What is the best way to monitor the temperature of the main transformer windings?

• Main transformer winding temperature monitoring is the core link to ensure the safe operation of the transformer, the choice of method directly affects the monitoring effect
• The oil-immersed main transformer is recommended to use the thermal simulation principle of the BWR Series of winding thermometers, no need to bury sensors inside the winding
• Dry-type main transformers usually use platinum RTD (PT100) direct temperature measurement scheme
• High-voltage large-capacity main transformer can choose fiber-optic temperature measurement to achieve accurate monitoring of winding hot spots
• The online monitoring system can transmit the temperature data to the monitoring platform remotely, realizing a comprehensive visualization of the operating status of the main transformer.
• Inotera offers a full range of BWR series winding thermometers, winding thermostats and online monitoring products for dry and oil-immersed main transformers.
• At the end of the article with selection advice and contact information, you can directly consult the professional technical team

What is Main Transformer Winding Temperature Monitoring?

Main transformer winding temperature monitoring refers to the technical means of collecting, displaying, recording and controlling the real-time temperature of main transformer winding through sensors and instruments. Winding temperature is one of the core parameters to measure the health of the main transformer operation, the winding insulation will accelerate the aging under the high temperature environment for a long period of time, which will cause the insulation breakdown in serious cases, resulting in major accidents.

A well-developed main transformer winding temperature monitoring system usually consists of the following levels:

• sensor layer: Responsible for converting the winding temperature into an electrical or optical signal that can be recognized by the instrument.
• Instrumentation Control Layer: The thermostat receives the sensor signals and completes the temperature display, fan control and alarm output.
• Data management layerOnline monitoring system uploads temperature data to the monitoring platform, realizing historical records, trend analysis and remote viewing.

The three levels cooperate with each other in order to constitute a real sense of the main transformer winding temperature comprehensive monitoring system.

Why is main transformer winding temperature monitoring so important?

Insulation life is directly related to temperature

Transformer winding insulation materials are extremely sensitive to temperature, sustained high temperature will lead to accelerated decomposition of insulating paper, insulating paint and other materials degradation, significantly shortening the actual service life of the transformer. Effective temperature monitoring and control is to extend the service life of the main transformer is the most direct, the most economical means.

Overheating is the main cause of transformer failure

Transformer failure in a large proportion of winding overheating directly related. The causes of overheating are varied, including long-term overload operation, cooling system failure, cooling channel blockage, internal turn-to-turn short circuit. Real-time temperature monitoring can be the first time to capture the abnormal heating signal, for operation and maintenance personnel to win the disposal time.

Meet the requirements of power operation and maintenance regulations

According to the national power industry regulations, the main transformer must be equipped with winding temperature monitoring and protection devices. Temperature data is also an important basis for transformer condition assessment, maintenance program development, and is an indispensable source of basic data for transformer whole life cycle management.

What is the best way to monitor the temperature of the main transformer windings? Comparison of Mainstream Methods

At present, the main transformer winding temperature monitoring mainly has the following several technical routes, each with its own advantages and disadvantages, applicable to different scenarios, the choice should be combined with the type of main transformer, installation conditions and monitoring accuracy requirements for a comprehensive judgment.

Method 1: Thermal simulation principle temperature measurement (recommended solution for oil-immersed main transformer)

Thermal simulation is currently the most widely used technology in the oil-immersed main transformer winding temperature monitoring program, Inotera BWR-04J/BWR-06 series transformer winding thermometer that uses this principle. Its core working method is: through the current transformer to collect the real-time current information of the transformer winding, combined with the transformer top layer oil temperature data, after accurate calculation to obtain the estimated winding temperature, without the need to bury sensors inside the winding under the premise of realizing the continuous monitoring and control of the winding temperature.

• Precision monitoringAccurate estimation of winding temperatures based on thermal simulation principles, a reliable choice for intelligent operation and maintenance of power systems
• Multiple ProtectionWith hierarchical control of the cooling device function, according to the winding temperature intelligent control of the cooling system operating power; at the same time with over-temperature alarm and trip function, when the temperature rises abnormally in time to warn and trigger the protection action.
• intelligent transmissionSupport the output of current signal to the control room display to realize real-time monitoring and centralized display of temperature data, which is suitable for the informatization management requirements of the intelligent power system.
• high efficiency and energy saving: Effectively reduce transformer energy consumption through precise temperature control and intelligent regulation of cooling devices, in line with the direction of green energy development.
• stable and reliable: High-quality components, excellent electromagnetic compatibility, stable operation in a strong electromagnetic interference environment

The BWR series has a wide range of models, including BWR-04A, BWR-04J, BWR-04AJ, BWR-04Y, BWR-06, BWR-06J, etc., which can be flexibly selected according to the needs of the main transformer and the requirements of the control circuit, and support customized development.

