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Overvoltages and Insulation Requirements
Published in Amitava Sil, Saikat Maity, Industrial Power Systems, 2022
Lightning is an electrical discharge between cloud and the earth, between clouds or between the charge centers of the same cloud. There are two main ways in which the lightning may strike the power system. They are (i) Direct stroke and (ii) Indirect stroke. In direct stroke, the lightning discharge is directly from the cloud to an overhead line. From the line, current path may be over the insulators down to the pole to the ground. The overvoltage set up due to the stroke may be large enough to flashover this path directly to the ground. The direct stroke can be of two types: (i) Stroke A, where the lightning discharge is from the cloud to the subject equipment (e.g., overhead lines). The cloud will induce a charge of opposite sign on the tall object. When the potential between the cloud and line exceeds the breakdown value of air, the lightning discharge occurs between the cloud and the line. (ii) Stroke B, where the lightning discharge occurs on the overhead line as a result of stroke A between the clouds.
Quantum Quagmire: Dead End for Energy Miracles
Published in H. B. Glushakow, Energy Miracles, 2022
Lightning is another example of well-defined variations in the speed of light. Lightning discharges contain the entire spectrum of electromagnetic radiation (from shockwaves, to visible light, to X-rays and gamma rays) and has been many times measured to travel one-third to one-half the speed of light. Even more telling is that the luminous continuously propagating sections of a lightning strike, called Dart Leaders, have been measured with high-speed cameras to travel only one-thirtieth the speed of light.79 Which simply means that light speed varies as a function of both the type of light and the interference of the medium or mediums through which it travels.
Guard against sudden static discharge
Published in Michael Wiklund, Kimmy Ansems, Rachel Aronchick, Cory Costantino, Alix Dorfman, Brenda van Geel, Jonathan Kendler, Valerie Ng, Ruben Post, Jon Tilliss, Designing for Safe Use, 2019
Michael Wiklund, Kimmy Ansems, Rachel Aronchick, Cory Costantino, Alix Dorfman, Brenda van Geel, Jonathan Kendler, Valerie Ng, Ruben Post, Jon Tilliss
The ultimate static discharge is a lightning bolt. People can protect their homes with lighting rods that redirect the energy from a lightning strike to the ground. Homeowners can also protect equipment that might catch fire by installing surge protection devices. And, people can protect themselves by knowing when to get indoors with the help of advanced warning from lightning detection devices that sense the electromagnetic emissions from lightning bolts.
Modeling the change in electric potential due to lightning in one-dimensional space
Published in Applicable Analysis, 2022
Lightning is a process in which the electric charge buildup in two charge centers increase and eventually reach a breakdown threshold, leading to a lightning discharge. This forms a lightning channel, it is what we see as the lightning. During this process the conductivity along the lightning channel becomes very large, therefore causing a change in the electric potential as well. In this study, we obtain a formula for the change in the electric potential immediately after lighting in a one-dimensional space. To this end, we solve the following system:
Predicting the Class of Salt Contamination for Wind Turbine Blade under a Lightning Strike Using Fuzzy Inference System and Probabilistic Neural Network
Published in Electric Power Components and Systems, 2023
Shenglu Huang, Jiannfuh Chen, Mingshou Su, Chienyi Chen
Wind power is an important source of power generation capacity and the global cumulative wind power capacity in 2020 is approaching 743 GW (707 GW onshore and 35 GW offshore) [1]. Wind turbines (WTs) are usually located in regions with frequent thunderstorm activity and high salt deposit density. A blade may fall or be destroyed when the blades of a WT are struck by lightning. Lightning may produce surge currents causing a catastrophic failure of the control and electrical systems. Salts in polluted fog also increase pollution of the WT and result in insulation breakdown or flashover. As wind energy finds increasing use for electric power systems, WT blades must be monitored for lightning damage and salt contamination.
A failure prediction method of power distribution network based on PSO and XGBoost
Published in Australian Journal of Electrical and Electronics Engineering, 2022
Jian Fang, Hongbin Wang, Fan Yang, Kuang Yin, Xiang Lin, Min Zhang
In windy weather, it is easy for power distribution networks to contact surrounding trees or be hooked by foreign matters so as to cause single-phase ground failure. In continuous rainy days, the increase in humidity may affect the insulation performance of the equipment, leading to leakage of current or pollution flashover. Under the action of thunder and lightning, power distribution network-related equipment may suffer overvoltage, current leakage or other failures due to lightning stroke. Therefore, this paper mainly selects weather indexes including gale, precipitation, thunder and lightning as the input of the failure risk prediction model, as shown in Table 2.