Study And Design Of The Sag Monitoring Device Of Power Wires And The Breeze Vibration Monitoring Device Of Power Transmission Under The Condition Of Low-temperature Operation

With the development of science and technology,the traditional power system fault detection has changed from outage maintenance to on-line monitoring.Under low temperature environment,the common on-line monitoring device has high false alarm rate,frequent faults and low reliability,which makes the monitoring device lose its basic functions and cannot meet the ever-changing requirements of power system development.At the same time,the application of on-line monitoring device in low-temperature environment is restricted by the lack of low-temperature power supply.In this paper,two methods of on-line power supply and low-temperature battery are studied to improve the reliability of power supply,First of all,the energy acquisition module is designed by analyzing the distribution characteristics of magnetic field.Secondly,the conditioning scheme of the secondary side supply circuit is designed after studying the impact of qualified width of air gap in the magnetic core material on the draw-out power coil.To improve the reliability of the power system,the author has studied how to use the low-temperature battery as backup power for the whole condition monitoring device in this paper.The low temperature performance of the battery is significantly improved by adding appropriate amount of lithium vanadium phosphate and its composite materials into the energy storage battery,thus ensuring the power supply for the reliable operation of the monitoring system in a low-temperature environment.Moreover,the author has also studied the relationship between low temperature and the selection of condition monitoring threshold.For the equipment with significant influence at low temperature,the author has adopted the methods of setting the dynamic threshold according to temperature,combined early warning of temperature parameter and modifying the early warning criterion under low temperature condition,so as to improve the practicability of condition monitoringand diagnosis method of power transmission and transformation equipment under low temperature condition.The MTBF(mean time between failures)of normal temperature conductor sag monitoring device in low temperature area is 25,773 hours,while that of low temperature conductor sag monitoring device in low temperature area is 62,808 hours;the MTBF of normal temperature conductor aeolian vibration monitoring device in low temperature area is 26,178 hours,while that of low temperature conductor aeolian vibration monitoring device in low temperature area is 63,205 hours.All of these results indicate that the technology and method to improve low-temperature reliability are effective,and MTBF of each device is significantly enhanced after the low-temperature reliability is improved.