In this paper we propose a new control scheme for the doubly–fed induction machine (DFIM) that offers significant advantages, and is considerably simpler, than the classical vector control method. In contrast with the latter, where the DFIM is represented in a stator flux–oriented frame, we propose here a model with orientation of the stator voltage. This allows for an easy decomposition of the...

This paper presents the parameters of permanent magnet synchronous motor i.e. speed (r), stator resistance (RS), q-axis inductance (Lq), and torque (Ts) is to be estimated by using Model Reference adaptive System(MRAS). To improve the performance of speed sensor less permanent magnet synchronous motor drives, especially at low speeds by identifying stator resistance together with speed. Severa...

Body size varies considerably among species and among populations within species, exhibiting many repeatable patterns. However, which sources of selection generate geographic patterns, and which components of fitness mediate evolution of body size, are not well understood. For many animals, resource quality and intraspecific competition may mediate selection on body size producing large-scale g...

A low voltage drive linear ultrasonic motor with a semi-oval shaped stator is proposed in this paper. In the stator, two multilayer piezoelectric actuators are clamped in the holder of the stator by pre-stressing to excite a semi-oval ring. The semi-oval shaped stator is designed to have normal vibration and tangential vibration modes, thus these two orthogonal mechanical vibration modes of the...

A carbon nanotube [CNT]/Co3O4 composite is introduced as a catalyst for the air electrode of lithium-air [Li/air] batteries. Co3O4 nanoparticles are successfully attached to the sidewall of the CNT by a hydrothermal method. A high discharge capacity and a low overvoltage indicate that the CNT/Co3O4 composite is a very promising catalyst for the air electrode of Li/air batteries.

OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Andrej Burakov Name of the dissertation Modelling the unbalanced magnetic pull in eccentric-rotor electrical machines with parallel windings Manuscript submitted 08.06.2007 Manuscript revised 07.10.2007 Date of the defence 25.10.2007 Monograph Article dissertation (summary + original ...

The bacterial flagellar motor is driven by the electrochemical potential of specific ions, H(+) or Na(+). The motor consists of a rotor and stator, and their interaction generates rotation. The stator, which is composed of PomA and PomB in the Na(+) motor of Vibrio alginolyticus, is thought to be a torque generator converting the energy of ion flux into mechanical power. We found that specific ...

This paper deals with the design and performance analysis of double stator axial flux permanent magnet generators for rim-driven marine current turbines (MCT). Indeed for submarine applications, drive train reliability is a key feature to reduce maintenance requirements. Rim-driven direct-drive multi-stator generators can therefore be a very interesting solution to improve this reliability. In ...

PomA and PomB are transmembrane proteins that form the stator complex in the sodium-driven flagellar motor of Vibrio alginolyticus and are believed to surround the rotor part of the flagellar motor. We constructed and observed green fluorescent protein (GFP) fusions of the stator proteins PomA and PomB in living cells to clarify how stator proteins are assembled and installed into the flagellar...

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...