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The experimental results that are presented in this paper show that there is a statistically significant influence of floating electrodes on rod-rod air gap breakdown under impulse current, when the floating electrode is close to either of the electrodes. The results are extrapolated to explain the influence of electrical floating metal parts in lightning side flashes, where the arcing distances are not that long. The experimental outcomes are still inconclusive with regard to direct lightning strikes where the final jump may be a gap of few hundred meters.

Split factor is a fundamental consideration when designing a distribution substation earth grid. Arbitrary choice of split factor in earth grid design process may lead to technical and economic implications resulting in underestimated or overestimated designs. In this paper, a distribution substation earth grid was designed using SESCAD and executed in MALT module of CDEGS. The energization current was varied by 100%, 75%, 50% and 25% of the short circuit current available at the secondary terminals of the upstream transformer to determine the impact on safety criteria of the earth grid. Results indicated that, the EPR for 100% fault current was higher, whereas the step and touch voltages were lower. It was also revealed that, there was no difference in step and touch voltages when energization current was set at 75%, 50% and 25%.

This paper addresses a concurrent burning issue in Uganda; the mitigation of rapidly increasing lightning hazards in the country. By analyzing various economic, technical and social factors a feasible hazard mitigation module has been proposed. The module essentially needs government intervention for providing facilities and coordination of various contributors and stakeholders for channeling expertise and possible funding. Several lightning disaster mitigation strategies have been proposed whereas practicality and limitations of applying them in Uganda are discussed in detail. Proposed modules are applicable in many countries having similar socio-economic environment

This paper presents preliminary studies on the lightning accident details in Burundi, a landlocked country in East Africa. The reported lightning incident record in 2012 and 2013 depicts that there are 52 human deaths, 94 human survivals with injuries and 40 deaths of livestock. Makamba province recorded the highest human casualties with 14 deaths and 69 injuries whereas Nyanza-Lac commune of the same province topped the list with 8 deaths and 52 injuries. The statistics do not justify the 1:10 ratio of death: injury as it is reported in USA. The statistics may be a gross underestimation as many lightning accidents are not reported due to lack of communication, especially in the rural areas. Gomes-Kadir equation estimates the death rate as 52 per year, a figure twice as high as that was observed in this study. The analysis of information for incidents over few more years reveals that seeking shelter under ungrounded metal-roofed buildings is extremely dangerous as multiple deaths may occur in the event of a lightning strike to the roof.

This is one of the first scientific investigations on lightning current and voltage distribution along Buddhist Stupa in Sri Lanka and elsewhere. Such distribution provide vital information on lightning safety concerns of people and objects outside the structure as the building is totally sealed. The metal casket of which the block of quartz is installed at the pinnacle of the Stupa, may act as the point of interception with lightning stepped leader. Large hemi-spherically symmetric outer structure of the Stupa causes uniform distribution of current over its surface. Such distribution yields very low current density thus possibilities of side flashing or localized heating are minimized. Structure of the Stupa was analyzed as a collection of lumped circuit elements using MatLab and SimuLink software to show that there will be no dangerous potentials developed within possible arcing range to the surrounding, in the application of impulse current. Thinly distributed current, driven into the deeply laid foundation of the structure, prevents development of significant step potentials in the vicinity that could pose danger to the devotees.

Information by the media in advance of severe weather occurrences can prepare the public to respond properly during an emergency situation. At the same time, the media should work as a channel to communicate and promote proper public response to severe weather threats. The objective of this study is to examine the position of the media as a tool of communication and education on severe weather in Malaysia. Results indicate that the present role of the media in Malaysia is still insufficient in communicating and educating the public on severe weather.

The objective of this study was to examine the influence of socio-demographic factors on severe weather concern, knowledge and preparedness among urban and semi-urban residents of Malaysia. Results indicated that a broad-based education approach could be used to enhance community preparedness to severe weather risks as age, education level, gender and ethnicity did not influence all the variables of the study.

