Power Line Conditions Research Articles

Capacitive Sensor for Monitoring the Condition of Suspended High-Voltage Insulation

The purpose of the work is to develop the design of a sensor for monitoring the condition of high-voltage power lines suspended insulation. To achieve this goal, a diagnostic criterion was selected, the operating principle and design of the insulation monitoring sensor were determined. As a diagnostic criterion is considered a changing of voltage on the insulator plate due to a change in the distribution of electrical potential on the insulators, caused of damage in the insulators string. For the diagnostic system implementation was adopted a sensor based on a capacitive divider. The calculations confirm the pos-sibility of registration a damaged element in a insulators string by getting of voltage change at the sen-sors output. The calculation results were verified by modeling in the Multisim software. The parameters of the sensor were calculated, correctness of it is confirmed by the results of laboratory measurements of the new insulators plate capacitances, as well as insulators destroyed as a result of operation. The most important results of the research are the selection of the optimal diagnostic criterion and research-ing of the proposed design sensor effectiveness for assessing the suspended insulation condition. The significance of the results obtained lies in the fact that the developed design of a sensor allows one to obtain prompt information about the presence of damage in the insulation. The use of the proposed sensor design will make possible creation a continuous diagnostic system and identify damage at an early stage, which will ensure timely maintenance.

A UAV Intelligent System for Greek Power Lines Monitoring.

Power line inspection is one important task performed by electricity distribution network operators worldwide. It is part of the equipment maintenance for such companies and forms a crucial procedure since it can provide diagnostics and prognostics about the condition of the power line network. Furthermore, it helps with effective decision making in the case of fault detection. Nowadays, the inspection of power lines is performed either using human operators that scan the network on foot and search for obvious faults, or using unmanned aerial vehicles (UAVs) and/or helicopters equipped with camera sensors capable of recording videos of the power line network equipment, which are then inspected by human operators offline. In this study, we propose an autonomous, intelligent inspection system for power lines, which is equipped with camera sensors operating in the visual (Red-Green-Blue (RGB) imaging) and infrared (thermal imaging) spectrums, capable of providing real-time alerts about the condition of power lines. The very first step in power line monitoring is identifying and segmenting them from the background, which constitutes the principal goal of the presented study. The identification of power lines is accomplished through an innovative hybrid approach that combines RGB and thermal data-processing methods under a custom-made drone platform, providing an automated tool for in situ analyses not only in offline mode. In this direction, the human operator role is limited to the flight-planning and control operations of the UAV. The benefits of using such an intelligent UAV system are many, mostly related to the timely and accurate detection of possible faults, along with the side benefits of personnel safety and reduced operational costs.

Development of new methods for assessing the technical condition of power lines using digital image processing

An important role in satisfying the high quality of life of the population and modern industry is played by the reliability of power supply and ensuring uninterrupted delivery of electricity. As a result of a large number of emergency failures of elements caused by external factors, information about the technical state of elements in real time is not used by dispatching centers. These conditions cause difficulties in assessing the reliability of power lines and timely elimination of developing defects, which cause high transmission losses and lead to wire breaks and failures.Considering a digital photo or other raster image to assess the surface of power lines wires, we know that it is an array of numbers recorded by sensors of brightness levels, in a two-dimensional plane. Knowing that in mathematical terms a thin lens performs the Fourier transform of images placed in the focal planes, it is possible to create image processing algorithms, which are analogues of image processing by a classical optical system. An algorithm for automatic processing of scanning electron microscopy images aimed at detecting and describing surface defects in power line wires is proposed, which is implemented in the Python programming language. The algorithm proposes to use a Fourier transform procedure to eliminate the image brightness gradient and suppress high-frequency noise in the image by applying a two-dimensional bandpass filter. The necessity and parameters of the dynamic range normalization of the filtered image are determined. The binarization parameters of the normalized image are determined. A quantitative assessment of the degree of defectiveness of the investigated wire surface has been proposed. A quantitative assessment of the degree of elongation of defects on the surface of the investigated wire has been proposed.

