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Preventing Bird Streamer Outages Using Alternative Tower Configurations
Abstract
This paper presents methods for mitigating the destructive impact of bird excrement contamination on 110 kV power lines. In addition to the typical retrofitting techniques (cover-ups and perch management), focus is mainly on reconfiguration and alternative tower designs aimed at eliminating streamer outages. Advantages and disadvantages of existing designs are assessed and novel ideas are presented by the authors.
... Studies [45] on vertically suspended composite insulators show that corona rings installed at the conductor end increase the probability of bird streamer-caused flashover, as they extend the electrical 'reach' of the conductor. Corona rings installed on the line end of the insulator string in the V-string configuration increase the probability of streamer flashover since they extend the effective HV conductor area [46]. Shields fitted to the tops (and bottoms) of vertical insulators have also been used and shown to be effective [4,7,23]. ...
... When determining the appropriate mitigation actions, practitioners may use perch deterrents, insulator shields, and/or alternative perch sites to reduce the risk of bird electrocution due to streamers. Other options include reconfiguration, retrofitting with insulation, and retrofitting using perch management [46]. The following points need to be taken into consideration. ...
... • Cross-arm dimensions (or its existence altogether) are essential [46], as they provide horizontal areas that are attractive to birds. • Experience has revealed that faults occur on the outer phases where the landing plates are not fully protected, which leaves roosting space for birds. ...
Bird streamer faults occur when the streamer, i.e., bird excretion, bridges the gap between two energized components or an energized and an earthed component of a tower structure. This results in a short circuit, which may be accompanied by an outage in the electricity supply. Due to the impact of these faults on electrical infrastructure and bird mortality, a detailed literature review to identify effective mitigation measures for sub-transmission lines (44–132 kV) and transmission lines (132–765 kV) was conducted. The findings show that there are several measures used internationally to reduce streamer-related faults, e.g., bird perch deterrents, shields, changing tower design configurations, changing insulator types and properties, and bird runways. Bird perch deterrents are typically most effectively used by many utilities; however, it is imperative that the perch deterrents are placed and installed correctly. Placement should be above potential problematic areas—to prevent the bridging of the gaps—at various points on different tower structures. Moreover, bird guards need to be monitored and maintained to ensure effectiveness over time. The involvement of a range of stakeholders when making environmental management decisions, such as researching and implementing the best mitigation measures, is also critical to ensure continued success.
... Mitigation measures include spikes to discourage perching in critical locations on towers and insulating covers above insulators to prevent streamer and contamination problems [11,12]. Spikes have been found to be effective in many cases [2,12], but care needs to be taken in their selection and placement. ...
... Mitigation measures include spikes to discourage perching in critical locations on towers and insulating covers above insulators to prevent streamer and contamination problems [11,12]. Spikes have been found to be effective in many cases [2,12], but care needs to be taken in their selection and placement. Spikes also have to be maintained as they have been observed to slide-about or are damaged by bird activity over time. ...
... IEEE Std 1651-2010 [9] recommends some mitigation techniques to reduce bird-related outages, mainly include reconfiguration of power lines with an avian-safe design, and retrofitting using insulated cover-ups or isolation by perch management. The other measures include changing tower configuration and insulator placement [10], and installations of some bird-preventing devices, such as shields and baffles, which This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. are designed according to the high-risk region of bird streamer flashover [11][12][13]. ...
Bird‐related outages greatly threaten the safety of overhead transmission and distribution lines, while electrocution and collisions of birds with power lines, especially endangered species, are significant environmental concerns. Automatic bird recognition can be helpful to mitigate this contradiction. This paper proposes a method for automatic classification of bird species related to power line faults combining deep convolution features with error‐correcting output codes support vector machine (ECOC‐SVM). An image dataset of about 20 high‐risk and 20 low‐risk bird species was constructed, and the feed‐forward denoising convolutional neural network was used for image preprocessing. The deep convolution features of bird images were extracted by DarkNet‐53, and taken as inputs of the ECOC‐SVM for model training and bird species classification. The gradient‐weighted class activation mapping was used for visual explanations of the model decision region. The experimental results indicate that the average accuracy of the proposed method can reach 94.39%, and its performance was better than other models using different feature extraction networks and classification algorithms.
... Research on bird droppings causing tripping faults in transmission lines is currently mainly focused on other voltage levels, such as 110 kV and 220 kV [14], [15], and primarily on the study of bird droppings flashover on Type I composite insulators of transmission lines [16], [17], [18]. However, there is relatively little research on bird dropping flashover on V-type composite insulators of 330 kV transmission lines, and existing bird deterrent measures have shown poor effectiveness after implementation [19], [20]. ...
