air spindles are one of the main elements of precise machine tools. vibration of these spindles is one of the vital issues necessary for investigation. among parameters which influence air spindle vibrations are rotational speed, compression air method, input nozzle diameter, air gap pressure. in this study using ansys, the effects of air gap thickness on air spindle vibrations have been invest...

Abstract Partially superconducting direct-drive wind turbine generators with high-temperature excitation winding enable an increase of the rated unit power, higher efficiency, and a high, adjustable power factor. The high ampere-turns allow for iron topologies that differ from conventional permanent magnet-excited generators. This study compares four different $$7\,\mathrm{MW}$$ <mml:math xmlns...

For line start permanent magnet synchronous machines (LSPMSMs), the eddy current loss in the rotor, which has of significant effects on rotor working temperature, may cause thermal demagnetization to permanent magnet. Therefore, this paper addresses an investigation on the temperature distribution in LSPMSM based on a 6 kV, 315 kW prototype with solid starting cage bar. Firstly, the loss distri...

A new squirrel-cage rotor structure induction motor (IM) that has a auxiliary permanent magnet (PM) rotor and improved cage-rotor structure is presented to enhance the inherent power factor of the IM, and a prototype motor is fabricated by modifying the rotor of a conventional three-phase four-pole squirrel-cage induction motor. The flux linkage, flux distribution, power factor, core loss and e...

Harmonic vibrations of high-speed rotors in momentum exchange devices are primary disturbances for attitude control of spacecraft. Active magnetic bearings (AMBs), offering the ability to control the AMB-rotor dynamic behaviors, are preferred in high-precision and micro-vibration applications, such as high-solution Earth observation satellites. However, undesirable harmonic displacements, curre...

The objective of this paper is to implement a reverse engineering process to inspect the geometry of a flow meter rotor and make recommendations to improve the performance of the rotor. The process includes utilizing a laser scanner arm and Geomagic software to generate a three-dimensional (3D) computer model of the flow meter rotor and compare it with the original Computer Aided Drafting (CAD)...

The rotor displacement measurement plays an important role in an active bearing system, however, in practice this measurement might be quite noisy, so that the control performance might be seriously degraded. In this paper, a soft sensing method for magnetic bearing-rotor system based on Support Vector Regression (SVR) and Extended Kalman Filter (EKF) is proposed. In the proposed method, SVR te...

We address the problem of H 1 gain-scheduling of a magnetic bearing/rotor system with the speed of the rotor being the scheduling parameter. The rotor exhibits signiicant gyroscopics. As a result, the plant dynamics change with the rotor speed. Recent results in the theory of LPV systems can be used to design robust, gain-scheduled controllers for such a system. As opposed to traditional gain-s...

This paper presents two design-and-analysis cases of a linestart axial-flux permanent-magnet motor: with solid rotor and with composite rotor. For a novel structure of the motor, two concentric unilevel spaced raised rings are added to the inner and outer radii of its rotors to enable auto-start capability. The composite rotor was coated by a thin (0.05 mm) layer of copper. The basic equations ...

This study concerned the dynamic behavior of the wind turbine rotor. Before all we have studied the loads applied to the rotor, which allows the knowledge their effect on the fatigue, also studied the rotor with longitudinal crack in order to determine stress, strain and displacement. Firstly we compared the first six modes shapes between cracking and uncracking of HAWT rotor. Secondly we show ...