Types Of Power Lines Research Articles

A point cloud segmentation method for power lines and towers based on a combination of multiscale density features and point-based deep learning

ABSTRACT The point segmentation of power lines and towers aims to use unmanned aerial vehicles (UAVs) for the inspection of power facilities, risk detection and modelling. Because of the unclear spatial relationship between the point clouds, the point segmentation of power lines and towers is challenging. In this paper, the power line and tower point datasets are constructed using Light Detection and Ranging (LiDAR) and a point segmentation method is proposed based on multiscale density features and a point-based deep learning network. First, the data are blocked and the neighbourhood is constructed. Second, the point clouds are downsampled to produce sparse point clouds. The point clouds before and after sampling are rotated, and their density is calculated. Next, a direct mapping method is selected to fuse the density information; a lightweight network is built to learn the features. Finally, the point clouds are segmented by concatenating the local features provided by PointCNN. The algorithm performs effectively on different types of power lines and towers. The mean interaction over union is 82.73%, and the overall accuracy can reach 91.76%. This approach can achieve the end-to-end integration of segmentation and provide theoretical support for the segmentation of large scenic point clouds.

Effect of Power Line Type on The Safety of Transmission Tower

The supply of electricity is directly affected by the structural safety of transmission tower. The unsuitable power line type can impose extra forces on transmission tower. The failure within transmission tower results in power outage because the designed power transmission tower cannot bear the extra force loading. In this paper, the mechanical responses in transmission tower with different power line types were calculated by means of finite element software. Commercial software Abaqus was employed for analyzing the structural safety of transmission tower. Ten kinds of power line were chosen to impose static forces on transmission tower. Based on the finite element results, the maximum stress and displacement were obtained. When the dimension of power line is less than a certain value, the transmission tower is safe; otherwise, the transmission tower may collapse.

Comparison of electromagnetic fields emitted by typical overhead power line towers

The problem of electromagnetic fields produced by overhead power lines is still a widely discussed topic. These concerns itself are coming not only from the power line designers, but also from general public sector. Therefore, the topic can be separated into two different areas of interest: health concerns and technical problems. Conducted discussion and research regarding electromagnetic field’s health risks to general public led to creation of legislative time restrictions and absolute value limits for low-frequency electromagnetic fields. On the other hand, technical side of problem is mostly connected with electromagnetic induction in connection with surrounding objects around power lines. Still, precise calculations are needed for both of these areas of interest. The aim of this article is to carry an analysis comparing various electromagnetic fields emitted from basic types of power lines in 2D space. Comparison is made for the worst-case scenarios and for different sets of boundary conditions. The paper also shows the marginal difference of EMF generally emitted by EHV and HV systems. To achieve the most precise results, an integral–differential EMF calculation methodology is introduced and implemented into software interface. Final results are applicable in overhead lines design and planning process and are also suitable for future research of overhead power lines.

Life Cycle Cost Analysis of Three Types of Power Lines in 10 kV Distribution Network

There are three types of power lines in the 10 kV distribution network in China, i.e., copper power cables, overhead power conductors and aluminum alloy power cables. It is necessary to give a comprehensive evaluation to choose the type of power line in some delicate practical engineering. This paper presents a life cycle cost (LCC)-based analysis method for the three types of power lines. An LCC model of the power line in the 10 kV distribution network is established, which considers four parts: investment cost, operation and maintenance cost, failure cost and discard cost. A detailed calculation model for the four parts is presented, and to calculate the failure cost, the Monte Carlo algorithm is employed to simulate the values of expected energy not supplied (EENS). Two practical 10 kV power line projects in Fujian Province in China were analyzed based on the proposed LLC model and corresponding developed software, which has helped the power company select the appropriate power line successfully.