Methodology Approbation for the Overhead Power Lines Sag Determining by the Period of Conductor Owned Oscillations

The relevance of the problem is justified and the review of existing methods for determining the overhead line sag by the period of the conductor owned oscillations is conducted. The method of controlling the sag by the period of its own oscillations is briefly presented. The experimental installation for conducting full-scale tests is described, which includes the conductor (64 m), rigid fasteners at the points of conductor suspension, accelerometer, and temperature sensor mounted on the conductor, data from which are processed and recorded by the specialized software. The measurement method is explained with a detailed description. The conductor oscillations spectral analysis is performed. The results of experimental main harmonic frequency measurements, conductor, and changes in the sag are presented. A comparative results analysis showed the efficiency of the proposed method. The described method for determining the sag is easy to use (it is enough to install an accelerometer on the conductor and process data from it) and can be recommended for monitoring the condition of overhead power lines. The correlation of changes in the conductor oscillations spectral harmonics amplitude with temperature was studied. It is found that the correlation coefficient initially increases with the growth of the harmonics number. It is maximal for the ninth harmonic R = −0.9, and then slowly weakens, remaining between 0.9 and 0.8. This property of high-frequency harmonic oscillations can be used in the high-voltage lines condition diagnosis.

PROPOSALS FOR THE ESTABLISHMENT OF A REMOTE DIAGNOSTIC DEVICE FOR CONTROL OF THE TECHNICAL CONDITION OF OVERHEAD TRANSMISSION LINES 6-35 kV

Today, the main activity of Ukrainian electricity companies is to meet the ever-growing needs of Ukrainian consumers in quality and reliable electricity supply. For this purpose, constant work is carried out on the reconstruction of electrical networks and construction of new energy facilities on the basis of a new regulatory framework adapted to world standards. The article proposes to determine the location of damage to a branched power line with several power sources, namely, to create a device for diagnosing power lines. The device for diagnosing power lines is designed to isolate the damaged branch in the branched overhead power lines, and measure the distance to the place of damage. The operation of the device is that the meters of inhomogeneity of cables and lines measure the delay time of the probing pulses reflected from the place of damage of the branched power lines, from the beginning of the main line and from its end. Next, the total delay time of the probing pulses reflected from the place of damage of the branched transmission line is compared with the time of passage of the probing pulses on the main transmission line, if the delay time is equal, the damage is on the main transmission line. branch. Then, based on the obtained measurements, the exact location of the damage on the power line is calculated. The technical result is to increase the accuracy of determining the location of damage on branched transmission lines with multilateral power supply by attracting a priori information (known all the inhomogeneities of a good transmission line) and the location of the transmission line inhomogeneity (branching) and measuring . The proposed approach does not involve the use of specific instruments for measuring current and voltage values, but is based only on measuring the delay time of probing pulses using line inhomogeneity meters. Determining the importance of constant diagnostics of the technical condition of power lines in the article shows one of the real ways to create a remote diagnostic device that can be implemented on modern elements and computer technology.

Characteristics and parameters of the technical condition of overhead power lines

Characteristics and parameters of the technical condition of overhead power lines