Recently, the number of birds along the 330kV transmission lines in the northwest region has gradually increased. The frequency of birds nesting and excreting on the towers has been steadily rising, with bird droppings increasingly becoming the primary factor causing bird-related tripping faults. A three-dimensional model of tower crossarms, continuous bird droppings, and insulators was constructed to simulate and analyze the impact characteristics of bird droplet diameter, length, and relative position to insulators on the spatial electric field near the insulators. Experimental corrections were made, and based on simulation and experimental results, a bird-proof baffle was designed. Research results indicate that under conditions of single-ended grounding and suspended droplets of bird droppings, the average electric field strength at the lower end of the bird droppings and the grading ring was extracted to define the protective area against irregular-shaped bird droppings. After experimental validation, a correction coefficient of 1.4 was obtained based on the experimental results. A square protective baffle with a diversion function was designed based on simulation and experimental results. Bird droppings were placed at the baffle’s diversion groove, and the average electric field strength between the lower end of the bird droppings and the grading ring was consistently lower than the breakdown field strength of 2.98 kV/cm. The research results of this paper can serve as a basis for the subsequent designing of physical models of bird-proof baffles and prevention of bird-related flashover faults on V-type insulators.
... In Portugal, between 1984 and 2014, the proportion of white stork nests in electricity pylons increased from 1% to 25% of the whole national breeding population . These nests can create an increased risk of faults (Taklaja et al., 2014;Zhou et al., 2009). Thus, the Portuguese transmission system operator (TSO) initiated in the mid-1990s a nest management program that entailed the removal or translocation of hazardous nests to nesting platforms installed in safe locations of (the same) pylons and the setting of anti-perching devices to discourage storks from nesting and perching in hazardous locations of the pylons, namely in the cross arms (above the conductors and insulators) (Gomes-Mota et al., 2014). ...
Bird nests on transmission lines can cause electrical faults which reduce service reliability. To address this problem, since the mid-90s, the Portuguese Transmission System Operator (TSO) has undertaken management actions to discourage white storks Ciconia ciconia from nesting in hazardous locations of the pylons. Here, we compiled and analyzed an 18-year series of data on electrical faults, TSO management actions to tackle these, and stork nests on transmission pylons in Portugal to: (a) determine the relative importance of bird-related faults over the total number of faults; (b) describe variations in bird-related faults across time (season of the year and time of the day); (c) describe spatial variations in bird-related faults and their association with the occurrence of white stork nests on pylons; and (d) analyze the trends, over the years, of the number of white stork nests on pylons, the TSO management actions and their effectiveness in reducing bird-related fault rates. Overall, birds accounted, on average, for 25.3% of the electrical faults in the transmission network, with the vast majority being attributed to white storks. The seasonal pattern of bird-related faults showed higher rates in April and in October–November. Faults occurred more often during the night period, when storks spend more time on the pylons. We found a positive spatial relationship between the electrical fault rate and the proportion of pylons with stork nests (and the correlated number of nests per 100 km of line). There was, however, considerable variation in the fault rates not explained by the stork nest variables, particularly during the non-breeding season. The TSO management actions (namely removal/translocation of nests in hazardous locations of the pylons, installation of anti-perching devices and provision of alternative nesting platforms) significantly reduced, as a whole, the annual number of bird-related faults between 2001 and 2018, despite the three-fold increase in the number of white stork nests on transmission pylons. A deeper understanding of how white storks use the transmission pylons outside the breeding season is needed, so that targeted management actions can be taken to reduce the remaining bird-related fault rates to residual levels.
... As for the problem of bird damage, there are many researches on anti-bird devices such as needle, shield, and box of bird guard etc. Taklaja [4] reduced bird residence time by improving insulator structures to avoid flashover caused by bird excrement. Yang [5] discussed the protection radius of a bird-preventing installation by studying the mechanism of insulator flashover caused by bird streamer. ...