Planning of Low-Voltage Distribution Networks Using Hierarchical Methods

Low-voltage distribution networks represent a component of the power system with the most prominent problems in terms of voltage quality and losses of electrical power which is delivering to the end customers. Overcoming of such problems is a real challenge for distribution companies, since they are obliged to deliver electricity of standard quality to the end customers, but at the same time taking care of their own interests. In this paper, a method based on hierarchical algorithms applicable in the planning of low-voltage distribution networks is presented. The planning of such networks includes determining of an optimum location of substation, radial network configuration, as well as appropriate types of power lines, all in order to achieve the prescribed voltage levels and minimize the power losses in electricity transmission.

Wire Marking Results in a Small but Significant Reduction in Avian Mortality at Power Lines: A BACI Designed Study

BackgroundCollision with electric power lines is a conservation problem for many bird species. Although the implementation of flight diverters is rapidly increasing, few well-designed studies supporting the effectiveness of this costly conservation measure have been published.Methodology/Principal FindingsWe provide information on the largest worldwide marking experiment to date, including carcass searches at 35 (15 experimental, 20 control) power lines totalling 72.5 km, at both transmission (220 kV) and distribution (15 kV–45 kV) lines. We found carcasses of 45 species, 19 of conservation concern. Numbers of carcasses found were corrected to account for carcass losses due to removal by scavengers or being overlooked by researchers, resulting in an estimated collision rate of 8.2 collisions per km per month. We observed a small (9.6%) but significant decrease in the number of casualties after line marking compared to before line marking in experimental lines. This was not observed in control lines. We found no influence of either marker size (large vs. small spirals, sample of distribution lines only) or power line type (transmission vs. distribution, sample of large spirals only) on the collision rate when we analyzed all species together. However, great bustard mortality was slightly lower when lines were marked with large spirals and in transmission lines after marking.ConclusionsOur results confirm the overall effectiveness of wire marking as a way to reduce, but not eliminate, bird collisions with power lines. If raw field data are not corrected by carcass losses due to scavengers and missed observations, findings may be biased. The high cost of this conservation measure suggests a need for more studies to improve its application, including wire marking with non-visual devices. Our findings suggest that different species may respond differently to marking, implying that species-specific patterns should be explored, at least for species of conservation concern.

Evaluating transmission towers potentials during ground faults

During ground faults on transmission lines, a number of towers near the fault are likely to acquire high potentials to ground. These tower voltages, if excessive, may present a hazard to humans and animals. This paper presents analytical methods in order to determine the transmission towers potentials during ground faults, for long and short lines. The author developed a global systematic approach to calculate these voltages, which are dependent of a number of factors. Some of the most important factors are: magnitudes of fault currents, fault location with respect to the line terminals, conductor arrangement on the tower and the location of the faulted phase, the ground resistance of the faulted tower, soil resistivity, number, material and size of ground wires. The effects of these factors on the faulted tower voltages have been also examined for different types of power lines.

Power lines, viruses, and childhood leukemia

Mr Sahl hypothesizes' in the May (5:3) issue of CCC that viral contacts may explain reported associations between childhood leukemia and residential proximity to high voltage power lines. Although a viral etiology of leukemia has been of interest for some time2 and warrants more refined study, it seems unlikely that confounding from viral exposures has an impact on the reported associations between magnetic fields and cancer or that the literature on wire codes and magnetic fields has relevance to the viral hypothesis. Before addressing his key argument, some clarification is necessary: (i) Studies of childhood cancer and residential magnetic fields are not concerned, with the exception of the Nordic studies,3 with exposure from hightension power lines. Studies in urban communities4 are based on whatever types of power lines are near the home, with virtually all classified based on nearby, ordinary low-voltage distribution-lines. A more refined wire code7 gave less, not more, emphasis to the few homes near high tension lines since High Wire Code comprised a broader group than the Very High Current Configuration category used in previous studies; (ii) While the cancer associations based on wire codes have been stronger than those based on measured fields, there are theoretical reasons (accurately stated by Mr Sahl) that make the superiority of one versus the other as a marker of historical exposure uncertain. It should be noted that no study, to date, has had a sufficiently comprehensive set of field measurements to provide strong evidence for or