DEVELOPMENT, DESIGN AND APPLICATION OF UNMANNED AERIAL VEHICLES FOR POWER LINES

The article reviews the methods for improving the technology of monitoring and inspection of the state of power grids. The state of development in the design and methods of using unmanned aerial vehicles, which are intended for servicing power lines, is analyzed. A number of issues related to the concept of unmanned aerial vehicles with high lifting capacity are considered, which allows them to be used for various means of maintenance of power lines, which in turn reduces capital costs. Unmanned aerial vehicles are increasingly being used by utilities, which reduces the risks and costs of maintenance compared to other transmission line monitoring systems. It was determined that in the field of electric power industry the most promising of the methods for monitoring power lines is the application of unmanned aerial vehicles together with the use of modern measuring equipment and digital technologies. It is concluded that a significant advantage of the use of unmanned aerial vehicles is their possibility, which reduces costs and increases the efficiency of their use as a means of determining promising locations for wind farms. It is noted that with the transition of the global electricity industry to the use of unmanned aerial vehicles will save resources and reduce costs. Moreover, it is determined that the use of unmanned aerial vehicles with high lifting capacity allows minimizing the cost of using additional lifting equipment and technical personnel. In particular, high-lift unmanned aerial vehicles using flamethrowers can effectively remove obstacles such as clogging on power lines. It is noted that the use of unmanned aerial vehicles will increase the safety of employees in the maintenance of power facilities and power lines. The obtained results from the analysis of the technical condition of the use of unmanned aerial vehicles indicate the prospects for the introduction of remote control systems and monitoring of the operational condition of power lines.

Short-Term Electromagnetic Interference on a Buried Gas Pipeline Caused by Critical Fault Events of a Wind Park: A Realistic Case Study

Short-term electromagnetic interference (EMI) pertains to the total result produced by the occurrence of intermittent, inductive, and conductive couplings on a buried pipeline system. For example, this type of EMI takes place when considering the fault conditions of a single ac power line, acting in the nearby vicinity of a pipeline system. In the context of this article, the effect of the short-term EMI is unfolded through a real case study. This case study involves a 20.7-MW wind park (WP) with extended underground power cable connections, which are laid nearby a high-pressure gas pipeline system. In particular, the impact of critical fault events, associated with the WP's power cables, on the pipeline system is comprehensively assessed. The assessment is achieved by the concurrent use of two powerful software tools that are respectively eligible for the accurate short-circuit analysis of the electrical circuit of the WP and for EMI evaluation on the pipeline. To this extent, the simulation results are thoroughly discussed and an effective mitigation solution is evidently presented.

Experimental system for continuous monitoring of overhead power lines and substations insulation

This paper describes a system for monitoring the insulation condition of overhead power lines and substations based on sensors installed on towers and insulators. The sensors works on the capacitive coupling with an insulating structure and register the appearance and growing of electrical discharges near the insulators. The data from the sensors with a predetermined frequency (from 1 minute or more) are transmitted throw cellular communication to the operating service computer (smartphone) and presents as changing graphs on the screen. In this paper in operation and functional diagram of the system are proposed with described results of tests and experiments with manufactured product samples in laboratory and field conditions on an operating 110 kV line. The results of field experiments shows the advantages of the system to monitor the insulation in comparing with traditional diagnostic devices.

Detection of power line insulators on digital images with the use of laser spots

The massive growth of technologies used to register and process digital images allow for their application in evaluating the technical condition of power lines. However, it is not possible without a set of dedicated methods for obtaining diagnostic information based on registered video data. The method described here details the detection of power line insulators in digital images featuring diversified backgrounds using laser spots. The algorithm of detecting an insulator in analysed images is based on testing the digital signal of pixel intensity profiles read between subsequent pairs of laser points in the image. The method is comprised of the following stages: import the image with laser spots, detection of spots on the image, and pattern classification of each image profile that is calculated for each found laser spots pair. The evaluated profiles depicting an insulator were characterised by regular patterns that reflect the target structure. To classify profiles as either insulator containing or non-containing, several steps should be followed: averaging the signal, removing the linear trend, finding and alternating the minima and maxima. The performance of the proposed method was verified using an open-access dataset, comprised of various scenes featuring high-voltage power line insulators.

Determining of the Real Condition of High-Voltage Overhead Power Lines

Determining of the Real Condition of High-Voltage Overhead Power Lines

Atmospheric Sensors and Energy Harvesters on Overhead Power Lines.

We demonstrate the feasibility of using novel, small energy harvesters to power atmospheric sensors and radios simply attached to a single conductor of existing overhead power distribution lines. We demonstrate the ability to harvest the required power for operating multiple atmospheric and power-system sensors, together with short-range radios that could broadcast atmospheric sensor data to the cellphones of people nearby. Occasional long-range broadcasts of the data could also be made of both atmospheric and power-line conditions.

