Lightning Protection Devices Research Articles

Mathematical description of leader channel propagation for selection of model experiment parameters and lightning guard systems

A statistical model of the leader channel propagating toward the Earth with consideration for its orientation relative to grounded objects is proposed, and the results obtained are compared with the predictions of model experiments. Recommendations of how to optimize model experiment conditions for gaining insight into the electric mechanism of the leader channel orientation relative to ground objects are given. The probability of hitting an area protected by a lightning conductor is calculated, and possible ways of improving lightning protection devices are outlined.

Movement simulation of long electric arc along the surface of insulator string in free air

This paper presents the study of a long electric arc in free air due to lightning stroke on the parallel gap lightning protection device (PGLPD) on high-voltage overhead transmission lines. Based on the latest electric arc model, the analysis method of the magnetic field generated by the current flowing through the PGLPD, electric arc, transmission lines, steel tower, and ground wires is developed, and the movement process of the long arc along the surface of the insulator strings is simulated. The simulation results are in agreement with the experimental results. The study is very helpful for the optimal design and suitable assemblage of the PGLPD.

Evaluation of Level Crossing Lightning Protection Measures

Building up effective and economical countermeasures is needed to prevent lightning damage to railway signalling systems. Therefore, we measured the wayside ground potential distribution when a rail potential rise was caused by injecting a lightning surge current into a rail. Moreover, we injected a lightning surge current into the rail or wayside ground, raising their potential in order to measure the lightning overvoltages on a level crossing so that basic insulation design data could be obtained. This paper demonstrates that an effective countermeasure is to earth lightning protective devices, which are attached to the electronic train detectors on a level crossing to suppress any lightning overvoltages.

MULTI-STATE RELIABILITY MODELS FOR LIGHTNING HAZARD ASSESSMENT

Lightning protection of buildings has been practised for ages but we still lack the model in terms of reliability theory. The paper is a proposition to apply some reliability models in the lightning protection. The building equipped with lightning protection is treated as the 4-state object. The intensities of transition from one state to another have been found on the basis of partial probabilities of inadmissible damages caused by a lightning stroke. The values of these intensities can be calculated on the basis of so called "partial risks" which are determined by entirety of the circumstances referring to the structure (the design, construction, content of the building, lightning protection device design, relief, geographical situation etc.).

Effect of Lightning Protective Devices Attached to Pole Transformers on Reduction of Overvoltage on Distribution Lines

Abstract: Class-10A solid-core insulators (BIL 90kV) have been used instead of class-6A pin insulators (BIL 60kV) in order to improve the insulation level of distribution lines. However, lightning protective devices attached to pole transformers may have the effect of reducing the overvoltages on phase conductors. We have investigated the lightning protection effect of devices attached to pole transformers by experiment and analysis using the EMTP (Electro-Magnetic Transients Program). The sparkover rate changes from 2.0˜3.3% to 5.5˜9.9% and increases 2.4˜2.8 times when the line insulator of the phase conductors is changed from class-10A to class-6A. It is thought that the insulation level of the line insulator can be reduced depending upon the local particularities, such as number of installed transformers, frequency of direct lightning stroke to the distribution line, and so on although the overall fault rate may increase to some extent.

Physical Properties of Radiation Fields Produced by Multiple In-cloud Lightning Discharges

This paper describes some physical properties and statistical analyses of radiation fields associated with multiple in-cloud lightning discharges. A wide-band waveform recording system was employed to analyze the time-domain characteristics of the radiation fields. The radiation fields produced by in-cloud lightning discharges were significantly different from cloud-to-ground return stroke fields and showed pronounced bipolar pulse peak amplitudes comparable to those of cloud-to-ground return stroke fields. The time intervals between the subsequent strokes for both the positive and negative radiation fields decrease as the stroke order increases. The ratio of the peak of the subsequent strokes to the first stroke peak is distributed over a wide range. Little difference was observed compared with the results for both the positive and negative polarities. The time intervals between the superimposing narrow stepwise pulses in the initial half-cycle of the pronounced bipolar pulse were in the range of less than 12 µs and the mean values for the positive and negative polarities were 4.43 µs and 4.78 µs, respectively. The statistics on the parameters of the electric and magnetic field waveforms seem to provide a good quantitative estimate of the lightning protection device response to the electromagnetic pulse effects of in-cloud lightning discharges.

