. Based on the shortcomings of sealing temperature detection technology, a temperature detection sensing technology that can meet the internal components of high-voltage switchgear in a sealed state, namely SAW wireless passive temperature sensing technology, is elaborated. This technology has the advantages of high accuracy, sensitive control, simple structure, and good reliability. With the continuous development of live detection technology in high-voltage power supply systems, traditional power outage pre test maintenance technology will be eliminated and replaced by non power outage maintenance technology. The application of SAW wireless passive temperature sensing technology in high-voltage power supply systems is of great significance in state assessment, fault monitoring, and improving maintenance efficiency. To provide reliable guarantees for the efficient operation of the power supply system, the next step for this technology is to further improve and enhance its signal anti-interference ability and transmission distance, with broad prospects.

Karakteristike Fluorescent Fiber Optic Temperature Measurement

1. Immunity to electromagnetic interference (fiber optic cable material is silicon dioxide, front-end temperature sensing material is inorganic material).

When the fiber optic cable is 40cm above ground, it can withstand a voltage of 100KV (this test is not a limit test).

3. The fiber optic probe is compact, and the fiber diameter of the product can reach ф 600um.

4. Fast response speed.

5. Flame proof and explosion-proof, the melting point of optical fiber is 1670 °C.

Application field of fluorescent fiber optic temperature measurement

1. Environment with strong magnetic field and electric field interference.

2. Flammable and explosive environments.

3. Medical, petrochemical and other environments.

4. High and low voltage sides of transformer windings.

5. Rail transit locomotive environment.