The minimum separation between a human body and 10 m high objects struck by lightning, to avoid side flashes, has been studied. Objects with different materials and cross sectional areas have been considered. The parameters of lightning current waveform used in this paper are those pertinent to negative subsequent strokes given in IEC 62305-1 (2010). Since the minimum separation between a human being and an object struck by lightning is related to human safety, the worst case scenarios are considered. The distance between a two meter tall human being and the object struck by lightning is varied and the distribution of electric field around the object was calculated. Consequently, we computed the minimum separation between the human body and the lightning struck object with a range of values of resistivity and cross sectional area so that the probability of side flashing during a lightning strike have been discussed.

Connecting distributed generation (DG) units to the distribute networks impose several impacts on it which have not been considered in conventional fault location algorithms. This paper presents an accurate fault location technique for unbalanced radial distribution networks based on evaluating measured values of short Circuit Current (S/C.C) at the source bus with a designed Multi-Layer Feed Forwarded Neural Network (ML-FFNN). The estimated locations of different fault types are compared with the actual distances and Average Difference Percentage (ADP) is calculated for each fault type. The designed neural network is able to work with small scale datasets. Hence the proposed method can be implemented in the real distribution networks.

This paper presents a novel accurate fault location technique for the radial unbalanced distribution systems, based on measurement of the Short Circuit Power (S/C.P) peak values at the substation. To evaluate the gathered dataset, a Multi-Layer Feed Forward Neural Network (ML-FFNN) with the tuned parameters is designed and the locations of faults are estimated in low, medium and far distances from the source. The estimated distances are compared with the real fault locations to show the accuracy of estimations. The proposed method can work with the small scale datasets and it is capable of being implemented in distribution systems with several laterals.

Lightning current is an important parameter that has to be considered. The different behaviour of lightning current depends on the way the lightning strikes either as a direct or indirect lightning strike. In this paper the modelling of the current as a result of a direct strike of lightning on a tall structure is considered. A few of up-to-date on current models, current functions, reflection factors, the return stroke velocity (RSV), the general equation representation of this case are reviewed. Also, through MATLAB software, the results of a case study are generated. The results show a good agreement with the measured values. In addition, the behaviour of the lightning current is evaluated at different heights of the lightning channel with respect to the top and bottom of a tall structure. Also, the lightning current at the top and bottom of the tall structure are observed for different values of the reflection factor. The results show that the peak of the lightning current along different heights of the channel with respect to the top and bottom of a tall structure decreases with increasing height of the channel. Also there is a time delay during the initial time period. Furthermore, the lightning current at the bottom of a tall structure has a high value of peak current and has an attenuation wave shape of current that compares with the lightning current at the top of the tall structure. As a result, this paper may provide benefit in evaluating the electromagnetic (EM) field since the behaviour of the lightning current on a tall structure is known.

Metallic part would play an influential role in the case of probability of lightning strikes. An experimental study has been done to find out the effect of the presence of floating electrode on the body during thunderstorm. Although, it is clear that a small metal part on the body or in vicinity does not have effect during direct strike, the effects has been examined only in the case of side flashing. SPSS has been used to check the statistical significance of the probability. According to the result, floating electrode may shorten the gap distance of the struck point and a human body thus increasing the probability of lightning side flashing. The test has been done covered floating electrode (insulated) as well. Thus, it is recommended to either remove or isolate the metal parts during thunderstorm.

The value of soil resistivity is an essential pre-requisite in designing an electrical grounding system. The current practice, as advocated even by national/international standards involves taking the average soil resistivity of the site as the parameter to be considered in designing the grounding system. This study shows that average soil resistivity may lead to significant overestimation or underestimation in the designing process as the localized soil resistivity may significantly differ from the average soil resistivity of the entire site. At least 14% difference between average and localized soil resistivity were obtained base on measurements done on five locations. Therefore, it is suggested that electrical engineers who design grounding systems should first identify the locations where the components of the grounding systems will be installed. Then, the localized soil resistivity at that particular point should be measured and the sizing and geometry of the grounding electrode should be designed accordingly.

