Fiber optic temperature sensor, Intelligent monitoring system, Distributed fiber optic manufacturer in China
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Overview of solutions for fluorescent fiber optic temperature controllers for dry-type transformers
The measurement range specified in the “Electronic Temperature Controller for Transformers” (JB/T7631-2016), which uses Pt100 as the traditional temperature sensor, can only be limited to below 1000V, and this sensor is made of metal material, which poses a safety hazard. Therefore, temperature sensor probes and leads for measuring transformer winding temperature have higher requirements.
The fiber optic temperature controller uses our company’s independently developed fluorescent fiber optic temperature sensor as the temperature sensing element. This temperature sensing element is immune to electromagnetic interference and resistant to high voltage (100KV/fiber to ground lead distance of 0.4m). Fluorescent fiber optic temperature measurement completely solves potential safety hazards from the source of temperature measurement and improves the safety level of transformers.
Target of fluorescent fiber optic temperature measurement system for dry-type transformers
For the operating environment of dry-type transformers, isolation and shielding from external electrical interference signals are achieved from the power supply, signal input end, signal output end, and temperature control box shell.
No metallic substances, intrinsic safety.
In response to vibration, dust, moisture, oil and other on-site working environments, multi-layer protective measures are taken to ensure that the fiber optic temperature controller has good electromagnetic compatibility, ensuring stable and reliable operation.
Design principles of fluorescent fiber optic temperature measurement host for dry-type transformers
Principle of practicality
The system construction adheres to the principle of practicality. On the basis of practicality, progressiveness and foresight are considered, and standard, advanced and mature products and development platforms are selected to build a system that is practical and solves practical problems.
Standardization principle
The system software and hardware platforms and application development tools used in application construction should comply with national standards, standards of the Ministry of Information Industry, relevant technical specifications and requirements of the company.
The principle of uniformity
Following the policy of centralized information management, overall planning, overall design, and step-by-step implementation, the implementation process embodies four unified principles: unified leadership, unified planning, unified standards, and unified organization and implementation.
Reliability principle
The software and hardware resources need to ensure the uninterrupted and reliable operation of the fiber optic temperature measurement system for 7 × 24 hours. Therefore, it is necessary to equip a complete design of reliability measures to ensure the highly reliable operation of the system and fully consider the reliability requirements of key system applications.
Reliable security mechanism
This system adopts a series of secure encryption measures, with a built-in 64 bit encryption algorithm. The system has higher security and can effectively prevent data leakage and theft, ensuring the security, accuracy, and integrity of the system’s data, and preventing illegal operator operations and legitimate operator illegal operations.
The operation interface is simple, friendly, and highly intelligent
The system automatically checks the legality of the input data and provides friendly prompts for operator errors.
Stable operation and reliable data.
The platform is easy to operate, easy to master, and the installation process is simple. Data can be automatically generated into various reports as needed, improving management efficiency.
Principle of Fluorescent Fiber Optic Temperature Measurement
The fiber optic probe consists of three parts: ST connector, fiber optic cable, and end temperature sensing end. The ST connector is the connection part with the photoelectric module; Fiber optic cable is the transmission part, with quartz fiber inside. The quartz fiber has a coating and cladding on the outside, and a Teflon protective sleeve on the outermost part; The end temperature sensing end contains temperature sensitive rare earth materials, which excite fluorescence after being irradiated by fixed wavelength light. After the excitation stops, the relationship between the decay time constant of fluorescence afterglow and temperature is a quasi exponential function. The temperature can be obtained by measuring the time constant of afterglow; The optical fiber is resistant to high temperatures of 200 ℃ and has an outer diameter of 3mm. Long term bending radius of 13.2cm. Short term bending radius 4.4cm
The sensor probe material is rare earth fluorescent material, and its biggest advantage compared to other optical fiber temperature measurement principles is that temperature measurement is independent of light intensity. It has strong compatibility with the inconsistency of fluorescence intensity, optical path attenuation, and circuit drift in hardware. Therefore, it is not affected by electromagnetic interference and can withstand high voltage, making it very suitable for high voltage, strong magnetic field, flammable and explosive temperature measurement occasions.
Introduction to wiring and installation of fiber optic temperature controllers for dry-type transformers
1.1 Structural framework
The system consists of three parts: a fluorescent fiber optic temperature controller, a fluorescent fiber optic probe, and fiber optic communication software.
The data transmission between the backend system and the temperature measurement terminal adopts RS485 communication method.
All data collection, management, and temperature display are completed by communication software, and the system mainly realizes data collection and monitoring of temperature measurement. The fiber optic temperature measurement terminal integrates multi-channel fluorescent optical fibers, providing external RS485 communication, anti-interference, and corrosion-resistant design.
Application functions of fiber optic temperature controller system for dry-type transformers
1.1 Real time monitoring
The data collection density can be set according to customer needs, and the system will collect data regularly based on the set parameters. Then, it will be displayed in table form or curve drawing to achieve real-time monitoring. Real time monitoring of equipment operation status; Real time monitoring and recording of reactor temperature.
1.2 Basic functions
1) Temperature data query
1. You can query temperature data for specified dates, browse, print, and export to Excel.
2) Historical temperature data storage
1. Permanently record temperature data
Introduction to fiber optic temperature controller for dry-type transformers
2.1 Main features
The fiber optic temperature controller is embedded installation. This product has unique technical advantages in temperature measurement in special environments such as high voltage, strong electromagnetic interference, etc. The temperature hotspot and measurement signal receiving part of the fluorescent fiber optic temperature sensor do not use electrical connections, which can work with high precision and stability for a long time, greatly improving its application range. The fiber optic temperature controller has high accuracy and sensitivity, is resistant to high pressure and can be remotely monitored, has a long lifespan, is small in size, makes instrument maintenance simple and convenient, and ensures safe transportation.
2.2 Main functions
Provide three winding temperature measurement; Automatic/manual start stop cooling fan function; Digital compensation function for display values of each channel
The digital tube displays the temperature of the transformer’s hot spot on a circuit;
Provide black box function, which can record temperature data and historical maximum temperature before three power outages;
Provide transformer door cabinet point opening alarm function;
Provide functions such as over temperature alarm, fault alarm, trip, etc
Provide RS485 communication function, communication with time mark can receive timing or MODBUS-RTU protocol (F function)
2.3 Additional features
Provide 4 independent 4-20mA analog current output functions; (E function)
PTC nonlinear resistance sensing temperature measurement protection function; (C function)
Alarm function for winding temperature rise rate and iron core temperature rise rate;
The communication protocol can adopt methods such as Profibus, IEC60870-5-103, Ethernet communication, etc;
