Dynamic Line Rating System For Overhead Transmission And Its Application Analysis

Electric power construction and Electric demand are growing explosively now in China. Dynamic can solve the electric power transmission"bottleneck"to a large extent on the basis of original lines. And it also can ease the contradiction between power supply and demand. Thus technology has a good market prospect and a great economic benefit.The theoretical calculation methods of dynamic line rating (DLR) system are expounded. Weather model and conductor temperature model for calculating dynamic line rating is raised. This paper analyses the computation method for strain sag of transmission line. Besides, the fitting result between strain tension and conductor temperature and how to decrease the fitting error is discussed in the paper.This paper lucubrates the wireless communication method between DLR data acquisition terminal and monitoring station, realization of data transmission by GPRS and PDU-standard coded SMS data transmission based on G24 module. 7-bit, 8-bit and data transmission plan are mainly explained. Chinese SMS encoding and decoding method for data acquisition terminal are also accomplished. In the paper, the calculation model and assessment method for transmission line transient capacity are proposed. The time of Conductor temperature rising when transmission line capacity changes suddenly, transient capacity for a certain interval and the remaining time for a certain current are also analyzed. Furthermore, the model is proved to be correct based on the field operational data.Finally, Analysis on the operational data shows that the system can monitor the actual line working conditions with great steady and reliability and thus can improve the capacity of the transmission line effectively.