Experimental test has been done due to realize the characteristics of the behavior of voltage-time in the case of rodplane air gap of 70mm and 100mm. Impulse voltage has been applied in this regard to find out the voltage at breakdown level, time to breakdown value, time to complete discharge, comparison of trajectory of the waveshape and the significant points of the increasing the gap distance. The results depicted that, the breakdown voltage was dependent on the integral of applied voltage and discharge time was more dependent on the gap value compared to other conditions.

Design of distribution substation earthing grid can be very challenging in high resistivity soils especially in two layer soils where the top layer resistivity is lower than the bottom layer. This paper presents the design of a distribution substation earth grid using Current Distribution Electromagnetic Field Grounding Soil Structure Analysis Software (CDEGS). Soil resistivity measurement was carried out at the substation site using a 4-pole Megger earth tester based on Wenner method. The soil structure was determined using RESAP module, while the design was implemented using SESCAD and executed by MALT module. Results indicated a slight reduction of earth grid resistance, 0.6%, 5.8% and 6.5%, respectively as the grid burial depth was varied from 0.5m to 1.5m in steps of 0.5m. The touch and step voltages were found to be lower when surface layer material was not applied and higher when surface layer materials of 3000Q-m and 5000Q-m resistivity were interchangeably applied on the grid surface. It was also found that, the calculated earth grid resistance from IEEE Std. 80-2000 equation was lower than the grid resistance computed by MALT.

This paper presents analysis of various potential lightning risk scenarios, especially in less developed communities. We identify that there is no uniform safety promotion module that may be applicable to all communities with success. Hence we develop a hierarchy of hazard control mechanism that may be applicable to any given community with uniform professional or social practices. The hierarchy of control ladder has been integrated with the responsibility distribution network that runs from government level to the potential victim. The mechanism could be adopted by designers of lightning safety promotional programs in many parts of the world by appropriately determining the tools of implementation at various societal and professional levels. It is expected to minimize deaths and injuries as well as property damage due to lightning in vulnerable parts of the world.

Return stroke models have been reviewed according to the assumptions they make and their underlying concepts. We have investigated the roots of the modern concepts used to describe return stroke related phenomena and illustrated their developments and deviations from the original idea. We discuss the return stroke models in two categories in accordance with the direction of the charge transfer along the channel. We show that all the models that we have considered can be described by two general sets of mathematical equations. The validation and comparison of models in reproducing measured lightning parameters are discussed. We also show the different methods employed by return stroke models to estimate the return stroke speed and discuss possible improvements that could be introduced into return stroke models in the future.

The optical radiation and the magnetic field generated by electrostatic discharges are measured, together with their current signatures. The observations show that during the initial growth, the temporal variation of the optical pulse is similar to that of the current. The two waveforms deviate from each other during the decaying part of the discharge, the optical signal having a longer duration. The peak current is linearly correlated with a correlation coefficient of 0.9, to the peak optical radiation. The measured currents were used to calculate the magnetic fields and a good agreement was observed between the measurements and calculations. The results show that both the optical radiation and the magnetic field can be used to sense remotely the currents in electrostatic discharges.

Broad-band optical output (500–850 nm) and channel current of 500 mm long sparks were measured. Experiment was conducted for several current rise times. The optical rise time and current rise time show a linear relationship. During the rising portion the optical signal closely follows the current wave shape. There is no detectable variation in the time separation between the starting point of the optical signal and that of the current signal, with varying current rise time or current amplitude. One can apply this result to use the optical signal, which is measurable, to estimate the information regarding the variation of current with altitude of long spark channels. One such case, that will be benefited from the results of this research, is the measurement of peak current along the channel of both artificial and natural lightning. For a 250 mm gap we performed the experiment by increasing the current amplitude between about 0.5 kA and about 3.5 kA, for the same current rise time. The current rise time and optical rise time remain approximately at a steady level with current amplitude, while the former is always slightly less than the latter. Hence, we suggest that the results obtained in this work may be extended to the measurements of the current along lightning channels where the peak currents are in the range of few tens of kiloamperes. For a given current pulse half-width, that of the optical pulse shows a linear variation with current amplitude. We also observed a linear relationship between the current amplitude and the optical amplitude in the range of current amplitudes relevant to this experiment.

