Research And Design Of Aeolian Vibration Monitoring System On Overhead Transmission Lines

Aeolian vibration on transmission lines is very easy to cause destruction to transmission conductor and electric power fittings, which poses a serious threat to the safeoperation of power system. With the rapid increasing of the electrical transmissioncapacity and conveying distance, the diameter and weight per unit length of thetransmission line are increased somewhat,as well as the height of suspension point,all these make aeolian vibration more likely to happen. The damage ofaeolian vibration is formed by accumulating for a long time, possesses strongconcealment, and it can’t be true by observing directly. Therefore, power sectors startto put on-line monitoring device of aeolian vibration into use to achieve the vibrationstate and the level of fatigue. However, the on-line monitoring devices which havebeen applied at present always existing problems like power supply, communication,unstabitily of device and other shortages due to the complex operating environment ofthe transmission lines. Especially to the monitoring unit installed on the lines, thepower supply and communication become the focus in the industry.Based on the current on-line monitoring technology of aeolian vibration, thispaper has designed an aeolian vibration system for on-line monitoring, which includesintelligent monitoring terminal that is consisted of conductor monitoring unit andtower monitoring unit, the condition monitoring agent and master station system.Among them, conductor monitoring unit installed on the lines is to achieve vibrationamplitude、frequency、conductor temperature and calculate dynamic bending strain ofthe clamp at the outlet, the data is sent by Zigbee to the tower monitoring unit. Thetower monitoring unit which is set up on the tower does the real time supervision ofthe weather and environmental conditions for the monitoring places, then stores thedata and information those have got from the conductor monitoring unit, all of themeasuring results will be transferred to the condition monitoring agent(CMA) bycommunication modes like Ethernet, WIFI.GPRS and so on. After the messages fromthe condition monitoring agent(CMA) have been transmitted to master station systemand received by condition acquisition gateway(CAG),the master station system willestimate fatigue degree of the lines with the vibration information within a while andthe dynamic bending strain, also do supplementary policies according to other factorsthose may affect conductor vibration.This article mainly introduces the design of intelligent monitoring terminal,including structure design, power design, sensor design and model selection, signalprocessing methods and software design of conductor monitoring unit. In addition, thewhole project has overcome the power supply problem of the traditional on-linemonitoring effectively and can measure the amplitude, frequency and dynamicbending strain of aeolian vibration on the lines accurately.This paper has finished the trial of the method that takes power from electronic transformer, estimating the measurement accuracy of the aeolian vibration andconductor temperature, also done the communication test between conductormonitoring unit and intelligent monitoring terminal. The results have shown：(1) thepower circuit of conductor monitoring unit can work well when conductor current isbetween30A~600A,but it can’t continue running until the current through the wireswhich has been more than600A is down to meet the requirements;(2) Conductormonitoring unit reverts the amplitude of conductor vibration exactly by means ofsignal acquisition of the cantilever beam-displacement sensor and signal processingby MSP430F1611;(3)The conductor monitoring unit is able to measure the wiretemperature well and truly with calibration of temperature transducer;(4)It is stablefor the communication between the conductor monitoring unit and the intelligentmonitoring terminal.