On-line Monitoring of Charge Unit by Using Fiber Bragg Grating Temperature Sensors

The charge unit supply power when the power is cut off It has been the necessary components in every type of substations to ensure the continuous operations of electric relays, automatic devices and circuit breakers. By using contacting electrical insulating Fiber Bragg Grating temperature sensor, the monitored equipment can be measured and controlled under the safe temperature. The temperatures of three fans and environment have been surveyed since June 6, 2010, in the charge unit of Yanjin substation's main control room. The real-time monitoring of 24-hours indicates that the temperature changes in the range of 1 degrees C. At the long-term of 479 days, the average daily minimum temperature range of three fans is 12.48 degrees C, and the maximum range is 23.07 degrees C. The maximum temperature is 39.14 degrees C on April 30, 2011, and the minimum temperature is 23.98 degrees C on January 10, 2011. The daily average of ambient temperature range is 12.04 degrees C, the maximum temperature is 38.38 degrees C on July 16, 2010, and the minimum temperature is 26.34 degrees C on January 9, 2011. The maximum difference between the temperature of fan and the ambient temperature is 7.60 degrees C on October 23, 2010. According to the relevant standards and monitoring results, the maximum threshold of fan temperature is defined to 85 degrees C, and the threshold of temperature rise is 20 degrees C.