A lightning strike is considered one of the most risky natural phenomena that can lead to human harmful and the surrounding soil layers. To tackle this issue, this article investigates the influence of direct lightnin...
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A lightning strike is considered one of the most risky natural phenomena that can lead to human harmful and the surrounding soil layers. To tackle this issue, this article investigates the influence of direct lightning characteristics in terms of human body safety. Specifically, such investigation is carried out on the effect of resistivities of two-layer soils on human safety when lightning stroke hits the towers of the high voltage transmission lines (HVTLs). The merit of the proposed study is that the soil ionization phenomenon is taken into consideration. Further, the study focuses on the current passing through the human heart, when step and touch (contact) voltages are generated by grounding potential rise, caused by direct lightning strikes transmission tower and the produced potential rise that a person could be exposed. Also, studying the effects of peak current and time of lightning strokes are investigated. Additionally, the paper presents the effect of different reflection factors on human safety. For validation purposes, the atp program is used in the simulation of the grounding system as well as the human body model. Numerous simulations were accomplished in order to examine the behavior of the current passing through with the human heart. Based on the simulation results, it was concluded that the soil characteristics have superior influences on the contact and step potentials and, accordingly, the survival threshold.
Ferroresonance is a phenomenon that occurs in low loss transformers under certain conditions. Recent developments have led to the introduction of amorphous core materials in distribution transformers to reduce the no-...
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ISBN:
(纸本)9781665403450
Ferroresonance is a phenomenon that occurs in low loss transformers under certain conditions. Recent developments have led to the introduction of amorphous core materials in distribution transformers to reduce the no-load losses that, in turn, have led to an increase in the occurrence of ferroresonance. In this article, the effects of the ferroresonance phenomenon on low loss distribution transformers are investigated. The simulation model was performed via atpEMTP and the overvoltage of ferroresonance triggered by single phase-to -earth and two-phase in the system was simulated and analysed. Also, the critical cable lengths for the incidence of the phenomenon of ferroresonance are determined.
A new experimental rig is presented, developed to design, integrate, verify and validate the control system of the all-new advanced turboprop engine, produced by GE Aviation and chosen by Textron Aviation to power its...
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ISBN:
(纸本)9781785617546;9781785617539
A new experimental rig is presented, developed to design, integrate, verify and validate the control system of the all-new advanced turboprop engine, produced by GE Aviation and chosen by Textron Aviation to power its new Cessna Denali airplane. The atp Wet Rig has been conceived to demonstrate the successful integration of engine components, to perform a functional verification at software and system level and to allow an early validation of the final engine system in a controlled and safe environment, preliminary to flight test activities. A dedicated Engine Simulator has been developed to run the atp Engine model within a Hard Real Time framework. It provides aircraft's interfaces emulation, controls the load actuators and the electrical motors' speeds, replicates consistent loads on the components in compliance with the engine simulated status, intercepts all the EECU electrical I/O lines through appropriate "break out boxes" and physical test points, required for integration purposes. Finally, a dedicated Rig Control System has been developed to communicate and to control all the equipment present in the Wet Rig. It is a distributed system responsible for supervision, test point management, data acquisition, sub-systems control, safety and equipment management, communication with the Engine Simulator.
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