Early Streamer Emission Research Articles

IMPACT AND MITIGATION OF LIGHTNING ON STRUCTURES AND INFRASTRUCTURE

Lightning poses a dual threat to buildings through direct and indirect strikes. Damage resulting from a direct strike includes the shattering of wood, windows, masonry, and other poorly conductive materials, as well as the burnout of electrical power and distribution equipment. Energy distribution transformers may also burst due to the impact of a direct lightning strike. On the other hand, indirect strikes can affect telecommunications lines, electricity cables, instrument data cables, and even underground plumbing, potentially carrying damaging lightning surges into a building. Certain fiber-optic cables may prove inadequate in providing sufficient protection. To safeguard structures from potential harm, two prominent technologies are employed: the Stormaster Early Streamer Emission Terminal and the Benjamin Franklin Rod. The former is the more commonly adopted approach, leveraging contemporary protective system technologies. Extensive research conducted during our project indicates that damage to a structure caused by an Early Streamer Emission terminal is less severe than that which would result from traditional lightning protection methods. An innovative advancement in this realm is the Non-Electronic Lightning Terminal, considered a more promising approach than its electronic counterpart. Further research on non-electronic lightning terminals, both in conceptualization and practical application, holds the potential to provide clearer insights into their efficacy and benefits.

A Study on Electric Potential and Electric Field Distribution for Optimal Design of Lightning Rod Using Finite Element Method

In this paper, we present an electric field analysis for the optimal structural design of lightning rods for high performance with a charge transfer system (CTS). In the case of a conventional rod that is produced with an empirical design and structure without quantitative data because the design is structurally very simple, only the materials and radius of curvature of the lightning rod to concentrate the electric field at the tip part of the rod are considered. Recently, the development of new types of lightning rods, such as early streamer emission (ESE) and charge transfer system (CTS), has been introduced through simulation analysis and experiments, but detailed specifications and information about the optimal design and structure have not been fully reported. In this paper, we performed an electric field analysis of the structures and materials for the optimal structural design of lightning rods with a function of CTS through computer software analysis with consideration for the radius of curvature, the size of corona ring, and optimal position (X-axis and Y-axis) of the floating electrode. For optimal structural design of lightning rods based on electric field analysis, we used a source of lightning voltage with 1.2/50 µs based on a double exponential equation. The results revealed that the electric field on the relaxation part decreases as the radius of curvature and corona ring increases. For the radius of curvature, the electric field first decreases and then increases with increasing radius of curvature and reaches a minimum at 7 mm and a maximum above 8 mm. For the case of the corona ring, the electric field decreases with increasing corona ring, and the optimal size of the corona ring was selected as 4 mm; the size of the 4 mm corona ring uniformly formed the electric field both at the tip part of the ground current collector and the corona ring. For the electric field concentration part, we found that the optimal X-axis position of the floating electrode and the Y-axis position between the ionizer conductor and floating electrode are 7 mm and 0.1 mm, respectively. These simulation results in this paper are expected to provide useful information for the design of optimized CTS-type lightning rods.

Experimental performance analysis of conventional and non-conventional lightning protection systems – preliminary results

There are still several uncertainties and conflicts regarding the lightning protection performances of conventional and nonconventional lightning protection systems. Discharge physics and experimental studies reveal the lightning protection systems' performances. However, there are also some studies suffering from commercial concerns. Theoretical efforts and test results are generally valid for specific configurations and are insufficient in generalizations. Another shortcoming of the experimental studies is that the experiments and experimental parameters are limited due to the limited laboratory facilities. This paper presents compact and comparative test results for Franklin Rods (FRs), charge transfer systems (CTSs), and early streamer emission (ESE) rods. For this purpose, the flashover voltage tests and lightning attachment rates of the mentioned protection systems are determined using switching impulses under the same electro-geometric conditions. Experimental results showed that FR and ESE terminals had similar flashover voltage and lightning attachment characteristics. CTSs could have performed better in diverting the lightning strikes when used alone. Therefore, there is a need for additional tests and field data to validate the claimed better lightning prevention performance of CTS systems and the lightning attachment performance of ESE terminals.