Abstract Efficient bird damage prevention of transmission lines is a long‐term challenge for power grid operation and maintenance. An approach combined lightweight convolutional neural network (CNN), image processing and object detection is presented in this paper to detect typical bird species related to transmission line faults. An image dataset of 20 bird species that threaten transmission line security is constructed. The YOLOv4‐tiny algorithm model is constructed and trained combining stage‐wise training, mosaic data enhancement, cosine annealing, and label smoothing. The mean average precision (mAP) can reach 92.04% on the test set by adjusting the parameters of the training process. Then, the validity of the proposed method is verified according to the test results and performance indexes by comparing with other methods, including Faster RCNN, SSD, YOLOv4 etc. Some image pre‐processing methods such as motion blur, defocus blur, contrast and brightness adjustment are used to simulate the scenarios in practical engineering applications. The proposed method can detect bird species perched around transmission lines with high‐efficiency, which is useful for differential prevention of bird‐related outages of power grids.
The increase in bird populations along the Hexi Corridor has led to an increase in flashover faults on 330 kV transmission lines caused by bird droppings. To mitigate the issue of line tripping caused by bird droppings, it is necessary to analyze the distribution of the electric field near composite insulators during the process of bird droppings falling. A three-dimensional model, including the tower, bird droppings, and insulators, was created to assess the impact of bird droppings’ characteristics on the electric field near the insulators. Based on simulation results, a bird-proof cover was designed to modify the trajectory of the bird droppings’ path. The research found that when bird droppings are grounded and continuous, the most severe distortion of the residual air gap field occurs at a distance of 599.34 mm from the insulator axis. In the dynamic process of ungrounded and continuous bird droppings falling downward with a length less than 3200 mm, the electric field intensity in the residual air gap remains below 5.66 kV/cm outside the circular area centered at the insulator skirt with a radius of 740 mm. Based on the simulation results under both single-end grounded and ungrounded conditions of bird droppings, a bird-proof cover structure was devised to alter the location where bird droppings fall. After bird droppings fall along the edges of the bird-proof cover, the average electric field intensity between the bird droppings and the high-voltage terminal is maintained below 3.02 kV/cm. These research findings lay the foundation for subsequent fabrication of physical models of bird-proof covers.
In order to obtain the bird streamer flashover characteristics in high altitude areas, the discharge of DC V-type string insulators was studied in high-altitude test base at 4 300m in Tibet. The study results show that medium viscosity bird streamer is easy to form a continuous channel and cause flashover. The flashover probability of positive polarity transmission lines is slightly higher than that of negative. The conductivity of bird excrement almost has no effect on the flashover probability in the range of 1.9∼20.9mS/cm. To increase the vertical air gap distance can reduce bird streamer flashover probability. Based on the experiment results, the recommended vertical air gap distance values of ± 400kV DC transmission line were proposed. Considering the influence of wind and bird streamer falling angle, the protection radius was set 3.5m at 3 500∼5 000m altitude area. Bird streamer flashover is a mixed discharge of air gap breakdown and the surface discharge along the bird streamer channel, at the altitude of 4 300m area, the minimum breakdown potential gradient is about 2.1kV/cm, and the discharge between bird streamer and shielding ring can be approximately equivalent to rod-rod gap discharge.
Bird-related flashover is a major factor of transmission line outages according to IEEE Guide for Reducing Bird-related Outages. In recent years, with the improvement of people's awareness of environmental protection, the probability of bird streamer flashover increases especially in 110 kV transmission in China. The high-risk region of bird streamer flashover is generally believed as a circular area centred on the suspension point of the insulator at present, and many bird-preventing installations such as shield and baffle are designed according to it. However, bird-related flashover still occurs protected by such installations, the current high-risk region of bird streamer flashover and the performance of these installations may not be clear needing further research. In this paper, a simplified platform of 110 kV transmission line tower was built to simulate the process of bird streamer flashover at different dropping positions on the cross arm. The result shows that the protection radius R changes with the dropping position of bird simulation excrement. Electrostatic simulation was carried out to study the distributions of electric field during the flashover process and the experiment results are verified. High-risk region of bird streamer flashover in 110 kV composite insulators is quantitatively obtained through emulation, and the shape is more like a “flying saucer”. A new bird-preventing shield with the function of “drainage” is designed accordingly, whose effect is verified and evaluated by comparison experiment.
