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In electrical protection, there is a method of electrical protection of buildings against atmospheric discharges called the electro-geometric method or the rolling sphere method. So far, it is possible to achieve the implementation of this method graphically, that is, representing through plans and technical drawings, the protection conditions of the analyzed structure and obtaining from these graphic representations the protection parameters with the consequent errors caused by the scales and dimensions of the work plane. In the present work, a mathematical model is obtained that allows, using specific calculations, to analyze the dynamic behavior of a protection system against atmospheric discharges without worrying about the limitations given by the scales and planes. The set of equations obtained in the model allows us to determine the different parameters that define the protection system against atmospheric discharges (lightning) without depending on the graphical representation of the system's topology. This is an open access article under the CC BY-SA license.
In this work, an analysis of the quality of electrical energy is carried out, based on the replacement of High-Pressure Sodium Vapor Lamps (HPSV) with Light Emission Diode (LED) lamps in the low voltage networks of public lighting. The study takes into account the advantages and disadvantages of using this technology, among the efforts to reduce electricity consumption and achieve higher rates of electro-energy efficiency. The effect of current harmonics on transformation losses, line losses, and voltage profiles in the circuit is analyzed. Flow runs in the public lighting circuit are obtained from models developed in MATLAB. The models of the loads with harmonic content for the simulation of the lamps were developed from measurements made in the laboratory for these loads. The results obtained due to the replacement of HPSV lamps by LEDs did not show significant differences in terms of harmonic contamination, determining that both technologies present harmonic distortion rates of currents above the standard value. Besides, a significant reduction in the voltage drop and power losses of the lines is achieved, improving the power factor in the distribution network.
Lightning is one of the inevitable disastrous phenomena which in addition to damaging tall edifices, might also consequently endanger humans due to lightning-human interactions. This research focuses on analyzing lightning hazards to humans in the vicinity of heritage monuments in India and Sri Lanka. Five monuments which include three giant stupas namely Ruwanweliseya, Jethawanaramaya and Abayagiriya from Sri Lanka and two large temples namely Brihadishvara Temple and Gangaikonda Cholapuram from India have been chosen for investigation. Lightning-human interaction mechanisms namely direct strike, side flash, aborted upward leader, step and touch voltages have been investigated for the most onerous scenario on humans in the vicinity of the monuments. Firstly, the electro-geometric model as stipulated in standards has been implemented to ascertain the effectiveness of lightning protection to the structures. Subsequently, the study has been extended to the computation of step and touch voltages utilizing lightning current and electrostatic models based on Finite Element Method (FEM) using COMSOL Multi-physics®. Detailed plots of electric field and voltage distribution of lightning on humans due to a typical lightning current of 30 kA have been obtained. The final study involves assessment of current through humans which is estimated based on lumped R-C human model representation using OrCAD Cadence®. The analyses reveal that humans are invariably shielded against direct strikes whereas effects due to side flashes are minimal. During strikes to the monuments, high voltage may appear due to step and touch potential under dry conditions, though such effects could be mitigated by appropriate earthing system.
This research aims to evaluate the trends in the publication of papers on issues related to power circuit breakers, aimed at the technologies implemented, as well as those countries with higher level of publications, making a comparison between authors, research institutes, and a description of the last 10 years with more publications. All the information found in this report is compiled in bibliographic databases such as books of substation designs and research papers with a focus on electrical protection equipment and emphasis on high voltage switching devices. A technology research is conducted over the last ten years to analyze the state of the art of high voltage operating elements with respect to new technologies.
This paper presents a developed logical tripping scheme to improve conventional protection performance. Adaptive single pole auto reclosure (ASPAR) system is proposed that considers, automatically tripping and reclosing of a multi-shot independent pole technique of a circuit breaker at a predetermined sequence, which can be used to boost the synchronization of the power grid under the transient fault conditions. Moreover, the ASPAR can be utilized to enhance the electrical system stability and reliability at the same operating conditions. Based on the three-phase system, the Artificial neural network (ANN) in this work has been done in order to diagnose and detect healthy and faulted phases. The proposed ANN fault classifier method consists of the logic gates, router circuits, timers, and positive and negative sequence analyses circuit. In addition, it is used to give the ability to recognize a fault type, which by training on the sequence angle values and coordination of the transmission line. Three-phase overhead transmission line including the proposed ASPAR is built in MATLA \SIMULINK environment. Thus the performance ANN-fault classified is tested under different fault conditions. Simulation results show that the proposed ASPAR based on ANN is accurate and well performance. Whereas resultant tripping and reclosing signals of ASPAR are successfully provided that enhances the circuit breaker mechanism under these operating condition.