Разработка роботизированного летательного комплекса для мониторинга состояния линий электропередач

The prospects of putting in use a mobile robotic drone-aided system for monitoring the condition of power lines are considered. Monitoring and inspection of power lines are among the mandatory measures carried out by electric network companies in order to maintain uninterrupted operation of the power grid. During power grid operation, emergency tripping of high-voltage overhead power lines account for 25% of all disconnections in the power system. According to the existing practices, power lines are inspected by patrol linemen, who walk along the power line route for visually checking its condition. Inspections involving climbing/ascending over the power line supports are also carried out, which, however, are not always absolutely free from life-threatening risk. The condition of power lines passing in hard-to-reach-areas is inspected using a helicopter, which sometimes turns to be an economically unprofitable measure. It follows from the performed analysis that the main drawbacks of the existing facilities for monitoring the condition of power lines is that they provide insufficient information and that they are poorly adapted to operation under the conditions of a strong electromagnetic field. In addition, a helicopter is required to ascend these systems for monitoring a de-energized power line. The proposed project is aimed at achieving more reliable power line monitoring data and obtaining the possibility to perform remote visual inspection of the condition of power line wires. The proposed system is characterized by a number of new features. Thus, its design allows the system to be connected to the power line wires without the need to de-energize the line. In addition, the system and the input data processing algorithm reduce the information burden on the operator owing to the availability of video data analysis functions, which minimize the amount of background flow of video data. Unlike airplane-type unmanned flying vehicles, which need a specially prepared runway for takeoff and landing, the proposed system can lift off from any place, a feature that is of special importance for hard-to-reachplaces, e.g., in a mountainous terrain. The developed device can hover at the closest distance to wires and, if necessary, it can be put in contact with the power line wires. All these features make it possible to obtain a flow of high-quality information in different frequency spectra and foreshortenings of power line elements. Tests of the developed system have shown that the measurement data obtained from its mobile part feature high accuracy. In view of the fact that timely and reliable detection of flaws and unsatisfactory condition of power line wires and power line accessories is among the main problems faced by the modern electric power industry, the proposed system will find an extensive use in the industry.

Assessing the effects of underground mining activities on high-voltage overhead power lines

This paper introduces a technique for predictive assessment of changes in the position of power transmission towers and condition of overhead power lines, located in the zone of influence of displacements and deformations of the Earth's surface caused by mining activities. A special approach for monitoring the technical condition of towers and cables is proposed. It is intended to address the issue of controlling the condition of transmission lines that are under the influence of underground mining activities and to checkmate such impact.

Determination of geodetic control network points using GPS technology for the purpose of monitoring power lines in difficult terrain conditions

Summary The present work discusses the issue of determining geodetic control network in order to monitor the condition of power lines. The problem was presented using the example of the physical survey of an actual infrastructure – a high voltage power line. Difficult terrain conditions constituted a significant factor for determining an appropriate measurement method. The measurement itself was conducted using two methods, independently of one another: the classical traverse method, and the RTK (Real Time Kinematic) GPS method. The following criteria were assumed for the purpose of the comparison: measurement effectiveness and the accuracy of the calculation result. Basic monitoring procedures of power lines were also presented, implemented based on the measurement network established beforehand.

Performance of Space–Time–Frequency Coding Over Indoor Power Line Channels

We present a multiple-input-multiple-output (MIMO) power line communication (PLC) system using coupled indoor differential mode ports, where 2 × 2 and 2 × 4 MIMO configurations are considered. In simulation, MIMO orthogonal frequency-division multiplexing (OFDM) PLC with the two OFDM symbol sequence reordering schemes, namely, Alamouti-scheme-based sequence reordering and circularly-shifted sequence reordering, is compared under the coupled channel conditions. For MIMO coding, we employ a maximum ratio combining scheme that is effective for both MIMO and single-input-single-output over indoor power line conditions. In simulation, we compare space-frequency coding (SFC), space-time coding (STC), and space-time-frequency coding (STFC) over statistical indoor power line channels, including fading, impulse noise, and crosstalk by coupling between ports. STFC and STC are more robust against crosstalk than SFC, and STFC, with some added complexity, outperforms the other coding schemes in terms of bit-error-rate performance. A least squares scheme for power line channel estimation is used, which is simple but has comparable performance to minimum mean square error. A decision-feedback-loop-based crosstalk cancellation scheme that effectively reduces the MIMO channel estimation error due to crosstalk is presented. Simulation results show that STFC is less sensitive to impulse noise than STC or SFC.

