Operation Status Monitoring of Transmission Tower in Power System based on Data Fusion

This paper studies the application of data fusion technology in power system to solve some difficult problems in this complex energy system. A transmission tower identification and bird nest detection method based on corner, line, color and shape features is proposed. Through LSD (Line Segment Detection) and Harris corner detection method, the straight line segment and corner point in the image are extracted respectively. Combined with triangle method, the actual tilt angle of tower is measured; According to the nesting rule of birds in transmission towers, the basic unit segmentation algorithm of transmission towers is proposed, and the basic unit segmentation of transmission towers is realized by using the local maximum of the target pixel row statistical histogram. The algorithm proposed in this paper can effectively solve the problems of on-line measurement of tilt angle of transmission tower and on-line detection of bird's nest, which will lay a theoretical foundation for on-line monitoring of transmission tower status.

Bearing Capacity Analysis of Transmission Tower Structure Considering Corrosion Damage

As an important part of power grid equipment, transmission towers are in direct contact with the external environment for a long time. As a coastal city in China, Fujian has been affected by marine environment and industrial pollution for a long time, which directly affects the safety of transmission towers in long-term service. In order to explore the changes of the ultimate bearing capacity of the tower structure after corrosion, this paper uses finite element software to analyse the mechanical properties of the tower structure during long-term service, and finds that the 45° wind direction is the control condition, and the overall stiffness of the tower decreases with the growth of corrosion time, and the increment of tower top displacement reaches 7% at 12 years of corrosion. The corrosion-sensitive members of the tower were clearly identified, and their stress ratios increased from 0.78, 0.79, and 0.83 to 0.97, 0.98, and 0.99, respectively, at 12 years of corrosion.

As Ruínas do Sumaré

A proposta deste artigo é discutir a relação entre infraestrutura e arruinamento a partir de uma investigação centrada no Morro do Sumaré. Localizado no Parque Nacional da Tijuca, Rio de Janeiro, tem sua realidade inserida em uma relação conflituosa entre a administração do Parque e as empresas de telecomunicação que ali operam cerca de 18 torres de transmissão. Historicamente, o Sumaré é marcado por dois movimentos: primeiro de ocupação, iniciado nos anos 1950, e segundo de remoção, um “ordenamento” implementado desde 1981 com o objetivo de preservar a floresta. Tendo como pano de fundo aspectos correlacionados à obsolescência de infraestruturas decorrentes do avanço tecnológico, ao mesmo tempo que mobilizando especificamente a ideia de paisagem como agente cultural, o trabalho procura discutir estratégias de ocupação no âmbito do projeto. A apropriação de infraestruturas obsoletas é estabelecida como contraposição ao padrão de apagamento da memória urbana, decorrente de uma atitude preservacionista em relação à paisagem, que, em diversas situações, denota certo anacronismo frente à realidade das cidades contemporâneas. Palavras-chave: Paisagem; Infraestrutura; Ruína; Memória Urbana; Sumaré. Abstract The purpose of this article is to discuss the relationship between infrastructure and ruin based on an investigation centered at Morro do Sumaré. Located in the Tijuca National Park, Rio de Janeiro, the site is characterized by a conflicting relationship between the park administration and the telecommunications companies that operate around 18 transmission towers there. Historically, Sumaré is marked by two movements: first, of occupation, beginning in the 1950s, and second, of removal, an “ordering” that has been implemented since 1981 to preserve the forest. The research sought to understand aspects related to the obsolescence of infrastructure resulting from technological advances, applying the concept of landscape as a cultural agent. Moreover, the work seeks to discuss occupation strategies in terms of design based on the concept of appropriation of obsolete infrastructures. It is an opposition to a pattern of erasure of urban memory resulting from a preservationist attitude that in several situations involves a certain anachronism in the face of the reality of contemporary cities. Keywords: Landscape; Infrastructure; Ruin; Urban Memory; Sumaré.

Weight optimization of steel lattice transmission towers based on Differential Evolution and machine learning classification technique

Transmission towers are tall structures used to support overhead power lines. They play an important role in the electrical grids. There are several types of transmission towers in which lattice towers are the most common type. Designing steel lattice transmission towers is a challenging task for structural engineers due to a large number of members. Therefore, discovering effective ways to design lattice towers has attracted the interest of researchers. This paper presents a method that integrates Differential Evolution (DE), a powerful optimization algorithm, and a machine learning classification model to minimize the weight of steel lattice towers. A classification model based on the Adaptive Boosting algorithm is developed in order to eliminate unpromising candidates during the optimization process. A feature handling technique is also introduced to improve the model quality. An illustrated example of a 160-bar tower is conducted to demonstrate the efficiency of the proposed method. The results show that the application of the Adaptive Boosting model saves about 38% of the structural analyses. As a result, the proposed method is 1.5 times faster than the original DE algorithm. In comparison with other algorithms, the proposed method obtains the same optimal weight with the least number of structural analyses.

Active Vibration-Based Condition Monitoring of a Transmission Line

In the power system, the transmission tower is located in a variety of terrains. Sometimes there will be displacement, inclination, settlement and other phenomena, which eventually lead to the collapse of the tower. In this paper, a method for monitoring the settlement of a transmission tower based on active vibration response is proposed, which is based on the principle of modal identification. Firstly, a device was designed, which includes three parts: a monitoring host, wireless sensor and excitation device. It can tap the transmission tower independently and regularly, and collect the vibration response of the transmission tower. Then, vibration analysis experiments were used to validate the horizontal vibration responses of transmission towers which can be obtained by striking the transmission towers from either the X direction or Y direction. It can be seen from the frequency response function that the natural frequencies obtained from these two directions are identical. Finally, the transmission tower settlement experiment was carried out. The experimental results show that the third to fifth natural frequencies decreased most obviously, even up to 2.83 Hz. Further, it was found that under different conditions, as long as the tower legs adjacent to the excitation position settle, the natural frequency will decrease more significantly, which is very helpful for engineering application.

Seismic Response Mitigation of a Television Transmission Tower by Shape Memory Alloy Dampers

High-rise television transmission towers are of low damping and may vibrate excessively when subjected to strong earthquakes. Various dynamic absorbers and dampers are proposed to protect television transmission towers from excessive vibrations and damages. Up to now, the seismic damage reduction in television towers, using SMA dampers under seismic excitations, has not been conducted. To this end, the response reduction in a flexible television tower, disturbed by earthquakes using SMA dampers, is conducted in this study. A two-dimensional dynamic model is developed for dynamic computation at first. The mathematical model of an SMA damper is proposed, and the equations of motion of the tower, without and with, are established, respectively. The structural dynamic responses are examined in the time and the frequency domain, respectively. The effects of damper stiffness, service temperature, hysteresis loops, and earthquake intensity on control efficacy are investigated in detail. In addition, the power spectrum density curves, of dynamic responses and the energy responses, are compared to provide deep insights into the developed control approach. The control performance of SMA dampers is compared with that of widely-used friction dampers. The analytical observations indicate that SMA dampers with optimal parameters can substantially reduce the vibrations of TV transmission towers under seismic excitations.