Five-Year Performance of an ESE Lightning Protection System for a Large Scale PV Power Plant in Thailand

This article presents a five-year performance review of an early streamer emission (ESE) air terminal lightning protection system for a large scale PV power plant in Thailand. The comparison effect of a Franklin lightning protection system and the ESE lightning protection system was analyzed for the PV power plant. The ESE lightning protection system was selected to be implemented in the PV power plant. The capacity of the PV power plant studied was 8 MWp on an area of 150,000 square meters in the Nong Ya Plong district, Phetchaburi province, Western Thailand. A Franklin lightning rod type was also designed to be implemented in this PV power plant. The Franklin lightning rod type comprised 122 pieces but the ESE lightning rod type consisted of only 11 pieces. The conceptual design of the Franklin rod type followed the standard of the Council of Engineers, Thailand, and the ESE lightning rod type followed the NFC17102 standard of France. The estimated cost of installation was a key comparison to select the lightning protection system; the total installation cost of the Franklin lightning rod type was USD 197,363.80 and the ESE lightning rod type was USD 44,338.06. The lightning system was applied to the lightning arrester in the power plant to provide good protection, in which the balance of the pole to the mounting position is required to optimize the system performance. The result of the simulation also showed that the shading effects of the Franklin rod type were greater than the ESE rod type. The installation cost of the Franklin lightning rod type was 4.45 times more expensive than the ESE lightning rod type. Therefore, the ESE lightning protection system was selected to be implemented in the PV power plant. From the recorded data of the five-year performance of the ESE lightning protection system (2016–2020), there were three occurrences of a lightning strike on the PV power plant. The ESE lightning protection system effectively protected and prevented the lightning strike to the PV power plant. This study can help and support with the selection of a lightning system for the protection of large scale PV power plants in the future.

Early Streamer Emission Vs Conventional Lightning Protection Systems

Abstract This paper analyses and compares the conventional lightning protection systems proposed in IEC 62305 to the lightning protection systems based on the application of early streamer emission lightning rods proposed in NF C 17-102. Comparison between the two approaches to the lightning protection of structures was presented, both from a technical and economic point of view. Some inconsistencies in the conventional air termination system design methods are pointed out. The critical attitude of the scientific community regarding the declared protection characteristics of the early streamer emission lightning rods is discussed.

Discharge characteristics of different lightning air terminals under composite voltages

Different types of lightning air terminals have been designed over the years. Concern regarding the effect of different types of air terminals, especially the early streamer emission (ESE)-type, remains controversial. This paper describes the discharge characteristics of different types of air terminals, two of which are quite similar to the ESE-type dynasphere, and concludes that the tested non-standard air terminals have discharge characteristics similar to those of Franklin rods and that their lightning protection performance should be similar.

The Similarity of the Action of Franklin and ESE Lightning Rods under Natural Conditions

In the lightning rods categorized as Early Streamer Emission (ESE) types, an intermittent voltage impulse is applied to the lightning rod to modulate the electric field at its tip in an attempt to speed up the initiation of a connecting leader from the lightning rod when it is under the influence of a stepped leader moving down from the cloud. In this paper, it is shown that, due to the stepping nature of the stepped leader, there is a natural modulation of the electric field at the tip of any lightning rod exposed to the lightning stepped leaders and this modulation is much more intense than any artificial modulation that is possible under practical conditions. Based on the results, it is concluded that artificial modulation of the electric field at the tip of lightning rods by applying voltage pulses is an unnecessary endeavor because the nature itself has endowed the tip of the lightning rod with a modulating electric field. Therefore, as far as the effectiveness of artificial modulation of the tip electric field is concerned, there could be no difference in the lightning attachment efficiency between ESE and Franklin lightning rods.

ASSESSMENT TO EFFECTIVENESS OF THE NEW EARLY STREAMER EMISSION LIGHTNING PROTECTION SYSTEM

Abstract A novel early streamer emission (ESE) lightning air terminal system is designed and fabricated. By comparing the intercepted artificial lightning striking numbers of the new ESE lightning protection device and the conventional lightning rod (CLR) lightning protection device in laboratory, the effectiveness of intercepting the artificial lightning strokes by the new ESE lightning protection device is superior to that by the conventional lightning rod lightning protection device. A modified Tesla Coil (TC) discharging by powering AC voltage up to 650 kV with the controlled triggering function generator is used to produce simulated lightning strokes. The top tips of both devices in the same horizontal plane are placed at the same distance to the modified TC during all the test processes. Exchanging their positions makes no obvious difference between the recorded results. The test data validate the effectiveness of the new ESE lightning protection device under the laboratory environment.

Discussion on "Experimental demonstration of the effectiveness of an early streamer emission air terminal versus a Franklin Rod" [and Reply

The paper [1] reports on comparative experiments on a triggered-gap electrode used as an early streamer emission air terminal, with some equivalent circuit analysis of the triggering circuit and simplified electric field calculations.

