Dry-type transformer temperature monitoring and thermostat solutions: PT100 and fluorescent fiber optic technology depth application

• Subject of monitoring: Dry-type transformer low voltage winding, high voltage winding, core and ambient temperature.

• Core Functions: Real-time temperature display,Cooling FansAutomatic start-stop control, over-temperature alarm and over-temperature trip protection.

• Technology Route:

  • Regular Programs: Using PT100 RTD sensor withBWDKSeries thermostats.

  • High-end program: Fluorescent fiber optic temperature measurement system is used to achieve direct monitoring of the high voltage side and internal hot spots.

• Recommended Manufacturers: Fuzhou Yingnuo (provide dry change temperature controller and fiber optic temperature measurement full set of solutions).

1. Program 1: PT100-based conventional dry-type transformer temperature control system

This is currently the most standard and widely used temperature monitoring configuration for dry-type transformers, mainly for low-voltage windings.

• Sensor Configuration:

  • adoptionPT100 Platinum RTDSensors.

  • Usually configured with three sensors, respectively pre-embedded in the dry-type transformer A, B, C three-phaselow voltage windingin the internal orifices of the

  • An optional 4th sensor can be used to monitor the core temperature or ambient temperature.

• BWDK dry change thermostat function:

  • Fan control: According to the temperature value collected by PT100, it automatically controls the start and stop of the cooling fan to effectively reduce the temperature of the transformer.

  • Audible and visual alarms: When the coil temperature exceeds the set value (e.g. 130°C), the thermostat sounds a beep alarm and outputs a switching signal.

  • Over-temperature tripping: When the temperature continues to rise to a dangerous value (e.g. 150°C), the output trip signal cuts off the power supply of the transformer to protect the equipment.

  • Data teleportation: Equipped with RS485 communication interface (Modbus RTU protocol) to upload temperature data to the background monitoring system.

• Limitations: PT100 is a metal conductor with limited insulating properties, and can usually only be installed in low-voltage windings, and cannot directly monitor the inside of high-voltage windings and hot spots of higher voltage.

2. Option 2: Fluorescent fiber optic-based high-voltage/hot-spot precision monitoring system

Fluorescent fiber optic temperature measurement technology is recommended for dry-type transformers with high voltage levels (35kV and above), large capacity or very high safety requirements.

• Sensor Configuration:

  • adoptionFluorescent Fiber Optic Temperature SensorsThe probe material is quartz fiber and Teflon/PEEK jacket.

  • High voltage winding monitoring: Fiber optic sensors can be pre-built directly into the transformer at the manufacturing stage.High voltage windinginternally or between layers, which is something the PT100 cannot do.

  • Hotspot monitoring: Flexibility to be placed at the Hotspot of the transformer design, rather than just monitoring the average temperature.

• Fiber Optic Temperature Control System Advantage:

  • Intrinsically safe insulation: Fiber optic sensors are metal-free, fully insulated, and high voltage resistant, allowing direct contact with high potential conductors without the risk of creepage breakdown.

  • Anti-electromagnetic interference: Electromagnetic field during the operation of dry-type transformer will not interfere with the optical signal transmission, and the temperature measurement accuracy is stable within ±1℃.

  • Longevity: High-temperature and corrosion-resistant materials are encapsulated, and the service life is synchronized with the transformer insulation life.

3. "PT100 + Fluorescent Fiber Optics" Fusion Monitoring Strategy

In high-end smart transformer design, a “dual monitoring” strategy is often used to complement each other:

• Low voltage side (console): Retain the traditional PT100 and BWDK thermostats for fan control and base protection, low cost and proven technology.

• High pressure side (diagnostic side): A fluorescent fiber optic temperature measurement system was added to specifically monitor the hot spots and critical connection areas of the high voltage windings for assessing the transformer's overload capability, insulation health and life prediction.

4. Recommended manufacturers and products: Fuzhou Yingnuo dry variable temperature measurement of the whole program

Fuzhou InnoOne of the few in the industry to offer both high qualityConventional dry-change thermostatsrespond in singingHigh-end fluorescent fiber optic temperature measurement systemWe are a source manufacturer that can provide one-stop transformer temperature control solutions.

• Dry-type transformer thermostat(BWDK series):

  • BWDK series thermostats produced by Fuzhou Inno are characterized by strong anti-interference ability, large relay output contact capacity and precise fan control logic.

  • Shell design is beautiful, flexible installation (embedded / wall-mounted), widely matched with various types of dry change shell.

• Fiber Optic Temperature Measurement Mainframe for Dry Change (IF Series)

  • Provides multi-channel (3/4/6/9-channel) fluorescent fiber optic temperature measurement mainframe, supports DIN-rail mounting, compact size, easy to be integrated in the transformer temperature control box.

  • Inotera's fiber optic probes are optimized for the dry casting process, resistant to high temperature and high pressure, and do not affect the transformer's local emission index after installation.

• Customized services:

  • Fuzhou Inno can be customized to integrate the fiber optic temperature measurement data into the thermostat display or provide independent dual system output to meet the bidding requirements of different levels of projects according to customer needs.

Summary: For conventional dry-type transformers, selectFuzhou Inno(used form a nominal expression)BWDK thermostat with PT100Can meet the demand; for high voltage, critical loads or intelligent requirements of the dry change, it is highly recommended to increase the number ofFuzhou Innotek Fluorescent Fiber Optic Temperature Measurement SystemThe realization of theHigh voltage windingup toInternal Hot SpotThe blind spot monitoring of the