In this paper we have analysed breakdown pulse trains preceding the first return stroke in 47 negative cloud-to-ground (CG) lightning flashes observed in Sri Lanka (tropics) and that in 41 negative CG flashes recorded in Sweden (temperate regions). In the data obtained in Sri Lanka, breakdown pulses could be detected only in nine flashes. In other flashes either these pulses are absent or, if they are present, their amplitudes should be below the background noise level. From the nine flashes with breakdown pulse trains, we obtained the following results. The ratio between the maximum breakdown pulse amplitude and the return stroke amplitude (BP\RS ratio), as a percentage, is 16.5%. The time duration between the most active part of the pulse train and the return stroke (BP\RS separation), is 11.9 ms and the ratio between the noise amplitude and the return stroke amplitude (N\RS ratio), as a percentage, for all 47 flashes, is 5.0%. In the flashes observed in Sweden, breakdown pulses are detectable in all records. In this data, the BP\RS ratio, as a percentage, is 101.4%, the BP\RS separation is 13.8 ms and the N\RS ratio, as a percentage, is 3.7%. All the above values are arithmetic means. Most of the pulses of breakdown pulse trains observed in both countries are bipolar in nature with the initial polarity the same as that of the succeeding return stroke.

Eighteen subsequent return stroke fields from triggered lightning flashes, observed at 5.16 km were used to test the ability of a return stroke model to predict the return stroke peak currents, peak current time derivatives and return stroke velocities from the measured fields. In each example, the parameters of this previously published model were changed until a best fit was obtained for the first few microseconds of the measured field and the final static field change. Once a best fit had been obtained, the corresponding peak current, the peak current time derivative and the return stroke velocity were all compared with the measured values. The mean percentage error (MPE) and the mean absolute percentage error (MAPE) of the predicted current peaks are 6.9 and 11.3%, respectively. The MPE and MAPE corresponding to the predicted current time derivatives are 13.0 and 13.8%, respectively. The model predicted velocities of these eighteen strokes had a MPE of 19.6% and a MAPE of 20.3%. The results show that the method outlined in this paper can be used to extract the return stroke current parameters from the measured electromagnetic fields.

Long distant electric fields (400-500 km), generated by 26 positive cloud-to-ground flashes, were analysed, These flashes consist of well detectable long impulse fields subsequent to the initial pe ...

Lightning protection of oil storage tanks has becomes a controversial subject, due to conflicting protection criteria. One such is the sense of using self-protection criteria, relying on the strict fulfillment of the operational conditions, material thickness and reliable bonding; the other refers to the necessity of standalone lightning protection system (LPS) where air terminals are installed in order to avoid any interception between the lightning stepped leader and the tank body that could cause hot spots and excessive temperature rise. Each method has its own advantages and drawbacks. In this paper these criteria are analyzed with critical view in order to make appropriate decisions in selecting the most suitable method of protection for a given situation.

This paper investigates the effect of design parameters on the induced voltages on a distribution power line. This investigation is based on perfect ground conductivity, single stroke lightning and lightning without branches. The design of the parameters includes, d, the striking distance of the lightning, h, the height of the conductor, and r, the diameter of the conductor, all of which are elements that produce the variations in the induced voltage on a distribution power line with respect to a vertical or an inclined lightning channel. Thus, the outcome of this investigation can act as a guide for utility companies or other power engineers in order to plan an appropriate protection scheme for a distribution power line.

