Lightning Protection Research Articles

Investigation of Induced Overvoltages on DC Cables of PV System Subjected to Lightning Strikes Using FDTD Method

Due to installation of photovoltaic (PV) panels in outdoor areas, they are subjected to lightning strikes which may cause degradation or complete damage, resulting in service interruption and added cost. Hence, it is crucial to provide an efficient and effective lightning protection system which requires some considerations to increase its efficiency and reduce its cost. Any damage to the PV system inverter causes service interruption, so it is important to analyze the transient voltages induced on the dc cables connected to the inverter during lightning strikes. In this article, the induced voltages on dc cables are calculated using the finite difference time domain (FDTD) method, which introduces high accuracy in transient studies. Important factors affecting the transient voltages on dc cables are studied, including the effect of lightning strike polarity and changing the separation distance between the PV panel and the isolated protection system. Moreover, the effect of modifying dc cable arrangement is studied, in addition to the impact of concrete foundation presence in the grounding system. Then, some recommendations are proposed which succeeded in reducing transient voltages on dc cables. In addition, the induced voltages calculated by FDTD are compared with those obtained by partial element equivalent circuit method.

Parameters of the Initial Continuous Current of Negative Upward Lightning Measured at the Peissenberg Tower, Germany, From 1992 to 2022

In this article, we analyze the parameters of the initial continuous current (ICC) of the negative upward lightning measured at the Peissenberg Tower, Germany, from 1992 to 2022. A total of 54.9% of them were ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Only</sub> -flashes (without significant ICC-pulse), 24.0% of them were ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RS</sub> -flashes (with subsequent return stroke), 19.6% of them were ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</sub> -flashes (with ICC-pulses > 2 kA), and 1.5% of them were ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Bipolar</sub> -flashes (succeeded by a positive current component). The analysis revealed that the ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Only</sub> -flashes were the weakest ones, the ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</sub> -flashes were the strongest ones, and the ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RS</sub> -flashes and the rare ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Bipolar</sub> -flashes were in between. Out of the total of 204 measured ICCs, 16 (7.8%) of them exceeded the charge of 200 C, which represents the highest tolerable level according to the lightning protection standard IEC 62305-1. The strong ICC <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</sub> -flashes carried charges up to 454 C, being more than twice of this tolerable level.

A protocol for selecting viable transmission line arrester for optimal lightning protection

Direct lightning strikes on overhead lines and towers causes power system outages. Optimal surge arrester placement is a practical and economical protection technique. From research trends, three types of transmission line arresters are in practice: Non-Gapped Line Arrester (NGLA), Externally Gapped Line Arrester (EGLA) and Multi Chamber Insulator Arrester (MCIA). This study proposed a simplified guide for selecting the most suitable line arrester considering the placement configurations, double circuit outage prevention and energy capabilities. Electromagnetic Transient Program was implemented to analyze back flashover performance of a typical 275 kV double circuit transmission line in Malaysia. Critical flashover parameters considered are lightning current magnitude, tower footing resistance, and power frequency angle. Analyzed results from the three arresters found that installing four arresters, two per circuit, at the lower and upper phases respectively, is the most optimal and universal double outage mitigation technique. Energy comparison reveals that MCIA discharges 54% and 44% less energy than NGLA and EGLA respectively. Also, from 132 kV system results, MCIA discharges 74% and 22% lesser energy respectively. From further validation of the simulation model, NGLA discharged 23.8% more energy than EGLA from experimental results. The proposed guide is applicable to double circuit lines below 275 kV.

Lightning current analysis for tall tower strike using 3D FEM

In this study, the lightning current waveforms at the middle and bottom positions for 60 m tall tower strikes were observed using the three-dimensional finite element method (3D-FEM). When creating the model for lightning current waveform analysis at the middle and bottom positions of towers, base current speed and ground conductivity characteristics were taken into account. The model was developed using scattering boundary conditions to avoid wave reflections and limit computation time. We have considered ground conductivity of 5.98 e7 S/m, 0.1 S/m, and 0.01 S/m, respectively, in our model. Base current speeds were considered in our model to be equal to the velocity of light, half of the velocity of light, and one-third of the velocity of light, respectively. This investigation will aid in developing a lightning protection strategy and a better understanding of the properties of lightning.