Method 2: Platinum RTD (PT100) direct temperature measurement

Platinum RTDs are the standard solution for temperature monitoring of dry-type transformer windings. the PT100 sensor is embedded directly inside the winding or close to the winding surface and converts the temperature signal into a change in resistance value, which is then transmitted to the thermostat for processing and display.

• vantageMature technology, low cost, easy to install, precision to meet the needs of most dry-type main transformer application scenarios
• Applicable Scenarios: Winding temperature monitoring for all types of dry-type transformers, a standard solution for dry-type main transformers
• caveat: Sensor leads need to be insulated and pre-installed at the transformer manufacturing or overhaul stage.

Method 3: Fiber optic temperature measurement

Fiber-optic temperature measurement technology through the fiber-optic sensors laid in the winding internal, the use of light signal temperature response characteristics to achieve temperature measurement, completely free from electromagnetic interference, is a high-voltage, large-capacity main transformer winding hotspot temperature monitoring of the preferred solution.

• vantage: Strong resistance to electromagnetic interference, good insulation, can measure the temperature of hot spots inside the winding, fast response time
• Applicable Scenarios: Large main transformers, converter transformers, applications requiring high accuracy of hot spot temperature
• caveat: Sensors need to be pre-buried at the transformer manufacturing stage, with high retrofit costs at a later stage.

Method 4: Infrared thermal imaging temperature measurement

Infrared thermal imaging is used to scan the transformer shell, joints, bushings and other parts of the transformer through non-contact thermal imaging to quickly find surface temperature anomalies, and is usually used for regular inspections rather than continuous online monitoring.

• vantageNon-contact measurement, scanning of multiple areas simultaneously, visualization of heat distribution images
• Applicable Scenarios: Supplementary means of periodic inspection of external transformer joints, bushings, radiators, etc.
• caveat: The internal temperature of the winding cannot be measured directly, but is usually used as an auxiliary means of detection in conjunction with other monitoring methods.

Comprehensive recommendations: selection of the most suitable program by type of main transformer

The oil-immersed main transformer is recommended to use the thermal simulation principle winding thermometer represented by BWR-04J/BWR-06, together with the oil surface thermostat to form a complete temperature monitoring and protection system; the dry-type main transformer is recommended to use the PT100 sensor with theDry-type transformer thermostatHigh-voltage large-capacity main transformer can be superimposed on the basis of the above program fiber optic temperature measurement; at the same time supplemented by regular infrared thermal imaging inspection of external weak points for additional investigation. A variety of means to cooperate with each other, in order to truly realize the main transformer winding temperature comprehensive, reliable monitoring.

How to choose a main transformer winding thermostat and monitoring system?

Define the type of main transformer and sensor interface

Dry-type main transformer is usually equipped with PT100 platinum RTD sensors, corresponding to the selection of dry-type transformer temperature controller; oil-immersed main transformer is recommended to use the BWR series of thermal analog winding thermometers, combined with the top layer of oil temperature and winding current data to achieve a more accurate estimation of the winding temperature. Before selecting the type, be sure to confirm the main transformer type and the existing sensor interface to ensure that the equipment is fully compatible.

Confirmation of control outputs and alarm requirements

According to the siteCooling FansThe number of groups and control logic, select the thermostat model with the corresponding number of control outputs. At the same time to confirm whether the need for over-temperature alarm, over-temperature trip and other protection contact output, as well as the type of contact and capacity requirements.

Evaluate the need for communication telematics

If the main transformer is connected to the substation automation system, energy management platform or centralized monitoring system, it is necessary to choose a thermostat model that supports current signal output or communication protocol to ensure that the temperature data can be uploaded to the supercomputer system in real time.BWR-04J supports the output of standard current signals, and it can be directly connected to the control room display and monitoring system.

Consider whether to upgrade to an online monitoring system

For the important main transformer with high operation and maintenance requirements, it is recommended to access the transformer online monitoring system on top of the basic temperature controller to realize the comprehensive monitoring and intelligent analysis of multi-dimensional data such as winding temperature, core temperature, load trend, partial discharge, etc., so as to truly realize the comprehensive visual management of the main transformer's operation status.