According to IEEE Guide for Reducing Bird-Related Outages, several types of transmission line faults could be induced by birds. The number of birds increases as human awareness of environmental protection increases. Thus, the probability of suspension insulator string flashover induced by bird streamer would also increase. Analysis of transmission line faults in Yunnan, China, shows that many transmission line faults occurred in the winter bird migration zone, and most of the towers affected are 110 kV transmission line towers. Hence, investigating the flashover process of the 110 kV transmission line suspension insulator strings induced by bird streamer and designing a well bird-preventing installation for 110 kV transmission line suspension insulator strings is necessary. In this study, a simplified, self-designed 110 kV transmission line tower is utilized to experiment on the three types of 110 kV transmission line suspension insulator string with bird simulation excrement. The analysis of withstand test results has revealed the mechanism of flashover caused by bird streamer of the three types of suspension insulator string, and the protection radius R of the three types of insulator string has been presented. The mechanism of flashover and test results have been testified by means of the distributions of electric field and potential calculated by FEM method. Thus, the bird streamer caused flashover could be classified as the shortest air gap breakdown. Hence, it is valuable for designing or selecting a well bird-preventing installation.
This paper presents the AC-voltage withstand performance of field aged 110kV transmission line glass insulator strings investigated under different environmental conditions. Insulator strings were removed from two 110 kV lines, one located near a coastal area and steel mill industry and the other located inland next to a dump. AC-voltage withstand levels were tested and leakage currents across insulator strings were measured in dry, mist and wet conditions. Results suggest that the polluted insulators from the steel mill should be replaced whereas protective measures need to be applied to the insulators at the dump to mitigate bird-related problems.
Bird streamers have long been overlooked as an important faulting mechanism on transmission lines. After exhaustive analysis, bird streamers were identified as a major source of faulting on Eskom's transmission grid in South Africa. A national bird guard project was launched to eliminate the problem on selected lines. Preliminary results indicate that the project has succeeded in virtually eliminating bird streamers as a cause of faulting on the lines fitted with bird guards
Electric field calculations are not common practice in the design and development of non-ceramic insulators for high voltage transmission applications. This paper applies a three-dimensional (3D) electric field analysis program to calculate the field distribution at the live-end of 275kV and 330 kV non-ceramic insulators used in the Queensland transmission system. At these voltages, fields can be high enough to cause damage to the insulator sheath due to corona discharge, and grading devices need to be used to reduce the electric field to acceptable levels. Of particular interest to this research was the effect of end-fitting geometry and corona ring geometry on the electric field at the live-end of high voltage non-ceramic insulators. Three different non-ceramic insulator types were compared, and their fields are shown. Also a number of different ring geometries were compared. The effect of changing ring cross-sectional shape, diameter, and placement along the insulator are shown. All of these were found to influence the electric field at the live end.
Bird streamers have long been overlooked as an important faulting
mechanism on transmission lines. After exhaustive analysis, bird
streamers were identified as a major source of faulting on Eskom's
transmission grid in South Africa. A national bird guard project was
launched to eliminate the problem on selected lines. Preliminary results
indicate that the project has succeeded in virtually eliminating bird
streamers as a cause of faulting on the lines fitted with bird guards
Electrical faults on transmission lines are an important source of power disturbances. These faults have a variety of causes, including fires, lightning, insulator pollution, animal electrocutions, and equipment failure. Important faulting mechanisms that have hitherto been largely overlooked are bird streamers. In this article, the role of bird streamers as a faulting mechanism are discussed, as well as remedies to reduce the problem. Results obtained in South Africa through the application of remedies are presented.
Bird related outages are more common and widespread than generally believed. The objective of this paper is to review the existing bird related problems and to recommend practices and procedures that are successful in reducing bird related outages on transmission lines, in substations and on overhead distribution lines. Experience has shown that use of perch guards, metal or plastic spikes, insulating caps, alternate perch sites and washing have significantly reduced bird related streamer and contamination outages.
This paper applies a three-dimensional (3D) electric field analysis program to calculate the field distribution at the live end of 110 kV non-ceramic insulators used in the Queensland transmission system. A number of 110 kV insulator configurations have been modelled, including a post, a longrod and a horizontal vee assembly, to determine the electric field on the sheath at the live end. It has been observed that birds will only chew the dead end of insulators. Based on modelling and the proximity of bird chewing damage to the live end, the maximum electric field that birds will tolerate has been estimated. Of particular interest to this research was the effect of corona ring geometry on the electric field at the live end of high voltage non-ceramic insulators. At 110 kV, manufacturers do not recommend the fitting of corona rings to reduce the electric field. However, for 330 kV non-ceramic insulators, manufacturers recommend fitting corona rings at the live end to reduce the electric field so that sheath damage due to corona discharge is minimised. The 110 kV non-ceramic insulator electric field values from modelling are compared with those of 330 kV longrods from earlier work. This paper comments on whether corona rings should be applied to 110 kV non-ceramic insulators based on the maximum levels of corona on the sheath at the live end of longrods. A number of different corona ring geometries were compared. The effect of changing ring cross-sectional shape, diameter and placement along the insulator are investigated.