Multiple wind turbines shielding model of lightning attractiveness for mountain wind farms

In this study, a lightning attractiveness assessment method was proposed for mountain wind farms (WFs). A full-size wind turbine (WT) model accounting for terrain topography was established. Then, the lightning collection area (LCA) of WTs was calculated using the self-consistent leader inception and propagation model (SLIM). Finally, a quantitative relationship between terrain structure and the LCA of a WT was obtained, and a shielding model was incorporated to realize differentiated lightning attractiveness assessment of WFs. Results showed that higher terrain height and steeper ground slope angle both increase the size and the height of the LCA, meaning that lightning attractiveness can vary because of terrain differences, even for WTs with the same elevation. The influence of ground slope angle on the LCA showed a saturation trend. The variation of the LCA was analyzed based on the distortion effect of the terrain structure on the electric field. By comparison, the simulation results of lightning attractiveness for mountain WFs in this paper are in good agreement with the actual observation results in flat and mountainous areas. The proposed model could be used to identify weaknesses in the lightning protection of mountain WFs.

Evaluation of Time, Cost, and Factors Causing Delay of Grounding and Lightning Protection Installation Project

The problem faced by one of the private construction companies in Jakarta, Indonesia is the delay in completing the grounding and lightning protection installation project. This delay resulted in both material and immaterial losses for the company. Factors that are thought to cause delays in this grounding and lightning protection installation project include man, machine, material, and environment factors. The method used in this research is the Critical Path Method (CPM) and Crashing method to accelerate the project duration and determine the effective time and cost that can be used to complete the grounding and lightning protection installation project and the root cause analysis method with fishbone diagrams and 5 why analysis as tools to find out the root causes of problems and formulate corrective actions that may be taken by the company. The most effective and efficient acceleration alternative in terms of time and cost that can be applied by the company is the alternative of additional labour. The additional labour alternative is able to reduce the duration of work with the smallest additional cost compared to other alternatives. Meanwhile, the factors that cause delays in project work can be seen from the root causes of each factor. The root cause of each factor is then used as the basis for formulating corrective actions that can be taken by the company.

Power Efficiency Analysis based on Lightning Effect on Large-Scale Solar Photovoltaic System

Currently, a large-scale solar photovoltaic (LSSPV) has become one of the fastest developments of electrical generation power for Malaysian Renewable Energy. However, lightning strikes are common in Malaysia due to its geographical position and tropical climate, especially in the open space of large-scale site power plants. This paper discussed the scientific basis and key assumptions that should be included in the layout of a lightning protection scheme in a large-scale solar photovoltaic installation. The framework proposal aims to ensure compliance with standards and guidelines, mitigating the risk of significantly induced currents in the LSSPV power plant. A 2.5 MW solar PV farm system was modelled using MATLAB software for assessing a solar PV farm’s electrical performance under various lightning current waveforms and lightning magnitude currents. These lightning strikes will impact photovoltaic modules, thus deteriorating the system’s ratio generation. The effects of lightning current on LSSPV were accessed based on simulation work in MATLAB Simulink. The induced current protection scheme covered rating selection and collecting data on lightning that may hit the modules or arrays. This data was then analysed according to the standard guidelines to ascertain the most effective protection measures for the 50MW PV farm within the LSSPV system. Minimising the maintenance and replacement cost of equipment is possible. The performance of a 2.5MW solar PV power plant with a grid connection was evaluated. A maximum and minimum power output of 2.47MW and 522.50kW, respectively, were observed. However, when the lightning impulsive current is included through the system, the power output decrease to 407.33kW due to the high magnitude induced.

Perencanaan Sistem Penyalur Petir Eksternal Pada Gedung SMK Sultan Agung 1 Tebuireng Jombang

Lightning is a natural phenomenon that can damage buildings. There is a solution to dealing with damage from lightning strikes, namely by installing lightning protection. Lightning protection consists of termination rods, distribution cables and earthing, from the results of analysis and calculations at the Sultan Agung 1 Tebuireng Vocational High School building, Jombang requires a total 11 termination rods, 2 distribution cables for each building and 2 rods planted 3 meters deep with a distance of 15 meters so that the grounding value is below 5 ohms

Mitigation of Lightning-Induced Transient Effects on a Hybrid Photovoltaic–Wind System Based on Lightning Protection Standards