In recent years, the renewable or green energy has been a major focus globally. Moreover, this energy can be like solar and wind which have been increasingly implemented worldwide. However, the adoption of the green energy is still low due to high technological costs and the associated power system issues. The effectiveness of Flexible Alternating Current Transmission System (FACTS) devices in problems that are related to the power systems has been tremendous. Although, there are still relatively limited works on incorporating FACTS devices into green energy plants. The progress of the FACTS application in renewable energy plants has been reviewed in this work. In addition, it has been discovered that FACTS plays an equally effective role in improving the power system quality of green energy plants especially in wind and solar plants. The rate of penetration of green energy could be accelerated if applications of FACTS devices in renewable energy plants were to be more widely adopted.

This paper describes and illustrates the important factors concerning the safety issues of capacitor banks in medium voltage (MV) power system networks. It also explains the protective issues that should be considered. A detailed account on failures and risks of capacitors during the switching operations in power distribution systems is presented. Procedures of safety, techniques of protection, existing solutions to avoid equipment damage, as well as maintaining system safety and reliability have been discussed.

In this paper, the lightning protection requirements of a typical residential building have been discussed and techniques have been provided to protect the building from both direct and indirect damages of lightning, with special attention to the protection of PV panels placed on the roof. These techniques include the designing challenges and also the type of devices which can be used to reduce the surge current flow and magnetic field. It has been shown that for buildings with roof top PV systems only the avoidance of lightning attachment to unprotected parts of the building is not sufficient. Lightning currents passing through the lightning protection system may still affect the PV power system through inductive coupling. Hence strategic placement of PV systems and shielding of conducting systems wherever possible has been recommended. It has also been envisaged that the impact of lightning on PV systems is directly related to the isokeraunic level of the region and elevation of the building. Several recommendations have been proposed in designing the air termination system for a roof with PV panels in high isokeraunic regions. Finally the building integrated photo voltaic (BIPV) projects which are conducted in Malaysia have been evaluated..

As the demand for power increases, reduction of undesired energy during the transmission and distribution of electrical energy becomes a vital issue. In this respect corona will play an important role in the near future. Loss of energy due to corona is governed by both power line properties and environmental factors. In order to address corona related issues, electrical designers should have a good knowledge on corona generation and the effects of corona under various conditions. Methods developed during the last many decades to minimize corona effects, have their own advantages and disadvantages. This study discusses in detail these methods with the view of providing information to develop new methodologies to overcome the drawbacks of present corona prevention techniques.

Lightning can create lightning induced overvoltage (LIOV) on a power line. However, detailed considerations are needed concerning the evaluation behaviour of LIOV due to changes in channel angle which is referred to as an inclined lightning channel. The aim of this paper is to evaluate the behaviour of LIOV due to variations of channel angle. The LIOV was generated through the execution of an algorithm in MATLAB. Results indicate that the behaviours of LIOV are direct and show a linear relationship with an increasing channel angle which is an inclined angle and observation point angle. On the other hand, the effect on the LIOV of an increasing channel angle due to the return stroke velocity decreases at the highest velocity. As a result, the outcome of this paper could be useful for electrical power designers for the fast estimation of LIOV peak voltages without recalculation of the LIOV and to assist in the appropriate planning of protection schemes.

Effects of surrounding environment of grounding electrode locations on the performance of overall grounding system has been studied. Copper rods were buried at 25 different locations with various environmental settings and their respective variations in grounding resistance were monitored for up to 4 months. It was found that there is a clear dependence of grounding resistance on the condition of surrounding environment, in addition to the average soil resistivity. Installation of grounding electrodes near running waterways, huge trees as well as slopes should be avoided wherever possible as the ground resistance of electrodes in such environments may fluctuate significantly with time.

Due to environmental issues and the upward trend of fossil fuel prices, the study of renewable energy (RE) based generation and their effects on the electrical system has become an important part of the government's energy policies and university projects. In RE generation, as solar photovoltaic (PV) systems are modular, silent, and transportable and demonstrate ease of installation, they have attracted a greater amount of attention specifically in those areas which receive considerable average solar radiation per day such as Malaysia. However, connecting solar PV farms to the grid like any other distributed generation (DG) units poses serious issues which arise in the distribution network. This paper presents a novel fault location algorithm based on the recording of short circuit power values at the primary substation of unbalanced radial distribution networks including PV systems. The recorded values are evaluated by a designed and tuned multi-layer feed forward neural network and the fault distances from the source are estimated accordingly. In order to highlight the accuracy of the presented method, the scenario is also repeated by recording the peak values of short circuit current which have been mostly used in the published intelligent fault location studies and the obtained results via two different values are compared with each other. The results reveal that the presented algorithm using a small scale input set is able to precisely locate different fault types in the unbalanced distribution networks including DG units.

