Quasi-distributed Overhead Transmission Line Ice Monitoring Simulation Analysis

In recent years, the power demand in China has increased dramatically along with the rapid growth of the national economy. Since the distributions of the power resources are extremely uneven in our country, the power energy transmission mainly rely on network transmission lines by reference to related technology, economy and environment pollution. The safety of operation of power transmission lines which serves as a significant part of power network, has attractive to more and more researchers in the fields of power system operation, management and scientific research and made great achievements in the monitoring technique for power transmission lines.In the paper, the potential damages casued by the cladding ice in the overhead transmission lines and the current insufficient cladding ice monitoring methods based on the condition that the cladding ice is assumed to be evenly distributed are firstly introduced. Then the fiber optic sensors are proposed to provide an innovative way for cladding ice monitoring because of their obvious advantages comparing to conventional sensors, e.g., anti-electromagnetism interference, high precision, long distance transmission, adapting to bad environment, convenient installation, etc.In Capter Two, the "catenary" theory is briefly ,described with some related calculations of uniform cladding ice loads in the transmission lines presented. the distributed measuring ideas and finite element theory are firstly proposed to apply in the operation condition monitoring for the transmission lines. Based on the integrated combination of the above two theoretical methods, an innovative algorithm is proposed by the author to calculate the possible sag by reference to several stress data. The proposed innovative algorithm is based on the assumption that the cladding ice load is evenly distributed between arbitrary two monitoring points in the whole transmission lines. The corresponding GUI design in Matlab software is successfully completed in the paper with simulation reslut verifying the feasibility and practicality of the proposed algorithm.In Capter Three, the simulation models of the overhead transmission lines are established by using ANSYS software, with two practical exmples of 900m equal-height and 1000m unequal-height ransmission lines presented. The even cladding icing loads and uneven cladding icing loads are chosen to simulate the analyze the performance of the developed simulation models. The whole cladding icing monitoring scheme is also proposed and designed based the simulation results for building a practical monitoring system.In Capter Four, a potential conductor dancing calculation sheme is proposed based on the above cladding icing calculation and analysis, which lays the innovative theoretic foundation for the future research works. The calculation error of the original algorithm is limited to 6% according to the verifications of several arbitrary load conditions. The improved algorithm in the paper has better performance with its calculation error limited to 3% comparing to the original algorithm.