The Design And Development Of Transmission Line Sag Measurement System Based On Beidou Localization Technology

As the important and indispensable part of power network, power transmission line is responsible for power transmission. Especially the ultra high voltage transmission line which is the power main trunk line, its reliable and stable operation concerns the development of the national economy. The transmission line sag related to the safety of the whole transmission line is one of the main indexes for the design and operation of the line, so it must be controlled in the allowable range of design requirements. The transmission line operating load and the surrounding environment variation may cause the change of the transmission line sag which may lead to serious security risks if it's too large. Meanwhile, the transmission capacity of the transmission line is limited by sag especially in the crossing, sparsely dense and large span section. Thus, the development of an intelligent high voltage transmission line sag measurement system is of great practical significance.In this paper, the transmission line sag measurement system based on the Beidou Positioning Technology is proposed, and the position information of each point of the transmission line is acquired by the high precision positioning technology of Beidou.Firstly, data is transmitted to the ground monitoring center through the GSM/GPRS/TD-SCDMA/WIFI communication channel and converted, analyzed and calculated by system master station software. Then, curve fitting algorithm based on catenary equation is adopted to build 2D/3D curve model of transmission line according to collected discrete point sets. Finally, sag value is calculated by using the geometric structure based on the built curve model and the purpose of sag measurement is achieved.For the system, environmental temperature and wind speed of the test line can be monitored in real time, and it can build theoretical graphics model and calculate theoretical sag value of the test line according to the theoretical calculation formula of conductor sag and catenary equation. It is more intuitive and convenient to verify the accuracy of the measurement by comparing the line model and theoretical sag value obtained by calculation and measurement.Combined with the practical circumstance high voltage line sag value is measured in real time by the system, so it can greatly reduce the work load of the construction workers, and ensure the safety of the staff while improving the work efficiency.