Design Of An On-Line Measurement System For Tower Grounding Resistance Based On Wireless Sensor Network

At present,as China’s transmission line network becomes more and more complex,new requirements are put forward for the safe,reliable and efficient operation of the power system.Among them,the grounding safety performance of line tower has become an important factor affecting the operation reliability of power system.The existing methods for measuring the grounding resistance of towers have different application defects in remote mountainous areas.Therefore,it is necessary to further study the measurement method of tower grounding resistance,and study and design a grounding resistance measurement system that can realize remote automatic measurement.In this paper,the methods of grounding resistance measurement of existing towers are comprehensively studied,and the shortcomings and defects of existing measurement methods are analyzed.A linear tower grounding resistance measurement system based on wireless sensor network was designed.The article mainly contains three aspects.This method comprehensively uses clamp meter method,wireless sensor network,multi-point measurement to improve accuracy and other technologies,which can realize the remote and accurate measurement of the grounding resistance of the tower.Firstly,the theoretical model of measuring grounding resistance by clamp meter method is simulated by MATLAB,and the theoretical calculation formula for calculating grounding resistance is analyzed.Algorithms to improve measurement accuracy are analyzed,especially how to accurately measure ground resistance parameters at large measurement data.Then,the design methods and parameters of the sensor,including voltage transformer and current transformer,were simulated and analyzed using Saber software.Finally,a comprehensive measurement scheme of this system is proposed.The hardware circuit of the tower grounding resistance measurement system based on the wireless sensor network was constructed.The circuit includes voltage transformer and its driving circuit,current transformer and its detection circuit,CC 2530 wireless sensor network circuit,GD32F303 processor circuit and NBIOT data return circuit.The use of CC2530 wireless sensor network to realize the automatic networking of each test point close to the distance,and then through a coordinator with NBIO T for data calibration and backhaul,data calibration to improve measurement accuracy,data backhaul is to transmit the measured data back to the server,to achieve remote monitoring of measurement data.Software code was written.The software code mainly has three parts: the coordinator software code with NBIOT,which summarizes the collected CC2530 terminal measurement data and runs the algorithm to improve accuracy,and transmits the measured parameters back to the server;CC2530 terminal measurement code realizes single-point ground resistance measurement,including sinusoidal signal transmission and current filter detection algorithms;Server data transmission and reception,can detect the measured ground resistance value in real time.Finally,the functional test of the system software and hardware is carried out,and the test results show that the established technical objectives are achieved,and part of the practical application work is carried out.