Effective lightning protection schemes for distribution line

AbstractThe causes of lightning outage are subdivided into direct lightning strokes and induced lightning strokes, which are identified by the characteristics of the lightning overvoltage. In the past, lightning protection devices were directed mainly toward the latter, and attention has been focused on the installation of lightning protection devices, ground wires, and reinforcement of insulators. However, lightning outages continue to occur. Thus it is extremely important to clarify the fault characteristics of lightning surges and to study the effectiveness of various lightning protection devices by considering both direct lightning stroke and induced lightning stroke in order to prevent lightning outage in the future.In this research, the electromagnetic transients program (EMTP) has been applied to the direct lightning stroke, and the induced lightning outage analysis program for multiple conductor systems has been applied to the induced lightning stroke to study the effectiveness of lightning protection devices provided by combination of various lightning protection devices. The most effective lightning protection schemes are analyzed and evaluated based on verification tests on the full scale models as well as economic considerations.

Lightning Protection for an Oilfield Automation And Instrumentation System

A description of lightning protection devices in a computer-monitored oilfield automation project located on the south high plains of West Texas near Levelland. Lightning damage was substantially reduced with the present protection system. Introduction For many years, the problem of protecting electrical systems from lightning discharges has plagued power and communications engineers. Only within the past few decades has lightning been a problem to engineers dealing with electrical power systems in oil fields. The problem of lightning protection in West Texas oil fields is unique because of the high concentration of elevated high-voltage lines above flat plains that attract lightning discharges. Most modern, electrically operated oil fields have power distribution systems that are well protected from power distribution systems that are well protected from lightning discharges; and, in many cases, these systems are isolated by sectionalizers and other devices. Even if a portion of a field is disabled by lightning damage, the remainder of the field continues to function normally. This paper concentrates on protecting the low-voltage electronic instrument systems that are very susceptible to even minor voltage surges caused by lightning. In the last several years, the tremendous expansion of oilfield automation and electronic surveillance equipment has required increased emphasis on protecting low-voltage instrument systems from lightning discharges. These systems use DC voltages of near zero to 50 v with 120-v AC-powersources. This paper deals with methods used in a major oilfield automation project to protect various parts of the system from lightning damage. The lightning protection devices discussed are used to protect two of Amoco Production Co.'s computer-monitored oilfield automation projects located on the south high plains of West Texas near Levelland, Tex, plains of West Texas near Levelland, Tex, Fig. 1 shows schematically the automation project operating in one of the locations. This is a secondary waterflood unit with almost 700 wells. The unit is under the surveillance of a computer-monitored oilfield production automation system that utilizes about 1,500 status, production automation system that utilizes about 1,500 status, control, and measurement devices. It has about 150 miles of buried multiconductor cables ranging from 6- t50-pair cables. In this project, "pump-off" controllers are used to control the producing wells, have dry contacts, and indicate satisfactory controller operation and motor status. Water injection wells are controlled by mechanical pressure-regulating valves. The injection rates and pressures are monitored by the computer "reading" amplified signals from turbine meters and pressure transducers. pressure transducers. At satellite tank batteries, the status of tank levels, fire indicators, temperature, and other conditions is monitored with each end device having a set of dry contacts. Producing well tests are obtained by automatically Producing well tests are obtained by automatically switching individual flowlines to fired heater-treaters or separators using electrically operated ball valves. Dry contact meter pulses from these vessels are accumulated by the computer system to determine producing volumes and rates. The telemetry system consists of master and remote telemetry units. Communication between telemetry units is accomplished by frequency modulation using buried copper conductors. JPT P. 1405

Report on Industry Survey of Protective Gap Applications in High-Voltage Systems

The Working Group on Characteristics of Protective Gaps of the Lightning Protective Devices Subcommittee, IEEE Protective Devices Committee, carried out an industry survey on the use of spark gaps as surge protective devices in high-voltage systems. Of 91 utilities in the United States and Canada, 22 reported the installation of gaps in their systems, and 25, although not employing gaps at the present time, indicated their interest in gap applications. From the companies using gaps, information was received concerning gap construction, application, and service performance. Considerable variation in application practices is evident, depending upon individual system requirements and different approaches to the problem of station surge protection. The Working Group concludes that a recommendation or application guide for protective gaps would be of value to the industry.

“Deep freeze” metallurgy

This paper discussed briefly the basic connection between lightning phenomena and atmospheric electricity. Characteristics pertaining to lightning discharges were reviewed in order to elucidate some elementary mystics that are still associated with lightning events in some parts of the world and that lightning strike when and where it will. Various lightning protection principles were discussed. The essence of lightning protection device is to prevent lightning strikes from taking place over or around an installation or structure.