The necessitation in the optimal power demand model, make it an impetus to present this work as a glaring path in determining the optimum power demand curve, using the available data of a substation. The data are used to find the equation and its coefficients of determination that can give the best-fit curve of the power demand of a substation, based on the available data. This will produce a model that can be validated by comparing the data and figured out the equation.

Characteristics of surface flashover in the presence of different dielectric materials have been investigated. Lightning voltage impulses (1.2/50 µs) have been applied to a rod-plane gap of 250 mm, bridged by cylindrical solid dielectrics with circular cross-section of 10 mm. The materials used are polythene, polymethyl methacrylate (PMMA), and polyvinyl chloride (PVC). The characteristics of breakdown are compared with those pertinent to a similar rod-plane air gap. In each case, 50% breakdown voltage was found for both polarities. Then for each material 10 impulses were applied at 100% breakdown voltage for each polarity. The results show that there are three different types of paths taken by the discharges; they are the discharges that leap out of the rod at the HV triple junction (type-A), those follow the surface for a certain length and then leap out of the surface (type-B) and those entirely follow the surface (type-C).

Lightning related accidents in Nigeria, a country of high lightning density, have been collected and analyzed. Results show that lightning related human injuries and deaths are very high in Nigeria, where the actual figure may reach as high as 500 deaths per year. However, due to the social stigma attached to lightning incidents and the lack of unbroken news chains reaching media, collection of accurate statistics has become a daunting task. Apart from human and livestock related hazards; property damage is also of high concern due to probable devastating consequences of such incidents. Extra attention has been paid on collecting damage records related to aviation industry as there are several serious accidents related to lightning have been reported in this area. The data collected and analysed is used to develop a set of national level recommendations for lighting safety and protection which can also be applicable in neighbouring countries, as they also experience extremely high lightning occurrence density.

This is the first investigation and analysis of lightning related incidents in Zambia. Two case studies on both human injuries and equipment damage at five sites are reported. Lightning injuries were mostly attributed to the lack of proper structural protection systems, although lack of awareness among the public may also contribute to the situation. Many injury mechanisms, including unsuccessful upward streamers, may cause injuries. Design of lightning protection schemes should take social structures and affordability by the affected public into account. Losses in the power sector are excessively high in the region and seriously affect the operation of both business and domestic life. Replacement cost incurred by the power companies can be prohibitive. Lightning density and pattern in the localized areas, grounding systems of the installations, and specification and installation techniques of lightning arresters should be revisited in giving proper solutions to transformer and power line failures.

This paper focuses on the behaviour of dry sand, bentonite and cement under different voltage conditions. These three materials play important role in electrical grounding systems, in controlling ground impedance of an electrode. However, most often the low frequency earth resistance measurements of grounding electrodes encased in these materials have been considered as the performance indicator. It has been found in this study that the behaviour of materials grossly depends on the applied voltage waveform and repetition of application or duration of the waveform. Time to breakdown in the case of bentonite is considerably smaller than that of cement. Bentonite also shows breakdown in two phases, in the voltage time curve. In cases of both bentonite and dry sand, fulgurites were formed in the application of short duration alternative voltage at 50 Hz. As fulgurites are very high in resistance compared to the original material, the overall resistive and inductive behaviours of the earth electrodes may change in the presence of leakage currents in MV and HV systems.