Inotera Main Transformer Winding Temperature Monitoring Product Solutions

Inotera (Fuzhou) Sales Co., Ltd. provides a complete winding temperature monitoring product system covering dry-type main transformers and oil-immersed main transformers, and can provide a full range of solutions from basic temperature control to intelligent on-line monitoring according to the actual needs of users.

• BWR-04J/BWR-06 Series Transformer Winding ThermometerAdopting thermal simulation principle, it is suitable for oil-immersed main transformer, supporting graded cooling control, over-temperature alarm and trip, and current signal remote transmission, the models cover BWR-04A, BWR-04J, BWR-04AJ, BWR-04Y, BWR-06, BWR-06J and so on, and support customized development, see details. product page
• Dry main transformer thermostat::BWDK Series, IB series and other models, support multiple PT100 sensor input, fan control, over-temperature alarm and RS485 communication remote transmission.
• BWY Series oil level thermostat: Used in conjunction with BWR series winding thermometers to form a complete temperature monitoring and protection system for oil-immersed main transformers.
• Transformer online monitoring systemSupports multi-parameter integrated monitoring of winding temperature, core temperature, partial discharge, load trend, etc., with data uploaded to the monitoring platform in real time.
• Cooling Fan MatchingGFDD top-blowing and GFD side-blowing cooling fans are linked with the thermostat to ensure efficient operation of the cooling system.

Frequently Asked Questions (FAQ) on Main Transformer Winding Temperature Monitoring

Q: What is the difference between BWR-04J and ordinary thermometer? Why is the thermal simulation principle used for oil-immersed main transformers?

A: Ordinary thermometers directly measure the actual temperature at a fixed point, while BWR-04J is based on the principle of thermal simulation, through the collection of winding current and top oil temperature two signals, after calculating the estimated value of temperature rise of the winding, which can more realistically reflect the thermal state of the winding, especially suitable for oil-immersed main transformers to achieve continuous monitoring of the temperature of the winding without dismantling the equipment.

Q: When replacing the main transformer winding thermometer, must the new product match the original model?

A: Not necessarily. As long as the sensor interface type, control output circuit and signal type are compatible, the same type of product can usually be used as a replacement. It is recommended to provide the brand and model of the original thermometer and the nameplate information of the main transformer, and place the order after the professional technician confirms the compatibility, in order to avoid purchasing mistakes.

Q：How can the current signal output of BWR series thermometer be connected to the monitoring system?

A: BWR-04J supports the output of standard DC current signals, which can be directly connected to the display instruments in the control room or the upper computer monitoring system. Please refer to the product manual for specific wiring and signal specifications, and if you have any questions, please contact the technical support team of InnoTech for remote guidance.

Q: What customization needs does Inotera's BWR series support?

A: Innotransformer supports customized development according to customer needs, including special model adaptation, adjustment of the number of control circuits, and change of signal output type. Customers with customization needs can directly provide transformer nameplate information and specific requirements, and the technical team will evaluate and issue customized solutions.

Q: What is the product warranty period and after-sales service?

A: Inotera products provide standard warranty service, free repair or replacement of non-man-made damage during the warranty period, while long-term guarantee of spare parts supply. Specific warranty terms to the purchase contract shall prevail, for details, please consult the sales consultant.

Contact Inotera today for main transformer winding temperature monitoring solutions!

Whether you are a new project supporting the selection, or the existing main transformer temperature monitoring system for upgrading and transformation, Inotera's professional technical team will provide you with accurate and efficient selection recommendations and complete product offer. Welcome to contact us through the following ways:

• Contact Phone / Wechat13959168359
• Company Email：2969488289@qq.com
• Company Address: U Valley-Internet of Things Industrial Park, Fuzhou, China
• Product Center:: https://www.innotd.com/products

Safe operation of main transformers starts with accurate winding temperature monitoring. Innotransformer, your trustworthy professional supplier of transformer auxiliary equipment.

statement denying or limiting responsibility

The content of this article is for reference only, and is intended to provide a general introduction to the knowledge related to the temperature monitoring of main transformer windings, and does not constitute any form of engineering design recommendations or technical commitments. The monitoring methods, product functions and applicable scenarios described in this article are generalized descriptions, and the actual product specifications and technical indexes are subject to the product manuals, technical documents and contractual agreements formally provided by Inotera (Fuzhou) Sales Co. In the actual project, the design, equipment selection, installation and commissioning as well as operation and maintenance of the main transformer winding temperature monitoring program should be carried out by qualified professionals in accordance with the current national standards and industry norms. If you need to get accurate product technical information, please directly contact the professional technical team of Innotranslate.