In this work a system is designed and implemented in SCADA MOVICON 11.5, in which the operation of five seawater desalination lines by reverse osmosis which work in parallel, with four coastal wells and two end-of-line pumps of the permeated water obtained are integrated, synchronized and supervised as a single plant. Each desalination line has its own control system and can operate independently. As a product, synchronization algorithms were obtained that were added to the system through script codes, which guarantee continuous productivity in the desalination process, achieving synchronization between the mentioned sub-processes. Simultaneous operations of starting, washing and stopping that affected the performance of the osmosis lines are avoided. Alarms are generated, reports are created, historical records and trends for the decision making on failures prediction, predictive maintenance and troubleshooting.
This paper presents a new approach for determining
the impact of lightning strikes on transmission network elements
failures based on fuzzy logic (FL) and expert systems. The
location of lightning strike is determined by means of system
for lightning location (SLL) and failures in the transmission
network, sorted by type of the equipment, are obtained from
supervisory control and data acquisition (SCADA) system. Two
input datasets include two sets. The first set consists of lightning
strike locations and currents values between the cloud and the
ground. The second set consists of current values from SCADA
system before and after the fault, protection tripping information,
and the switches state and position. The Proposed FL-based
solution based on a fuzzy decision making system (DMS), includes
both data sets in order to provide a power system operator (PSO)
with precise and accurate decision needed in time of emergency.
The described model has been tested for functionality and
correct results have been obtained and thus, confirm membership
function (MF) assessment and proves efficiency and authenticity
of the DMS.
This article proposes a control of lighting and electrical loads, suitable for smart homes, using embedded systems with low-cost wireless communication modules. The system is based on a distributed intelligent home automation architecture, to work autonomously or interconnect wirelessly to a larger system. It has a set of sensors that allow you to ration the use of electricity through automatic switching off the lights or electrical devices, allowing the lighting to be regulated. It has several modules that communicate to a central node wirelessly, and an interface based on a mobile application. UML and Petri Nets were used for the projection, modelling and validation of the system, its implementation was developed in C/C ++ language for 32-bit microcontrollers. Tests of the prototype showed stable behavior, fast communications and sufficient coverage for a single-family house, whose performance is higher to other similar works found in the scientific community.
In this paper, a new active dynamic lightning protection method is proposed based on the large data characteristics of electric power. This method mainly includes two parts: Part one, Neo4j framework model which is used to analyze large data of power system and dynamic regulation of power system, and Python software which is used to compare and analyze different framework models; Part two, the comparison between dynamic lightning and conventional protection methods. The results show that Neo4j traversal speed is 87.5% and 89.1% faster than Hadoop and Spark respectively, clustering effect is 12.5% and 17.8% higher than Hadoop and Spark respectively. As a result, Neo4j framework model is more suitable for the characteristics of large data in power system. After the lightning accident, the power-off time of dynamic lightning protection system is reduced by about 53.1%, and the recovery time of the system also decreased by about 42.8%. In the dynamic regulation of power system, the output of power supply is reduced by 35.1 MW and the load is cut out by 15.8 MW, which greatly reduce the impact of lightning strike on power supply and important load.
- In order to model and visualize the performance of lightning and its protection system, several analytical methods such as the rolling sphere method (RSM) have been developed in which protected and unprotected areas are separated. However, in none of these methods, the scale and severity of the damage can be quantified numerically. In this paper, by using the leader progression model (LPM) in 3D space along with an intelligent algorithm named Teaching-Learning-Based optimization (TLBO), a new method is proposed to identify the vulnerable areas with the highest probability of lightning strikes. In using the TLBO algorithm, a new method for determining the critical range of current is defined and the most vulnerable points on the structure are determined, so that, based on the simulation results, the best positions of the lightning rods can be specified respectively. A sample asymmetric structure of height less than 60 meters is analyzed as a case study, and the optimal locations and heights of lightning rods are determined using the rolling sphere method and the proposed method, respectively. The simulation results validate the effectiveness of the proposed method which makes it suitable for other complex structures.
A 3-D Monte Carlo-type random walk model was constructed for the assessment of lightning attachment probabilities to small structures. The simulation assumed buildings had a negligible impact on the propagation of lightning. A purely stochastic propagation model based on a previously proposed gas and charged particle diffusion process was employed. The attachment was based on the electrogeometric model in which striking distance is determined by return stroke peak current. This model allows for hundreds of thousands of samples to be evaluated in the window of a few minutes on readily available consumer computing hardware. Using this model, it became possible to enable characterizing building protection as a probability distribution of striking distance. Such was done to provide a deeper understanding of the impact of building protection design choices than is readily available from binary testing. The model was calibrated for minimum input resolution, which is found to be insensitive to variations in step length and moderately insensitive to variations in propagation angle distribution, resulting in normalized errors of less than 15% (rms). A parametric sweep of geometric features was performed for a large (100 m x 50 m) rectangular building with catenary wire protection. For heights of less than 30 m, lightning was found to bypass protection structures and strike to the building itself at rates that were insensitive to variations in building height. The extent to which the protection may be recessed from the building's perimeter was found to have a significant impact. Variations in building aspect ratio were found to be of limited impact except for cases of extreme aspect ratio where competition with the ground appears to have resulted in much better lightning protection performance.