The study considers causes of indefinite faults in the 110 kV overhead power grid in Estonia. The number of indefinite faults (flashovers on overhead line insulators) has increased significantly in the last years, causing a lot of problems to the transmission system operator (TSO). The study claims wildlife, more specifically migrating birds white storks, to be responsible for most of the indefinite faults in the power grid (excremental contamination).
The study aims to elucidate which type of bird excrement contamination causes insulator flashovers in 110 kV overhead power lines in Estonia. Laboratory wetting and bird streamer tests performed on naturally contaminated glass and composite insulators show that most likely the flashovers are caused by highly conductive bird excrement streamers and that insulator properties have little influence, if any, on the generation of this kind of contamination driven flashovers.
The transmission lines trip accident caused by bird streamer has become increasingly prominent. It is more common and widespread than generally believed, and greatly threatens the reliability of transmission lines. In this paper, a kind of liquid to simulate bird streamer is been made according to the electric conductive and viscosity of bird excrement (bird streamer). The experiment platform is set up in the laboratory to study the AC discharge characteristics of tower-line air gaps under the influence of bird streamer. At the same time, discharge model caused by bird streamer is been established with the use of COMSOL Multiphysics to investigate its breakdown mechanism. The results show that, air gap breakdown voltage decrease by about 80% under the influence of bird streamer. And in view of this kind of accident, some methods to prevent from these faults are provided in this paper.
Bird-caused outages are more common and widespread than generally believed, and greatly threaten the safety of transmission lines. However, few reports are concerned with laboratory research of bird-caused faulting, especially in the case of long air gap insulators. This paper carried out experimental and simulation work on bird streamer flashover of 220kV insulators. It was found that the radial distance from the insulator axis shows great influence on the bird streamer flashover. Significant is that we also found a high-risk region of bird streamer flashover which can be restricted in an elliptical region located at the center of 220kV insulator string, the major and minor axes being 500mm and 250mm. The processes of flashover due to bird streamer are discussed in detail. Simulation work further demonstrates the existence of the elliptical region of high flashover risk, which is of significance for transmission line protection.
The bird-streamer caused failures have become one of the major causes of transmission line outages. It is more common and widespread than generally believed, and greatly threatens the reliability of transmission lines. The laboratory study of such failures mechanism is seldom reported especially for long gaps such as 500 kV insulators. Presented in this paper are the results of long air gaps bird streamer flashover experiments conducted on 500 kV and 220 kV transmission line insulators. The experimental results demonstrated that bird-streamer caused surface flashover can happen in 500 kV insulators, however space flashover, because the bird streamer will split into different jets under high electric field cannot short circuit the long air gaps. The high risk areas of flashover for 220 kV and 500 kV insulators were defined in this paper: an elliptical area for 220 kV I string insulator and a symmetrical area beside the central line for 500 kV V string insulator. The influence of some main factors on flashover processes is also elucidated, such as volume, conductivity and viscosity of the streamer, and the insulator type and configuration. The paper has significant value in understanding the bird caused failure mechanisms and designing remedies.
A study of the role played by bird streamers (bird excretements) in transmission line faults under HVDC conditions is described in this paper. The research was initiated due to the lack of knowledge regarding this phenomenon. An insight is given as to what bird streamers faults are, and their role in the breakdown of air-gaps. A model HVDC transmission line tower has been built at the HVDC laboratory at the University of KwaZulu-Natal. The tower was used facilitate in the air-gap breakdown tests. The tests were carried out in order to find the minimum distance required on a transmission tower top for a flashover to occur. The results obtained show that a streamer effectively reduces the air-gap between the tower and the live fitting on a tower. An indication of future work will be given.
Florida Power and Light Company (FPL) transmission lines with
excessive unknown cause outages were investigated and determined to have
experienced bird streamer flashovers. Findings are extended to similar
lines and the frequency of bird streamer occurrences are estimated.
Outage patterns associated with bird streamer flashovers are presented
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Wintering black storks (Ciconia nigra) cause severe damage to transmission lines in Israel?a study on the risk and mitigation possibilities
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Mitigation of transmission lines against Bird Hazards—the Israeli experience, " presented at the EDM Int
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Mitigation of transmission lines against Bird Hazards?the Israeli experience
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