Research Of On-line Monitoring Device Of Capacity-increasing System On Overhead Power Transmission Lines

With the development of economy and the increasing demand for electricity,the bottleneck problem of transmission capacity has become increasingly prominent.How to make use of the existing transmission lines to solve this problem,become one of the main problems.So,Dynamic Rating System has been proposed.The essence of Dynamic Rating System is to fully tap the potential of the transmission line.At present,the reliability of the on-line monitoring devices of dynamic capacity increase are poor,and the service life is short,so that the application of large area cannot be realized.Based on Dynamic Rating System we have invented,the reliability of the monitoring system is analyzed,and the device is improved and upgraded.It makes it possible for large-scale application.The control module of the Dynamic Rating System device is subjected to the accelerated reliability test in this paper.And the reliability analysis is carried out.Finally we obtain the data of reliability and life of the device.In this paper,the problems of large volume and heavy weight of the device's power have been solved.The Mn Zn magnetic core is replaced by Fe-based amorphous cores.The power we designed not only can meet the requirements of the device,but also the size of the power supply is reduced to about 47%,and the weight is reduced to about 69%.Starting current(the minimum transmission line current which can make the monitoring device work)is reduced from 75 A to 50 A.In this paper,based on the monitoring data of field trial operation,the nonlinear equation for calculating the maximum carrying capacity is derived.Through the verification,the model can greatly reduce the error brought by the system and the measurement,improve the accuracy of the prediction of the maximum carrying capacity,and provide reliable data support for the safe operation of the transmission line.Other modules of the device have been improved and upgraded in this paper.The existing communication module is replaced by a more advanced and reliable communication module.Angle sensor is replaced by new sensor which have advantages of low operating voltage(5V)and better dynamic performance.