Three–Parameter Feedback Control of Amorphous Ribbon Magnetization

This work describes a specially developed software for controllable magnetic hysteresis measurements of amorphous and nanocrystalline ribbons. The sophisticated algorithm enables to simplify a hardware design and to suppress an influence of experimental conditions on the measurement results. The main software feature is a three-stage feedback algorithm, which accurately adjusts the magnetization conditions: magnetization amplitude, geomagnetic bias and magnetization waveform. Air flux compensation of the induction signal is also performed by the software using an effective value of the coil cross section obtained from a calibration measurement without the ribbon. Applicability of the designed setup is illustrated for a series of nanocrystalline Hitperm ribbons measured at the power-line conditions: 50 Hz frequency and sinusoidal magnetization waveform.

연소화염 존재 시 수직형 모델 전력선의 섬락 특성

전력선이 통과하는 지역에서 발생된 산불은 계통 섬락사고의 원인이 되고 있다. 본 연구에서는 연소화염에 의한 전력선의 절연내력 저하특성을 알아보기 위해 직류 및 교류 전압 인가 시, 연소화염과 고전압 도체의 수평거리(s)를 변화시켰을 때, 수직형 모델 전력선에 대한 섬락특성을 조사하였다. 실험 결과, 수평거리(s)가 작은 범위에서는 화염이 모델선로의 섬락전압을 크게 감소시킬 수 있는 것으로 나타났다. 이러한 섬락전압의 저하요인을 해석하기 위해 화염주변의 상대공기밀도가 고려되었으며, 화염이 존재하는 경우에는 그 영향이 매우 크게 나타남을 알 수 있었다.

Power line monitoring system using fiber optic power supply

We propose a novel power-line-monitoring system using optical fibers for transmitting power as well as signal. The principle is experimentally confirmed with a system composed of a monitoring side with a 1.5-μm laser diode, transmission line of a single mode fiber, and a sensing side having an efficient photovoltaic (PV) cell, electrical junction sensor, and low power liquid crystal optical modulator (LCOM). The PV cell generates the electrical power in the sensing side with a conversion efficiency of 20%. The LCOM is driven with low power of less than 50 μW, modulates the laser light with a signal indicating the power line condition, and transmits the optical signal. The developed sensing unit produces an optical signal having an extinction ratio of 15 dB with low optical power of 1.8 mW. Five systems were in operation for two years, faithfully monitoring the oil pressure in electrical cables every 20 min without incident.

수직배열 모델 전력선의 절연파괴 특성에 미치는 화염의 영향

많은 나라에서 가공 송전선로 아래에서 발생된 산불에 의해 계통 섬락사고를 일으키고 있다. 본 연구에서는 상용주파수 교류 및 직류 고전압을 인가하였을 때, 연소화염에 의해 전력선의 절연강도가 저하하는 특성을 조사하기 위해 수직배열 전력선에 대한 모의조건에서 다양한 실험을 수행하였다. 실험 결과, 화염이 없는 경우에 비해 연소 화염이 존재하면 화염의 거리(h)에 따라 절연파괴전압은 크게 저하되는 것으로 나타났다. 도체와 화염의 거리(h)가 작을수록 절연파괴전압이 감소하였으며, 교류전압 인가 시, h＝9[㎝]일 때 평균 46.2[%], h＝3[㎝]일 때 평균 62.5[%] 저하된 것으로 나타났다.