The Best Fluorescent Lifetime Fiber Optic Temperature Sensor for Transformer Winding Temperature Measurement

Penderia suhu gentian optik, Sistem pemantauan pintar, Pengeluar gentian optik yang diedarkan di China

In the power system, maintaining the normal operation of power transformers is the basic guarantee for reliable power supply of the entire system. In recent years, China’s electricity demand has grown rapidly, and the development direction of the power system is towards ultra-high voltage and large capacity. Therefore, the failure rate of transformers has also increased. According to relevant data statistics, the average accident rate of 110kV and above transformers is very high, especially in recent years, the accident rate of insulation aging, transformer winding breakdown, and burning caused by overload operation of transformers is also very high. The life of high-voltage oil immersed power transformers mainly depends on the life of solid insulation (fiber paper), and temperature, moisture, and oxygen are the main factors that promote insulation aging. Thermal effect is the decisive factor of transformer aging, and the hot spot temperature determines the service life of transformers.

The advantages of fiber optic sensors

With the rapid development of optoelectronic technology, the birth of fiber optic sensors has provided a new technological means for transformer temperature measurement. Compared with traditional electrical signal measurement sensors, fiber optic sensors have many advantages such as small size, corrosion resistance, electromagnetic interference resistance, high temperature resistance, and high voltage resistance, which can effectively monitor the hot spot temperature inside power transformers. The most mature technology currently is temperature sensors based on fluorescent fibers, and the most widely used is point type fiber optic temperature measurement products.

The method of temperature measurement for transformer windings

The direct measurement method involves burying sensors near the wire in the winding, and then obtaining the temperature value near the sensor through a detection instrument. It is an online detection device. The direct measurement method can measure the hot spot temperature of the winding in real time and accurately; By starting the refrigeration equipment in a timely manner, accidents caused by overheating of transformer windings can be avoided. The most typical applications of this method are fluorescent fiber optic temperature sensors and semiconductor fiber optic temperature sensors.

Compared with other sensors, factors such as detector degradation, fiber bending, and light source have little impact on the system of fluorescence lifetime type fiber optic temperature sensors. It is easier to correct the sensor probe, and the measurement accuracy and sensitivity are higher in the medium to low range, which is suitable for the requirements of internal temperature measurement in transformers. Currently, fluorescence lifetime type fiber optic temperature sensors are used in the field of transformer winding temperature measurement both domestically and internationally.

Advantages of Fiber Optic Temperature Measurement System for Oil Immersed Transformers

The fluorescence fiber optic temperature measurement system can truly reflect the internal temperature changes of transformers. PT100 can only test the top oil temperature, middle oil temperature, and bottom oil temperature. The theoretically calculated hot spot temperature data has a large deviation and shows a non-linear trend over time, and the time to reach a stable temperature is long, which is not conducive to transformer maintenance. In contrast, the theoretically calculated PT100 oil temperature data is close to the measured PT100 oil temperature data. Walau bagaimanapun, the time required to stabilize the temperature is long, which has a negative impact on transformer maintenance.

The fluorescence fiber optic temperature measurement system for oil immersed transformers introduces fluorescence fiber optic temperature measurement technology into the transformer, achieving distributed online monitoring of the internal temperature of the transformer. It can monitor and locate hot spot temperatures in real time, greatly improving the sensitivity and reliability of detection. The fiber optic winding temperature online monitoring system for transformers can directly, real-time, and accurately measure the winding temperature, achieve internal temperature monitoring of transformers, accurately measure the temperature of transformer windings, control cooling systems such as fans and cooling pumps in real time, greatly extend the service life of power equipment transformers, ensure power supply during peak loads, and reduce unplanned or unexpected accidents to a low degree, thereby improving power production at a low cost and enhancing the safety and reliability of the entire system operation.