Transient Ground Potential Rise Impact on Reliability of Sensor and IED

Author(s):  
Longlong Li ◽  
Wenbing Zhu ◽  
Zhixin Gao ◽  
Feng Yi ◽  
Wei Xu
Keyword(s):  
Author(s):  
George Christov ◽  
Bolivar J. Lloyd

A new high intensity grid cap has been designed for the RCA-EMU-3 electron microscope. Various parameters of the new grid cap were investigated to determine its characteristics. The increase in illumination produced provides ease of focusing on the fluorescent screen at magnifications from 1500 to 50,000 times using an accelerating voltage of 50 KV.The EMU-3 type electron gun assembly consists of a V-shaped tungsten filament for a cathode with a thin metal threaded cathode shield and an anode with a central aperture to permit the beam to course the length of the column. The cathode shield is negatively biased at a potential of several hundred volts with respect to the filament. The electron beam is formed by electrons emitted from the tip of the filament which pass through an aperture of 0.1 inch diameter in the cap and then it is accelerated by the negative high voltage through a 0.625 inch diameter aperture in the anode which is at ground potential.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4118
Author(s):  
I Made Yulistya Negara ◽  
Daniar Fahmi ◽  
Dimas Anton Asfani ◽  
IGN Satriyadi Hernanda ◽  
Rendi Bagus Pratama ◽  
...  

In this study, the lightning protection system and grounding system of one plant of the petrochemical industry were investigated, evaluated, and improved. The methods used in this study were rolling sphere and angle protection methods. The grounding system of the building under study was modeled and simulated using ATP/EMTP (Alternative Transient Program/Electromagnetic Transient Program) software. The results show that the external lightning protection system of the prilling tower studied does not adhere to IEC 62305 and IEC 1024-1-1 standards. Moreover, the grounding configuration of the DCS building was not appropriate for protecting sensitive equipment inside. Lightning causes an enormous potential difference between lightning ground rods in the grounding system. Additionally, disabling the existing surge protective device (SPD) causes an increase in the magnitude of Ground Potential Rise at the DCS building. Improvement of the lightning protection system of the prilling tower and DCS building on Plant 1 of this petrochemical company as well as some other recommendations for improvements are proposed. This paper also shows evidence that external lightning protection, internal lightning protection, and the grounding system need to be connected to make an exemplary lightning protection system.


2017 ◽  
Vol 2017 (13) ◽  
pp. 2555-2558
Author(s):  
Taiyu Chen ◽  
Hongshun Liu ◽  
Dongyang Hu ◽  
Xinghua Liu ◽  
Tianxi Xu ◽  
...  

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