Installing surge protection devices in a hybrid photovoltaic (PV)–wind system is essential to guarantee the survival of the system’s components. If the surge arresters are connected without taking into account the recommendations given by standards, the equipment to be protected might be damaged despite the energy coordination of the arresters. In this study, nonlinear surge protective devices (SPDs) are designed for a multi-MW hybrid system based on lightning protection standards with optimised threat level ratings to investigate the mitigation of lightning transients to an acceptable level. The system is implemented using Power System Computer-Aided Design for Electromagnetic Transients including Direct Current (PSCAD/EMTDC) software. It comprises a 2 MW PV farm, a 2 MW wind farm, and a backup energy storage system (ESS), which are all connected to a 132 kV grid via a step-up transformer and a transmission line. The results were obtained at critical system nodes for two standard lightning current surges, i.e., 1/10 µs and 10/350 µs, considering two lightning strike point scenarios with and without a lightning protection system (LPS). The simulation results showed that the connected SPDs could successfully limit the transient overvoltage in the system to an acceptable level. The analysis in this work is crucial for designing, operating, and maintaining a hybrid PV–wind system. It can help to find the potential vulnerability areas within such a system and implement appropriate protection measures since there is no available lightning standard for such systems. Additionally, it assists the system operators in increasing the uptime and dependability of their RE systems, limiting expensive downtime and environmental effects while optimising energy output. Based on the results obtained, recommendations were made for lightning protection developers.

Development and laboratory testing of a lightning current measurement system for wind turbines

Dimensioning, testing and maintenance of the lightning protection system of wind turbines can be improved using the local distributions of lightning current parameters instead of those on which lightning protection standards rely. This paper presents a prototype system for measuring lightning currents’ waveforms on wind turbines. The prototype is being developed at the Faculty of Electrical Engineering and Computing, University of Zagreb, Croatia. The system's fundamental components are two Rogowski coils and their corresponding integrators. One coil is optimized for lower frequencies and amplitudes, while the other is for higher ones. The cRIO real-time controller is used as an acquisition system, with acquisition logic developed using LabVIEW. The controller has one digitizer for each coil and a GPS synchronization module. The system was tested in the High Voltage Laboratory at University. It was recently installed on an actual wind turbine in Croatia, located in an area characterized by high winter lightning activity. Simultaneously with the prototype measurement system, the lightning activity in the wind turbine micro-location will be monitored by three other systems: the lightning location system, additional lightning monitoring sensors installed in the blades of the same wind turbine and a high-speed camera installed at the wind turbine location.

Tower impulse grounding resistance measurement based on multiple frequency impedance

AbstractTower impulse grounding resistance is important for judging the lightning protection performance of transmission lines. Therefore, it is significant to accurately measure the tower impulse grounding resistance. Existing measurement methods mainly contain the real‐type test method and the impulse coefficient method. However, the real‐type test method requires heavy and complex excitation and measuring equipment, which is difficult to be used in a practical environment. The impulse coefficient method adopts the empirical equations, which could have large measurement errors in different environments. To solve the above problems, this paper studies a novel impulse grounding resistance measurement method (IGRMM) based on multiple frequency impedance. Spectrum characteristics of typical lightning currents and the calculation method of impulse grounding resistance of grounding electrodes are studied, the IGRMM is proposed. Finally, a case study and on‐site tests are carried out. The results show that the proposed IGRMM can accurately obtain the impulse grounding resistance by measuring grounding impedance at a few frequency points, which helps accurate and convenient evaluation of impulse grounding performance in practical environments and lightning protection performance of the power transmission systems.

EFFECT OF DISCHARGE CURRENT MAGNITUDE ON EFFECTIVENESS OF OVERHEAD POWER LINE PROTECTION AGAINST DIRECT LIGHTNING STROKES