Performance Characteristics of Lightning Protective Devices [includes discussion

Performance Characteristics of Lightning Protective Devices [includes discussion

New lightning arrester standard

FOR THE PAST several years there have been three separate AIEE Standards bearing on the lightning Protective devices field: Report on Proposed Standard for Protector Tubes, AIEE 24, July 1940; American Standards for Lightning Arresters for A-C Power Circuits, AIEE 28, May 1944; and Proposed Standard for Expulsion Type Distribution Lightning Arresters, AIEE 47, December 1945; all prepared under the sponsorship of the AIEE Protective Devices Committee. By the time of the publication of AIEE Standard 47, it was evident that there was much material in these various Standards which had a common application, and many of the definitions and test procedures were common. W. J. Rudge, then Chairman of the Lightning Protective Devices Subcommittee of the Protective Devices Committee, perceived the advantages of merging all three Standards, and set up a working group for such a project. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> It was believed that the combining of Standards on lightning protective devices not only should lead to improved nomenclature, but would bring into sharper focus the inherent characteristics of the different species of lightning arresters, and at the same time would improve the accessibility of desirable information.

New Lightning Arrester Standard

FOR THE PAST several years there have been three separate AIEE Standards bearing on the lightning Protective devices field: Report on Proposed Standard for Protector Tubes, AIEE 24, July 1940; American Standards for Lightning Arresters for A-C Power Circuits, AIEE 28, May 1944; and Proposed Standard for Expulsion Type Distribution Lightning Arresters, AIEE 47, December 1945; all prepared under the sponsorship of the AIEE Protective Devices Committee. By the time of the publication of AIEE Standard 47, it was evident that there was much material in these various Standards which had a common application, and many of the definitions and test procedures were common. W. J. Rudge, then Chairman of the Lightning Protective Devices Subcommittee of the Protective Devices Committee, perceived the advantages of merging all three Standards, and set up a working group for such a project.∗ It was believed that the combining of Standards on lightning protective devices not only should lead to improved nomenclature, but would bring into sharper focus the inherent characteristics of the different species of lightning arresters, and at the same time would improve the accessibility of desirable information.

Performance Characteristics of Lightning Protective Devices

Performance Characteristics of Lightning Protective Devices

Report on Application of Lightning Protective Devices in Wartime

Report on Application of Lightning Protective Devices in Wartime

Application of Lightning Protective Devices in Wartime

UNDER present wartime conditions the need for conserving critical materials has been impressed upon the electrical industry with emphasis. It is for this reason that the lightning arrester subcommittee of the protective devices committee undertook a review of lightning protective devices and practices and their application to uncover and present any worth-while savings which it seems possible, practical, and reasonable to obtain. Within the short time since this project became active, it has not been possible to obtain committee agreement on all the various considerations involved. Therefore, rather than withhold from the industry the value of constructive study and suggestions already available, this paper is being presented without the sponsorship or any commitment by the lightning arrester subcommittee. It is hoped that its presentation and the discussions it will initiate will be helpful to the committee in continuing its work on this project to a conclusion. It is the purpose of the paper to give some results of a study on this problem up to the time the paper was prepared.

Proposed Standards for Outdoor Bushings

The AIEE joint committee on bushings has attempted to determine the electrical characteristics of bushings on an engineering basis. The recommendations in this report are based on the theory that an ample margin of insulation strength should be provided above the voltages to which the bushings may be subjected in service, including dynamic overvoltages, switching surges, and lightning surges up to the level of protection which can be provided with modern lightning protective devices. This should make it possible to use bushings having the same electrical characteristics for transformers, circuit breakers, and all types of apparatus of corresponding voltage ratings because, if bushings have an ample margin of insulation strength above the level of protection which can be provided, there should be no need for any higher insulation strength for bushings in circuit breakers than in transformers or other apparatus. Lower values of insulation strength may be assigned for bushings for small circuit breakers, distribution transformers, etc., where space or other limitations may require smaller bushings and where a smaller margin of protection may be satisfactory. The joint committee is continuing the study of bushings and will make additional recommendations covering indoor bushings as soon as agreement can be reached. They may also make recommendations covering bushings for lower-voltage ratings and possibly other characteristics of outdoor bushings.

The Shunt-Excited Antenna

The paper describes an arrangement for exciting a vertical broadcast antenna with the base grounded. Construction economy results through the elimination of the base insulator, the tower lighting chokes, and the usual lightning protective devices. The coupling apparatus at the antenna end of the transmission line is reduced to an extent which may make unnecessary a separate building for its protection. Greater freedom from interruptions resulting from static discharges is expected. The performance of the design is substantially the same as that obtained from the antennas now in general use. The paper describes experimental work done, results obtained, and inferences to be drawn from them. A mathematical appendix is attached.

Lightning Protection and Protective Devices for Power- and Substations

Lightning Protection and Protective Devices for Power- and Substations

Comparative tests of lightning protection devices on the Taylors Falls transmission system

Recent Institute discussions have brought out a decided difference of opinion on the value of certain lightning protective devices and have expressed a demand for positive data on line protection especially. This paper furnishes data obtained last summer on an operating line experimentally equipped with various protective devices. The results are of especial interest in being actual records made by means of tell-tale papers applied not only to the station protective devices but also to those on the line, and even to the line insulators themselves throughout the system.