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Overvoltage and Earthing Protection
Published in Ramesh Bansal, Power System Protection in Smart Grid Environment, 2019
N. T. Mbungu, J. J. Justo, Ramesh Bansal
The tropical regions around the earth’s equator are most affected by the highest densities of a thunderstorm with lighting. In some sectors of the world, the storms usually appear in summer. While in some temperate climate zones, even in winter it can be observed that significant thunderstorms can affect the entire power grid by injecting severe overvoltages [12]. The protection of the electrical system against lightning flashover is first designed under bid data structures by using K-nearest neighbour and K-dimension tree in the smart grid environment [13]. The application aims to create real-time monitoring of lightning history so that the protection device can act in an intelligent controlled manner through a K-nearest neighbour search algorithm. In Liu et al. [14], the protection of high voltage (HV) in the smart grid for direct current (DC) is presented. The research aims at the ability of HV equipment to withstand overvoltage due to the lightning event. This chapter focuses on the conventional protection strategy that can be used in the smart grid application, which can protect the electrical grid during overvoltage, earthing and lighting events.
Weather and climate
Published in Howard T. Odum, Elisabeth C. Odum, Mark T. Brown, Environment and Society in Florida, 2018
Howard T. Odum, Elisabeth C. Odum, Mark T. Brown
When an air mass is warm at the bottom and cool at the top, it is unstable and may develop vertical convection (up and down circulation). Up currents are marked by towering cumulus clouds. If there is enough energy, the up currents go up 4 to 6 miles (6.4 to 9.6 km), spreading out at the top with a cloud that looks like the blacksmith’s anvil of days past. When currents in a storm are large enough to develop lightning, the storm is called a thunderstorm.
Lightning Injuries
Published in Leslie A. Geddes, Handbook of Electrical Hazards and Accidents, 1995
Power-line mediated shocks result from a subject being near or in contact with an appliance connected to the power line when it is struck by lightning. Such shocks can vary in severity, depending on how well the subject is in contact with the appliance and ground. Therefore it is prudent to unplug appliances or keep away from them during a thunderstorm.
Lightning fatalities and its correlation with social variables in Northwestern Mexico
Published in Geomatics, Natural Hazards and Risk, 2023
Grisel Alejandra Gutiérrez-Anguamea, Carlos Manuel Minjarez-Sosa, Xochitl Guadalupe Torres-Carrillo, Guadalupe Esteban Vázquez-Becerra
Natural phenomena can be assessed by the effects and damages produced in the physical environment. Thunderstorms are not only one of the most spectacular natural phenomena, but also one of the most destructive and dangerous due to their strength and randomness (Minjarez-Sosa and Waissman 2017; Minjarez-Sosa et al. 2012), producing CG flashes that, some of those strike the ground and some of those do not. CG flashes are classified according to the path and direction of the current that travels in the bright channels associated with each flash. In addition to CG flashes, thunderstorms also produce intracloud or in-cloud (IC) pulses, which are lightning flashes that occur inside the vacuum of a cloud and do not touch the ground or any objects on the earth. Lightning that strikes the ground is referred to as cloud-to-ground (CG) strokes (Cummins and Murphy 2009). CG strokes occur via both a downward-moving process termed as leader and an upward-moving process termed as return stroke (Bava and Rakov 2009); furthermore, the transferred charge from an electrified cloud to the ground can occur in one or more locations in a sequence of individual return strokes with peak currents up to 200 kA (Schonland 1964; Rakov and Uman 2003; Uman and Krinder 1989). CG strokes develop only when the lowest tip of the leader connects with one of the upward streamers emanating from tall, isolated, pointed objects on the ground, such as trees, poles, and sometimes open water; CG strokes can be harmful, causing injuries, fatalities, and economic losses (Holle and Cooper 2016).