Following a series of rocket-and-wire triggered lightning tests with different lightning protection systems carried out at the Camp Blanding, Florida, the experimental studies of impulse current distribution in a lightning protection system of a residential building were conducted in Huta Poreby, located in the southeastern part of Poland, where the soil resistivity is about 40× lower. The obtained and previously published results focused mainly on comparing the effectiveness of different grounding systems of the test house. In this article, the entire system installed in Huta Poreby is modeled and current distribution is analyzed, including the MV/LV transformer and the 500 m long unenergized distribution power line matched at its end. The application of the current generator model instead of a typical impulse source with an arbitrarily defined input current enabled investigating the influence of soil parameters on the obtained current waveforms. With the increase of soil resistivity, the current waveforms become more and more similar to those measured at Camp Blanding, Florida, where soil resistivity reaches 4000 Ωm.
In this paper, a new approach for designing groudging grid is proposed. The design is based on constracting an auxiliary annular grounding grid and transforming the lingtning rod’s grounding poing from main grounding grid to auxiliary grounding grid. Modal analysis and softwave simulataes is employed to obtain the transformed lightning current (and the voltage) and the reduced ressitance. The dual port model is used to calculate the impedance value of the grounding grid. The calculation results of the model are compared with the standard grounding body model EMF. At the same time, the relationship between the induced voltage of each point of the grounding grid and the distance of the lightning current injection point is studied by using the dual port model. The reduced resistance is simulated by building annular grounging grid model and square grounging grid model and making a comparison in performance betwen them. Farther, when there is a lingtning event, instead of providing a low impedance path by the main grounding grid, the design provide anther path by the auxilary grounding grid, which can transfer the lightning current into the auxilary grounding grid. All the model analysis and simulation results are presented and discussed in the paper.
This study elucidates the damage characteristics, microstructure response, and temperature rise of steel alloy Q235B suffered from lightning currents, which is the basis for lightning protection of oil tanks. Damage is inflicted in the designed Q235B specimens by using the Multi-Waveform Multi-Pulse Impulse Current Generator to characterize the damage response induced by four typical lightning current components. The changes in element composition and micro-hardness of Q235B are documented in the experiment. The microstructure changes in response to the temperature rise are analyzed by the proposed lightning-metal temperature rise model. Results reveal that first return stroke current with amplitude of 201.2 kA leads to the largest damaged area of 3523.8 mm2. Continuing current in the stroke intervals with charge transfer of 12.1 C results in the damaged area 12.6 mm2 and depth 0.5 mm. Long continuing current after stroke with charge transfer of 210.1 C leads to the deepest damaged depth of 3.0 mm. The demixing phenomenon occurs on the cross-section, forming the damage zone, transition zone, and origin zone. The damage zone mainly consists of Martensite transferred from Pearlite and Ferrite at temperature 990 °C. The transition zone is mainly Martensite and Ferrite forming at temperature 900 °C. The hardness of the three zones is 450, 310, and 180, respectively. The damaged depth is only 0.001 mm caused by the subsequent return stroke current with amplitude 102.2 kA.
In his paper, "On the Space Protected by a Lightning Conductor" published in Philosophical Magazine and Journal of Science in 1880, William Henry Preece , an influential British general post office electrical engineer, provided a practical method for establishing a zone of lightning protection for structures and buildings. His motivation was to establish methods for protecting the wires on telegraph poles from lightning strikes.
When designing Lightning Protection Systems (LPS), the effectiveness of an air termination structure(s) may be assessed by using the rolling sphere method. This method is outlined in standards BS6651:1999, IEC 62305, and IEEE 998-1996. A number of 2D methodologies are presented in these standards illustrating how to apply the rolling sphere method. This paper proposes a new 3D approach to the application of the rolling sphere method. This new approach analyses the designated air termination structures and forms stationary shapes around the air terminations. This approach focuses on where a rolling sphere can not go rather than where it can go. For example, a concave cone, as shown in Figure 1, will describe the protected area provided by a single lightning mast. Different shapes are required depending on the nature of the air termination system. All shapes will be a combination of sections of concave cones, spheres and cylinders.
Level, Class, and Prospected Safety Performance of a Lightning Protection System for a Complex of Structures (LPCS)
G. Parise, L. Martirano, and M. Lucheroni, "Level, Class, and Prospected Safety Performance of a Lightning Protection System
for a Complex of Structures (LPCS)," in IEEE Transactions on Industry Applications, vol. 46, no. 5, pp. 2106-2110, Sept.-Oct.
2010, doi: 10.1109/TIA.2010.2059370.
Physical damage to structures and threats to life
Protection against Lightning, Part 3: Physical damage to structures and threats to life, NTC 4552-3, Icontec 2008. [Online].