|Author:||Ng, Kin Chiu|
|Title:||Magnetic field shielding for transformer room|
|Subject:||Hong Kong Polytechnic University -- Dissertations|
Electromagnetic fields -- Health aspects
Buildings -- Health aspects
|Department:||Department of Building Services Engineering|
|Pages:||pages : color illustrations|
|Abstract:||This thesis focuses on magnetic field shielding for transformer room in buildings. A rapid development of engineering technology is growing day by day. The advancement of building services engineering makes buildings more and more suitable for human activities. As more and more systems are installed to maintain a standard of indoor environment, the demand of electrical energy is also growing continuously. The great demand of electricity not only brings us a better indoor environment, it also brings an impacts on public health and electrical equipment. Electromagnetic fields often comes with high electricity application. The existence of electromagnetic field grabs a big attention on problems of magnetic fields and the measures of magnetic field shielding. This thesis, therefore, mainly investigate the magnetic field shielding in transformer room, which is one of the largest magnetic field source in a building. Shielding material used in this thesis is galvanized iron plates. Ventilation ducts and gaps are a common structure to be observed in a transformer room. Other common arrangement of transformer in transformer room is the location and orientation of transformer. A mass literature review on magnetic field shielding was conducted to familiarize and understand the scale of studies that carried out by other researchers. A various conditions experiments were conducted to realize the influence of different configuration of transformer and transformer room to performance of magnetic field shielding. After the completion of experiments, this thesis would display the performance of magnetic field shielding and the measurements of detected magnetic field strength among various conditions. A comparison was also made to figure out the requirement for effective magnetic field shielding. With different conditions, such as the orientation of source-to-test point, measurement location and installation of ventilation duct, considered in the experiments, change of configuration can either significantly affect or slightly alter the performance of magnetic field shielding. The largest degree of mitigation of magnetic field shielding is approximately 40 - 50%. The thickness of galvanized iron plates is 1.5 mm (rest of the sides) and 2.0 mm (two walls).|
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|991022168751703411.pdf||For PolyU Staff & Students||3.12 MB||Adobe PDF||View/Open|
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