In this paper the efficiency of lightning shielding provided by single overhead ground wire mounted atop of a double circuit self-supported 220 kV lattice power transmission line tower with a total height of 37.115 m was examined. According to the electro-geometric concept, each phase conductor of a power transmission line has an area where the overhead ground wire does not provide full protection against a direct lightning strike. The width of this unprotected area depends on the design and dimensions of overhead power line tower, the expected magnitude of the lightning current and decreases with increasing magnitude of the discharge current. The lightning protection effectiveness of upper and middle phase conductors was studied. The values of the minimum lightning current, capable of causing an insulation flashover in case of the lightning shielding failure were calculated. The minimum values ​​of the lightning current at which complete shielding is achieved have also been determined. It was found that for upper phase conductor the minimum current at which a complete lightning shielding is achieved is 7.597 kA, and it is smaller than minimum current of 8.604 kA capable to cause an electrical flashover of the transmission line insulation. For middle phase conductor the lowest current at which a complete lightning shielding is achieved is 5.976 kA, that is much smaller than minimum current of 9.206 kA leading to an insulation flashover. The results show that the specified overhead power line is protected from dangerous lightning currents. However, computations show that downward lightning flashes having a smaller current magnitude are able to bypass the shield wire and hit the phase conductors. In this regard, due to unpredictable nature of lightning, to improve the lightning protection of power lines, other measures can be applied, including the use transmission line arresters mounted on or near towers at individual points of the power line. When thunderstorm activity increases due to global warming, strengthening of lightning protection measures is justified.

Protection Design and Lightning Zone Analysis for Unmanned Aerial Vehicle with Composite Wings

This paper describes the analysis of lightning strike zoning, the indirect lightning data simulation and the protection design for lightning indirect effects of equipment by lightning strike for unmanned aircraft consisting of composite wings. Through the analysis of lightning strike zoning according to the external shape of unmanned aerial vehicles, the structure areas that should be protected during lightning strike is derived, and the protection requirements of lightning indirect effects for flight critical equipments and equipment that must be operated upon lightning strike was derived. Lightning protection levels according to the location of mounting equipment and surrounding structure materials for each equipment was derived, and the protection design of the unmanned aerial vehicle with composite structures was also proposed from direct effect of lightning. Later, the lightning protection technology will be verified by the ground test of lightning direct and indirect effects.

Investigation of lightning attachment characteristics of wind turbine blades with different receptors

Wind power generation system is one of the most important components of new energy power system. However, lightning disasters seriously threaten the safe and stable operation of wind turbine blades. In order to protect wind turbine blades from lightning, different types of lightning receptors are developed. In this paper, lightning discharge experiments of wind turbine blades are carried out to study the lightning protection effects of tip, side, and metal mesh receptors. The lightning discharge processes of wind turbine blades with different receptors are observed and the lightning protection failure rates are recorded. Electric field simulations have been done to analyze the lightning discharge mechanism and discuss the lightning protection optimization methods of wind turbine blades, which can give references for the lightning protection design of wind power generation system.

Development of a Lightning-Induced Overvoltage Suppression Device for the 10 kV Distribution Network

The critical point of lightning protection of the 10 kV distribution network is lightning-induced overvoltage protection. The traditional lightning protection measures cannot solve the problem for the 10 kV Distribution Network. This paper developed a distribution network lightning-induced overvoltage suppression device. The device comprises core inductance, nonlinear resistance, and a parallel adjustable gap. The device operates in three states according to the lightning overvoltage amplitude. The lightning energy is discharged through the device to the earth. The lightning-induced overvoltage amplitude is reduced to below 75 kV. The device’s effectiveness is verified by theoretical analysis and simulation in MATLAB/SIMULINK. The device has significant advantages, such as good lightning protection affection, minor disturbance to the distribution network, and light installation work volume. The device has a good application prospect.

Lightning Protection With a Differentiated Arrester Configuration for Distribution Networks Using a Multi-Objective Optimization Procedure

In addition to insulator flashover, lightning damage of surge arresters (SAs) is also considered in evaluating the lightning performance of a distribution network. This paper presents a novel multi-objective optimization framework for designing differentiated SA protection, by minimizing both the flashover number and SA damage rate. An artificial neural network and an energy-distribution surrogate model are developed for the efficient evaluation of these two targets in an optimization process. The samples for building these models are generated with a hybrid simulation approach together with a Monte Carlo method. It is concluded that the surge energy into an SA generally follows a log-normal probabilistic distribution. The mean of energy absorption decays exponentially with the distance to the stroke location. Differentiated SA configurations for a 10kV distribution network are then identified by balancing the need of minimizing these two targets. It is found that when increasing the SA number, the damage rate becomes dominant and SAs are recommended to be located close to the dead-end poles in sub-feeders. Otherwise, the annual flashover number becomes dominant and SAs tend to be located around the junction poles on the main feeder. When the annual flashover number is primarily addressed, the pole-group selection strategy is the best one due to its simplicity and better performance. However, if both the annual flashover number and damage rate are of concern, the proposed optimization procedure is recommended to achieve a balanced lightning performance

