How to apply the multi-channel high-precision fiber optic grating temperature online monitoring system for substations in practice

Ljósleiðari hitaskynjari, Snjallt eftirlitskerfi, Dreift ljósleiðaraframleiðandi í Kína

The characteristics of multi-channel substation fiber optic temperature online monitoring
Starting from high sensitivity signal sensing and other aspects, the system develops high-precision online temperature signal recognition technology and applies multi-channel optical wave measurement and transmission technology to overcome signal offset caused by long working time of optical devices. Through the joint work of high sensitivity fiber optic grating sensors, high-speed and high-precision acquisition cards, professional analysis and diagnosis software, and remote communication modules, temperature change signals in equipment such as switchgear and transformers in substations can be monitored online, and temperature change levels can be calibrated with different colors to provide real-time warning of equipment health status and maintenance guidance suggestions for operation and maintenance personnel. The remote data communication module of the system can upload real-time monitoring data and warning results to the control room through TCP/IP or GPRS, enabling management personnel to timely grasp the temperature changes of the substation switchgear and transformers, ensuring the long-term stable and reliable operation of the substation equipment.

What are the difficulties of the temperature monitoring system in substations
From the current research and application of online temperature monitoring in substations, the difficulty lies in the anti electromagnetic interference and measurement accuracy of temperature signal extraction. Due to the fact that most substation equipment is located in a strong electromagnetic field and high voltage environment, it is severely affected by interference signals from the air and cable connection equipment. The measurement of parameters such as the contact temperature of high-voltage switchgear and the top oil temperature of transformers requires sensors to have good insulation and strong resistance to electromagnetic interference, and their size is small. Almennt, electronic sensors measure and transmit signals in the form of current, voltage, or resistance. The signal is easily affected by strong electromagnetic fields and high voltage, and their measurement accuracy is often low or even impossible to achieve. In the early stage, some substations installed and applied temperature online monitoring systems, but due to poor performance in temperature signal extraction and measurement accuracy, false alarms and missed alarms are prone to occur.

Solution for multi-channel substation temperature online monitoring system
Fiber Bragg Grating Sensing Demodulation Technology
The system adopts advanced semiconductor lasers, high sensitivity photodetectors, and automatically adjusts the gain. It has the characteristics of being uncharged, inherently safe, not affected by electromagnetic interference, moisture-proof, o.s.frv., overcoming the signal offset caused by long working time of optical devices.

Online temperature signal recognition technology
By applying signal recognition techniques such as knowledge base decision analysis, the monitoring system can achieve long-term stability and reliability. It can overcome signal offset caused by long working hours of optical devices, greatly improve demodulation accuracy and accuracy. The temperature measurement accuracy reaches ± 1 ℃ in the full range, 0.5 ℃ in the local area, and repeatability can reach 1 pm.

Automatic analysis and judgment technology
The system software displays monitoring variables in real-time, quickly queries the curve of variables at each point over time, and can achieve dynamic monitoring of temperature trends. The hardware connection is simple, the software interface is friendly, and all analysis and diagnosis are automatically completed in the background. Users can proficiently operate it after simple training. On the basis of extracting and identifying temperature signals from switchgear and transformers, a substation fault warning technology based on temperature monitoring is developed to provide early warning for faults of different levels and provide maintenance guidance and suggestions for operation and maintenance personnel.

Information integration management technology
Detailed management of temperature information, transformer temperature information, and maintenance records of high-voltage switchgear can be carried out through industrial computers and system integration software. Historical information and replacement maintenance records can be viewed at any time. Integrate the dynamic parameters of various monitoring devices, establish a comprehensive database of substation equipment status, automatically generate equipment status parameter reports and trend curves, combine trend analysis and relative comparison of equipment historical parameters, integrate computer processing functions, and achieve remote and on-site status monitoring, diagnosis, and evaluation of equipment.

Modular structural design
The system adopts a modular structure design, which has advantages such as small size, simple structure, convenient portability, and powerful functions. The signal acquisition unit is installed and digitized on site according to the distribution of on-site equipment in the substation, and communicates with the station center management unit through on-site industrial bus, fiber optic channel or wireless module. The interface configuration is an open communication structure, with multiple interfaces such as network and serial ports for data input and output. The system is easy to expand and has strong compatibility. It can support real-time automatic control, intelligent adjustment, online analysis and decision-making, and collaborative interaction as needed.

Trefjar Bragg rist (FBG) is a new type of all fiber passive device. Changes in temperature, stress, and other factors can cause changes in the center wavelength of the reflected light. As FBG encodes the detected information with wavelength, which is an absolute parameter, it is not affected by system losses caused by light source power fluctuations and fiber bending. Þess vegna, FBG sensors have excellent reliability and stability. There is inherent compatibility between fiber Bragg gratings and optical fibers, making it easy to achieve wavelength division multiplexing and quasi distributed sensing. Fiber optic grating sensors have the characteristics of small size, létt þyngd, low transmission loss, no electromagnetic interference, háspennuþol, o.s.frv., which can accelerate the realization of the requirements for substation informatization, automation, interactivity, and other aspects in the construction of smart grids.

The development and application of multi-channel high-precision online temperature monitoring and early warning for substations can timely obtain the characteristic parameters of equipment such as switchgear and transformers, overcome the limitations of traditional manual periodic inspections, and combine fault diagnosis system software to analyze and process equipment. This will improve existing technological shortcomings and establish a complete online monitoring system, which is of great significance for improving the safety, áreiðanleiki, and economy of substation operation, and extending equipment life. Á sama tíma, it will also promote the application and promotion of fiber optic grating sensors in online monitoring of substation equipment, providing support and guarantee for the construction of smart grid substations with digital information, networked communication platforms, and standardized information sharing.