Analysis and optimisation of a bearingless induction motor's suspension force and unbalanced magnetic pulling force mathematical model

2020 ◽  
Vol 14 (7) ◽  
pp. 1247-1255
Author(s):  
Zebin Yang ◽  
Qifeng Ding ◽  
Xiaodong Sun ◽  
Qian Zhao ◽  
Jiasheng Luo
Keyword(s):  
Mathematical Model ◽  
Pulling Force

scholarly journals A Full-Period Mathematical Model for a Hybrid-Rotor Bearingless Switched Reluctance Motor

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2383
Author(s):  
Zeyuan Liu ◽  
Mei Chen ◽  
Yan Yang ◽  
Chengzi Liu ◽  
Hui Gao
Keyword(s):  
Mathematical Model ◽  
Switched Reluctance Motor ◽  
Radial Force ◽  
Magnetic Bearing ◽  
Stable Operation ◽  
Switched Reluctance ◽  
Reluctance Motor ◽  
Full Period ◽  
Pulling Force ◽  
Straight Lines

A bearingless switched reluctance motor (BSRM) has the combined characteristics of a switched reluctance motor (SRM) and a magnetic bearing. The hybrid-rotor BSRM (HBSRM) discussed in the paper has a twelve-pole stator and an eight-pole hybrid rotor, which is composed of a cylindrical rotor and a salient-pole rotor. Although the asymmetry of the hybrid rotor makes the structure and magnetic field of the HBSRM more complex, it can always produce a significant amount of magnetic pulling force to levitate a rotor shaft at all the rotor angular positions of each phase, which is not available in a traditional BSRM. The classical mathematical model for a conventional BSRM is valid only when its rotor rotates from the start of the overlap position to the aligned position, and the radial force and torque derived from this model are discontinuous at the aligned positon, which is harmful to the motor’s stable operation. In this paper, a full-period mathematical model on the assumption that the gap permeance is cut apart by straight lines or improved elliptical lines for a 12/8-pole HBSRM is provided. On the basis of this mathematical model, the continuity of the radial force and torque at all the rotor angular positions can be guaranteed, and the fine characteristics of this mathematical model have been verified by simulations.

The algorithm for determining the pulling force while dragging a pipeline

2018 ◽  
Vol 13 (3) ◽  
pp. 36-41
Author(s):  
I.N Krioni ◽  
A.V. Semenova ◽  
V.N. Kireev
Keyword(s):  
Mathematical Model ◽  
Drag Force ◽  
Drilling Fluid ◽  
Tractive Effort ◽  
Frictional Forces ◽  
Pulling Force

This article describes the process of dragging a pipeline through a channel. In the simulation of this process, the interactions between the pipeline, the drill rod, the soil and the bentonite mud are taken into account. Dragging of the pipeline through the well is hampered by frictional forces of the pipeline and the drill rod against the soil, as well as the drag force of the pipeline when it moves in the drilling fluid. In the construction of a mathematical model, the influence of these forces is taken into account. To determine the frictional forces, the pipeline and the drill rod were considered as a flexible non-stretch filament. An algorithm for determining the tractive effort is created and implemented. A separate stage of the work is devoted to the accounting of ballasting of the pipeline.

Mathematical model of hit phenomena and its application to movie advertisement

2008 ◽  
Author(s):  
Ishii Akira ◽  
Yoshida Narihiko ◽  
Hayashi Takafumi ◽  
Umemura Sanae ◽  
Nakagawa Takeshi
Keyword(s):  
Mathematical Model

Imprecision of Laboratory Determinations and Diagnostic Accuracy: Theoretical Considerations

1974 ◽  
Vol 13 (03) ◽  
pp. 151-158 ◽  
Author(s):  
D. A. B. Lindbebo ◽  
Fr. R. Watson
Keyword(s):  
Mathematical Model ◽  
Diagnostic Accuracy ◽  
Diagnostic Process ◽  
Clinical Laboratories ◽  
Non Linear ◽  
Theoretical Considerations ◽  
Made In

Recent studies suggest the determinations of clinical laboratories must be made more precise than at present. This paper presents a means of examining benefits of improvement in precision. To do this we use a mathematical model of the effect upon the diagnostic process of imprecision in measurements and the influence upon these two of Importance of Diagnosis and Prevalence of Disease. The interaction of these effects is grossly non-linear. There is therefore no proper intuitive answer to questions involving these matters. The effects can always, however, be calculated.Including a great many assumptions the modeling suggests that improvements in precision of any determination ought probably to be made in hospital rather than screening laboratories, unless Importance of Diagnosis is extremely high.

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