NDLI: Modelling of Magnetic Pull in Large Size Generator

Content Provider	The American Society of Mechanical Engineers (ASME) Digital Collection
Author	Pennacchi, Paolo Frosini, Lucia
Copyright Year	2005
Abstract	This paper presents a method to analyze the dynamical behaviour of large size generators due to the magnetic pull. In rotating electrical machines, the electromagnetic radial forces acting upon rotor and stator surfaces are very large, but they are balanced when the rotor is concentric with the stator. Similarly, the tangential forces produce only an axially rotating moment. If the rotor becomes eccentric, then an imbalance of these forces occurs, so that a net radial electromagnetic force, known as Unbalanced Magnetic Pull (UMP), is developed. The models traditionally proposed in the literature to study the UMP can be considered as reliable in case of small size electrical machines supported by rolling bearings. On the contrary, in case of large size machines, such as turbo-generators supported by oil-film bearings, the approximation of circular orbits of the rotor is not acceptable. Nevertheless, the authors who have dealt with UMP in big size generators have disregarded that these rotor filtered orbits are elliptical and generally the orbit centres are not concentric with the stator. In order to provide a more realistic model and an original contribution, in this work the actual distribution of the air-gap length during the rotation will be determined in analytical terms, by taking into account the effects produced by the actual rotor orbit. The actual UMP is calculated by using the air-gap permeance approach and the simulation of the dynamical behaviour of a 320 MW generator is presented, showing the harmonic content of the UMP and the presence of non-linearities.
Sponsorship	Design Engineering Division and Computers and Information in Engineering Division
Starting Page	1191
Ending Page	1200
Page Count	10
File Format	PDF
ISBN	0791847381
DOI	10.1115/DETC2005-85368
e-ISBN	0791837661
Volume Number	Volume 1: 20th Biennial Conference on Mechanical Vibration and Noise, Parts A, B, and C
Conference Proceedings	ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference
Language	English
Publisher Date	2005-09-24
Publisher Place	Long Beach, California, USA
Access Restriction	Subscribed
Subject Keyword	Rotor dynamics Non-linearity Unbalanced magnetic pull Generator Modeling Generators
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in