Myths, Safety and Awareness of Lightning Protection in Bangladesh
Md Rosaidul Mawla,
Nasrin Sultana,
MSAAF Shiblee Shiblee
Issue:
Volume 6, Issue 2, December 2020
Pages:
7-13
Received:
30 July 2020
Accepted:
17 August 2020
Published:
4 November 2020
Abstract: Bangladesh, being a tropical country, experiences relatively high density of lightning each year. Lightning has been identified as one the major causes of weather-related deaths and injuries in Bangladesh. The government of Bangladesh has declared lightning as natural disaster when 81 people have lost their lives in just two days due to lightning in 2016. Lightning is a source of fearfulness, inquisitiveness, inspiration and panic. As number of death has increased in Bangladesh in lightning, so the safety rules for the installation of lightning prevention system which is a mandatory provision under Bangladesh National Building Code, to be followed for building construction. People of low literacy rate have the tendency to violate more, the basic lightning safety guidelines. Hence, awareness program has started to educate the people especially the rural one. However, a survey has been conducted to find out the common myths, beliefs, misconceptions in Bangladesh and its impact on lightning safety. It summarizes the prevailing lightning safety awareness and education around the world. Finally, it puts forward some ray of light about the suggestions about lightning protection, safety and awareness for Bangladeshi people to curb the myths and misconceptions.
Abstract: Bangladesh, being a tropical country, experiences relatively high density of lightning each year. Lightning has been identified as one the major causes of weather-related deaths and injuries in Bangladesh. The government of Bangladesh has declared lightning as natural disaster when 81 people have lost their lives in just two days due to lightning i...
Show More
Analysis on Electromagnetic Force Properties of End Windings in Turbo-Generators
Guiji Tang,
Hongchun Jiang,
Yuling He,
Gaurang Vakil
Issue:
Volume 6, Issue 2, December 2020
Pages:
14-21
Received:
14 December 2020
Accepted:
25 December 2020
Published:
31 December 2020
Abstract: Electromagnetic forces on the end windings will stimulate intensive vibrations and cause insulation wearing, and the vibration wear will further induce the coil short circuit. Eventually accidents and losses will be brought. Therefore, it is of great significance to study the electromagnetic force properties of end windings. This paper studied on the electromagnetic force properties of end windings in turbo-generators. Firstly, the magnetic field in the end region was analyzed by winding MMF superposition principle and air gap magnetic conductivity method, and the electromagnetic force is got with Ampere law. Then, taking QFSN-600-2YHG turbo-generator as study object, the 3 directional electromagnetic forces and the mechanical responses on the end windings were calculate by electromagnetic-structure coupling finite element analysis method. Finally, the experiment vibrations are tested, and the acceleration data was compared with simulated result. It is shown that each directional electromagnetic force contains both the DC component and even harmonics, which will result in the winding vibration mainly at the double fundamental frequency. Meantime, the radial acceleration is the largest and the axial one is the least, so the radial vibration should be paid more attention to in daily monitoring. Moreover, the max deformation mainly occurs on the nose and middle part of the involute, and these locations should be strengthened in design and manufacture.
Abstract: Electromagnetic forces on the end windings will stimulate intensive vibrations and cause insulation wearing, and the vibration wear will further induce the coil short circuit. Eventually accidents and losses will be brought. Therefore, it is of great significance to study the electromagnetic force properties of end windings. This paper studied on t...
Show More