Experimental demonstration of the effectiveness of an early streamer emission air terminal versus a franklin rod

This paper is devoted to a detailed presentation of all aspects involved in a novel experimental technique to prove the effectiveness of an early streamer emission air terminal (ESEAT) versus a traditional Franklin rod in a laboratory. Firstly, a theoretical basis for the equivalent-circuit analysis of an ESEAT model is presented. It is shown that the dynamic electric field intensity on the active ESE rod is higher (theoretically even twice as high) than the static field intensity of the conventional Franklin lightning rod. Then, an experimental test using a method and associated with an electrostatic simulation demonstrates the effectiveness of an ESEAT (Pix3-60 from Piorteh Company) versus a conventional Franklin rod in the SIAME laboratory of the University of Pau in France. This method consists in locating both the ESE terminal and the Franklin rod together in the same configuration in accordance with the French Standard NFC 17-102 (09/2011). During the tests, all discharges were recorded on the ESEAT manufactured by Piorteh Company when its rod was active. This experimental test could be used on any kind of lightning protection device.

EFFECT OF CORONA DISCHARGES ON THE INCEPTION OF POSITIVE UPWARD LEADER-STREAMER SYSTEM

The critical-charge criterion of the stem-leader transition and the shielding effects of space charges on the streamer inception are two most contested issues on the inception of positive upward leader–streamer system (LSS). In this paper, a series of simulation experiments on the LSS inception were designed and carried out. A new critical-charge criterion in the range of 0.2–0.3 μC was proposed, and the previous criterion of 1.0 μC was proved to be harsh. The shielding effect of positive space charges on the streamer inception was verified directly by the experiment results. A theoretical formula for calculating the LSS inception voltage by the first-corona inception voltage was obtained. An appropriate first-corona inception time for getting an earlier LSS inception was proved to be existent. At last, the effects of the so-called improved lightning rods, such as the early streamer emission rod (ESE) and the controllable lightning rod (CL), were discussed, and it seemed that they would not help to extend the protective zones of the lightning rods.

Failure of the Collection Volume Method and Attempts of the ESE Lightning ROD Industry to Resurrect it

To facilitate the marketing of their devices, the vendors of Early Streamer Emission (ESE) lightning rods are attempting to get the Collection Volume Method (CVM) in IEEE Standard 998 which deals with the Shielding of Substations. This attempt follows their failures before IEC, Standards Australia and the NFPA (National Fire Protection Association). Voting on the standards of the IEEE is done by a pool of persons, most of whom are not lightning experts. The same applies to potential buyers of ESE devices who are being wooed by use of the CVM. This paper seeks to enlighten those persons by using indisputable field observations to prove invalidity of the CVM. The paper also shows that development of the CVM rested on a false perception that discrepancies existed between field observations and predictions of the Electrogeometric Model (EGM), and that the CVM failed to address those claimed discrepancies.

Lightning protection: challenges, solutions and questionable steps in the 21st century

Besides the special primary lightning protection of extremely high towers, huge office and governmental buildings, large industrial plants and resident parks most of the challenges were connected to the secondary lightning protection of sensitive devices in Information and Communication Technology. The 70 year history of Budapest School of Lightning Protection plays an important role in the research and education of lightning and development of lightning protection. Among results and solutions the Rolling Sphere designing method (RS) and the Probability Modulated Attraction Space (PMAS) theory are detailed. As a new field Preventive Lightning Protection (PLP) has been introduced. The PLP method means the use of special preventive actions only for the duration of the thunderstorm. Recently several non-conventional lightning protection techniques have appeared as competitors of the air termination systems formed of conventional Franklin rods. The questionable steps, non-conventional lightning protection systems reported in the literature are the radioactive lightning rods, Early Streamer Emission (ESE) rods and Dissipation Arrays (sometimes called Charge Transfer Systems).

Laboratory experiments cannot be utilized to justify the action of early streamer emission terminals

The early emission of streamers in laboratory long air gaps under switching impulses has been observed to reduce the time of initiation of leader positive discharges. This fact has been arbitrarily extrapolated by the manufacturers of early streamer emission devices to the case of upward connecting leaders initiated under natural lightning conditions, in support of those non-conventional terminals that claim to perform better than Franklin lightning rods. In order to discuss the physical basis and validity of these claims, a self-consistent model based on the physics of leader discharges is used to simulate the performance of lightning rods in the laboratory and under natural lightning conditions. It is theoretically shown that the initiation of early streamers can indeed lead to the early initiation of self-propagating positive leaders in laboratory long air gaps under switching voltages. However, this is not the case for positive connecting leaders initiated from the same lightning rod under the influence of the electric field produced by a downward moving stepped leader. The time evolution of the development of positive leaders under natural conditions is different from the case in the laboratory, where the leader inception condition is closely dependent upon the initiation of the first streamer burst. Our study shows that the claimed similarity between the performance of lightning rods under switching electric fields applied in the laboratory and under the electric field produced by a descending stepped leader is not justified. Thus, the use of existing laboratory results to validate the performance of the early streamer lightning rods under natural conditions is not justified.