Theoretical calculations have been done for determining the low frequency earth resistance of a set of individual electrodes, once the electrode dimensions, installation geometry and soil resistivity profile are given. Accuracy of theoretical estimations was tested by taking measurements of 25 electrodes installed at various soil conditions and environments. It has been found that in most of the site locations, especially vegetation and built-up environments, model predictions deviate considerably from measured values. Three dimensional soil resistivity map of a given land mass is essentially needed in predicting the final earth resistance of a given electrode system. Existing models are not able to produce the large variation in earth resistance, specifically due to the non-uniformity of soil resistivity and probably due to the contact resistance between electrode and surrounding soil. The outcome of this study will immensely be helpful in designing earthing systems for a given installation even at pre-construction stage.

This paper investigates the influence of inclined lightning channel on induced voltage on the line. The angle variations of inclined lightning channel may cause the voltage to be induced at different values for different points along the power line. This behaviour may affect the line's lightning performance if the peak of induced voltage is greater than the critical flashover voltage (CFO) of the line. This induced voltage is expected to be increased when the inclined angle with respect to the observation point is decreased. Appropriate method of induced voltage algorithm with respect to the incline lightning channel will be developed and compared with other method. The outcome of this study would be useful for the utility for their planning and selection of appropriate protection scheme for the line.

Seventeen communication towers and their neighbourhood have been investigated for lightning threats. There is no credible evidence to conclude that the presence of a tower gives rise to increment of lightning occurrence density or direct strikes to the neighbourhood due to the presence of medium height communication towers. However, there is a realistic risk of step potential hazards and equipment damage in the neighbourhood of the towers due to GPR, transfer of transient through power system and induced effects. It is recommended improving the earthing systems at tower site, transformer and power system of the buildings in the neighbourhood and installing of coordinated system of SPDs at all buildings fed by the transformer. We also emphasize that physical distance to the tower should not be the sole criteria to determine the lightning threats to a building close to a tower. Furthermore, there are many misconceptions among the public on lightning and towers. As these misconceptions may dilute the real issues, the public should be made aware of the scientific background of this scenario.

It is a fact that Malaysia encounters more than 70% of power outages due to lightning and it is known as the “Crown of Lightning” in the world. The effects of lightning on electrical/communication networks and structures account for equipment damage, downtime/data losses and malfunctioning of control and automated systems that may cost the nation over RM 250 million and thousands of human injuries and deaths. Good statistics about death and injuries around the world are just beginning to be collected. This paper presents an update of the statistics on lightning fatalities in Malaysia and some comparisons with other countries around the world. In addition, a case study that accounts the geographical location, lightning detection data and distribution system layout will be presented.

This paper addresses the lightning safety environment in Uganda that requires urgent and serious attention of the international expert community. We present recent statistics of reported lightning incidents in Uganda which show that the number of injuries and deaths are overwhelmingly high during year 2011 thus the situation can be declared critical. During the five-year period from January 2007 to December 2011, there were 91 reported lightning accidents which accounted for a total number of 150 deaths and 584 cases of personal injuries to which the victims did not succumb. Out of 150 deaths 95 reported in 2011. The actual number in each case may be much higher as many deaths and injuries go unnoticed due to lack of communication between rural communities and government authorities or media sources. The detailed analysis of several incidents reveals that injuries and deaths are basically due to both lack of awareness and absence of proper protection and safety schemes. The decisive factors of the ill-effects of incidents are time of the day, month of the year, part of the country, location of the incident etc. Most of the accidents have occurred either in the afternoon or in the evening. A spread of incidents can be seen throughout the six month period from June to November with June as the month of highest reported deaths. The highest number of incidents has been reported in the Northern Province of the country. Interestingly, the highest number of incidents, deaths and injuries has occurred while the victims were inside permanent structures. After analyzing these incidents a stepwise procedure is proposed to curb such incidents in the future.