Experimental Evaluation of Lightning Attachment Characteristic of Two Adjacent Wind Turbines

Lightning attachment characteristic of wind turbines have been investigated by experiments with two adjacent 1:100 reduced-scale wind turbine models, simulating two 2-MW wind turbines with blades equipped with two pairs of lightning receptors. Factors including directions of downward lightning leaders relative to the two wind turbine models, and blade rotation angles, were considered. Obtained results show that receptors, especially the blade-tip receptors, have excellent protection effect on the lightning leaders from higher altitudes or from the side of wind turbines, whereas they show weaker protection effect for those from lower altitudes or from the front of wind turbines. Moreover, blade rotation angles of two wind turbines have a certain impact on lightning attachment rates, showing a tendency that the protection effect of wind turbines can be improved with the increase of relative angle difference, the elevation angle difference of uppermost blade of two adjacent wind turbines. The underlying mechanism of this tendency is also discussed. Our experimental results show significance for improving the overall lightning protection capability of multiple wind turbines in wind farms.

Lightning protection technology and grounding technology of transmission tower shared equipment

For the power transmission tower shared equipment, there are strong current wireless interference and complex grounding environment, which leads to problems such as unstable operation of the shared equipment. Based on the multi-grade surge protector and new grounding technology, through the impulse experiments, we apply simulated lightning current generated from combined wave generator (1.2/50 μs, 8/20 μs) on the modle, and an oscilloscope is used to collect residual voltage and current data to calculate the absorbed energy of the grounding unit. It is concluded that when the impulse voltage is between 300 V and 3500 V, as the impulse voltage increases, after passing through the multi-grade surge protector and grounding unit, the residual voltage and current value continue to increase, and the residual voltage value is 23.4 V–29.6 V increases linearly, and the increase is small; the internal resistance of the grounding unit decreases with the increase of the impulse voltage. The energy absorbed by the grounding unit is positively correlated with the impulse voltage and negatively correlated with the internal resistance, and its energy absorption percentage decays linearly. The multi-grade surge protector can effectively clamp the residual voltage value within a safe value, and its discharge effect is better than that of the traditional protection mode. It provides a theoretical basis and data reference for the lightning protection and anti-interference projects of the actual transmission tower sharing equipment, and has certain practical value.

Lightning Protection of Floating Photovoltaic Power Plants—Simulation Analysis of Sample Solutions

Photovoltaic power plants are gaining in popularity and availability every year, resulting in a massive increase in their number and size. However, each such investment involves allocating large land areas, the cost of which may be high. For this reason, there has been an increasing interest in the use of post-industrial wastelands in the form of artificial water reservoirs which often occupy large areas. Because their use as places of recreation can be dangerous for people, it is a cheap alternative for the foundation of a floating photovoltaic power plant. In addition, it has an advantage over the land version in that it is possible to produce a more significant amount of energy by using the sun’s rays reflected from the water’s surface. Despite these undeniable advantages, such a structure poses several technological challenges. This article focuses on the aspect of lightning protection, which is particularly important due to the structure’s location in the open, and also a specific ground type with noticeably different mechanical and electrical characteristics than typical soil. Aspects such as the lightning hazard, arrangement of lightning rods, down conductors, lightning equipotential bonding, and various earthing configurations are discussed. The presented analysis is based on geometric models and simulations made in the Ansys/Maxwell 3D environment and is supplemented with calculations in Matlab/Simulink.

PRINCIPLES OF THE CHOICE OF THE COMBINED LIGHTNING PROTECTION FOR COMPOSITE MATERIALS OF DIELECTRIC POLYMERS

General approaches to solving the problem of lightning protection of composite materials are considered. In particular, the use of dielectric composites, which are radio transparent, requires the organization of their reliable lightning protection, which involves the use of conductors. Thus, the development of segment tires creates the prerequisites for realizing the advantages of knitted combined weaves, including metal threads, and requires further research.