The striking distance of lightning flashes and the early streamer emission (ESE) hypothesis

The attachment of a lightning flash to a lightning conductor (or to any other structure) takes place through a connecting leader that rises from the structure towards the descending stepped leader of a lightning flash. The spatial separation between the tip of the stepped leader and the lightning conductor (or the grounded structure) at the initiation of the connecting leader is known as the striking distance. In this paper the striking distance of stepped leaders is derived as a function of conductor height, conductor radii and the prospective return stroke current. Based on these results the validity of the early streamer emission (ESE) hypothesis is discussed. According to the ESE hypothesis, the striking distance of a lightning conductor can be increased by the artificial initiation of streamers from a lightning conductor. The results cast doubt on the validity of the ESE hypothesis. This in turn calls for more experimental data and field validations before using the ESE hypothesis in standard lightning protection practice.

A CRITICAL REVIEW OF NONCONVENTIONAL APPROACHES TO LIGHTNING PROTECTION

The conventional technique for the lightning protection of structures is described in the U.S. National Standard, NFPA 780, and in many other national and international lightning protection standards. Two nonconventional techniques, known generically as “lightning elimination” and “early streamer emission,” are claimed by their proponents to be superior to the conventional lightning protection technique. We review the literature on these nonconventional approaches as well as the pertinent lightning literature and conclude that the suggested superiority of the nonconventional techniques over the conventional method is not supported by the available experimental data or by theory.

Comment: New investigations of the ‘early streamer emission’ principle

N.L. Alien and J.C. Evans have presented a new experimental investigation regarding the physical behaviour of'early streamer emission' (ESE) devices (2000). The authors addressed a most important issue and succeeded in performing a most complex experiment. Complex experimental arrangements require care and clarity in the presentation of the experimental results. Two remarks are raised regarding the design of the experiment and the interpretation of the results. The remarks are based on author's own experimental work and numerical simulations of a similar arrangement, namely the case when a high-ohmic series resistance inhibits the discharge. The aim ot the remarks is to contribute to the understanding of how and to what extent ESE devices differ from ordinary Franklin rods in general and to the appropriate interpretation of the results by Alien and Evans in particular. The reply of the N.L. Alien and J.C. Evans is appended.

Reply: New investigations of the ‘early streamer emission’ principle

Reply: New investigations of the ‘early streamer emission’ principle

New investigations of the ‘early streamer emission’ principle

An ‘early streamer emission’ (ESE) terminal, for lightning protection, stimulates a burst of streamers from its tip before producing streamers induced by the field of a downward leader, approaching from a thundercloud. It has been claimed to enhance the probability of attachment of a lightning channel to a protection system. Experiments are described in which the performance of a simulated ‘early streamer emission’ terminal has been characterised. A negative slow-front impulse voltage has been applied to a plane suspended over a vertical rod to simulate the rise of electric field at the tip of the rod, which would be caused by an approaching leader discharge from a cloud. A positive auxiliary voltage impulse, of profile 1/30 µs, of sufficient amplitude to produce corona, has been applied independently at the rod at controlled, variable times during the rise of the slow-front field. The effects of this pulse on the corona produced at the rod by the negative impulse at the plane, on the breakdown voltage of the gap, and on the times to breakdown have been recorded. The general conclusions drawn are that the auxiliary corona has insignificant effects on breakdown when it is applied during the streamer phase of the slow-front corona, but that it influences growth when applied after the leader has been initiated by the ambient field.

Early streamer emission lightning protection systems: An overview

Early streamer emission (ESE) lightning protection systems are a relatively new approach to the perennial problem of lightning damage, and these systems may hold promise for a more effective protection against lightning. However, the scientific and technical basis for this improved performance is far from certain and the efficacy of these technologies remains open to question. In this paper we examine the physical basis for ESE devices and identify areas of controversy and gaps in our knowledge of lightning and lightning protection that need to be considered in assessing ESE devices and in their future development.