This paper reports and analyses somewhat rare observation related to lightning. In several occasions a large number of Climbing Perch or Koi fish (Anabas testudineus) were reported dead after ground lightning events, in set of commercial fish ponds in Bangladesh. In ponds where several other fish varieties are farmed, only Koi fish is affected. The farmers and neighbourhood attributes the deaths to the erection of a mobile communication tower in the proximity, as the number of affected fish increases as one moves towards the ponds adjoin the tower. Site visits and interviews revealed various facts related to the incident. We show that nearby lightning to a structure having large ground resistance may lead to surface current that provide sufficient lethal energy to kill a fish that swims in surface water.

Earth resistance of buried steel cages, encased in bentonite mixed concrete has been investigated. A reference pit was constructed with steel cage encasing in ordinary concrete. The land mass of the site has somewhat uniform surface soil resistivity which is in the range of 100 Ωm. The performance of earth resistance in each electrode has been measured for five months. The results show that for the first month, the lowest earth resistance and the highest decrement in earth resistance are shown by the pit with concrete having 20% bentonite. However, for the following four months, pits with bentonite mixed concrete showed increased earth resistance compared to the reference pit. These results indicate that the long-term reduction in earth resistance in electrodes encased with bentonite, as observed in previous studies, is not the case with electrodes embedded in bentonite mixed concrete. The initial reduction of earth resistance observed at pits with bentonite mixed concrete may most probably be due to the presence of hydrated bentonite which is not mixed with other constituents of concrete. Other than the pits with 20% and 70% bentonite, the outcome of this research thus far reaffirms the capability of concrete blocks to maintain earth resistance with small fluctuation.

Sri Lanka, a tropical island in the Indian Ocean, experiences relatively high density of lightning. The island has a record of lightning research and lightning education programs that dates back to several decades. Lightning research in the country has a number of measurable outcomes; however, there are no indicators to evaluate the success rate of awareness programs. This paper summarizes the activities pertinent to lightning research and education carried out in the country so far and analysis of information gathered during the recent times on public opinion on various critical safety and protection issues. Consequently, based on the outcome of analysis new modalities are proposed for countries with similar lightning density and social structure to launch lightning education programs with success.

The return stroke velocity is an important factor for evaluation of lightning electromagnetic fields. Measurements showed that the return stroke velocity is varied at different heights along lightning channel while it is usually entered into field calculations with a constant value in previous studies. This paper presents the analytical electromagnetic fields expressions due to vertical lightning channel where velocity profile along channel is considered. The proposed fields expressions can be used to estimate electromagnetic fields directly in the time domain (without needing to apply any extra conversion to Frequency domain) whereas they are based on Heidler current function and can support widely used engineering current models. Likewise, the proposed field expressions are applied on a typical measured profile of velocity and also a function of velocity profile and the evaluated fields are compared to the corresponding simulated fields based on constant value of velocity and the results are discussed accordingly.

Grounding issues related to lightning currents have been addressed giving special attention to recommended practices in IEC 62305 (2010). Unambiguous recommendations are needed for the requirement of type A system or type B system or both systems for a given installation. Specifications of the length of conductors, based on the level of protection, were critically analyzed emphasizing the human risk related issues. Calculations reveal that at Level III and IV, the specified lengths of type A conductors may give step potentials, especially in highly resistive soils that may drive currents through human beings in the vicinity, exceeding lethal energy. Furthermore, specification of the limiting value of resistance for transient grounding systems may lead to hazardous situations as the difference between frequency dependent impedance and low frequency resistance may increase to very high values at Mega Hertz range where lightning energy spectrum has significant amplitude. Covering of a sizable surface area surrounding the grounding conductors with insulation material, is recommended as a practical solution to this issue.

This paper discusses various practical difficulties of implementing internationally and nationally recognized lightning protection standards on small shelters. In aiming to minimize human injuries and deaths due to lightning related accidents for people who take shelter in unprotected structures during thunderstorms, this study proposes out-of-the-box solutions that may save many lives in societies that cannot afford packages of total solution. However, the proposed protection schemes can be applied even in developed countries or wealthy societies where strategic problems such as remoteness of the sites of concern and practical solutions beyond the peripherals of standardized recommendations are demanded. It should be noted that these are last resort solutions rather than replacement for recommendations in international standards.