Rossander, M. 2017. Electromechanics of Vertical Axis Wind Turbines. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1581. 81 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0117-4. Wind power is an established mean of clean energy production and the modern horizontal axis wind turbine has become a common sight. The need for maint...

The paper describes the analysis, design and control of two new versions of spherical permanent magnet motor, which are capable of two and three degrees-of-freedom of controlled motion, and have a high specific torque capability. Their magnetic field distribution is established using an analytical technique formulated in spherical coordinates. This enables the torque vector and back-emf to be d...

The self-synchronization of spin torque oscillators is investigated experimentally by re-injecting its radiofrequency (rf) current after a certain delay time. We demonstrate that the integrated power and spectral linewidth are improved for optimal delays. Moreover by varying the phase difference between the emitted power and the re-injected one, we find a clear oscillatory dependence on the pha...

The purpose of this paper is to describe a model predictive direct torque control (MPDTC) with load angle limitation for surface-mounted permanent magnet synchronous motor (SPMSM) drive system. In this paper, an exact discrete-time state-space model of SPMSM is presented, which improves the state prediction accuracy comparing to simple Euler approximation. A finite control set type MPDTC is use...

accurate delivery of torque to implant screws is critical to generate ideal preload in the screw joint and to offer protection against screw loosening. mechanical torque-limiting devices (mtlds) are available for this reason. in this study, the accuracy of one type of friction-style and two types of spring-style mtlds at baseline, following fatigue conditions and sterilization processes were de...

− This paper gives details of a round robin torque comparison involving the National Physical Laboratory (NPL) and nine other UK laboratories. The comparison covered two ranges: 20 N·m to 100 N·m and 200 N·m to 1 kN·m. The work was an effective way of disseminating the unit of torque to industry via the UK’s new national torque standard, giving assurance to laboratories and customers and identi...

Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs). A sliding mode controller (SMC) based on the exponential reaching law for the anti-lock braking system (ABS) is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC). A regenerative braking algorithm, in which t...

The purpose of this investigation was to examine the effect of the supine and prone position on concentric and eccentric isokinetic strength of the hamstring muscle group. Twelve university female lacrosse players were tested for hamstring average torque on a Kinetic Communicator(R) dynamometer at 60 degrees /sec from the supine and prone positions. Analysis of variance indicated average torque...

Previous studies have indicated that the variations in torque induced in particles in electrorotation electrode arrays are sufficiently large to cause errors in electrorotation measurements. In order to avoid this, experimenters usually study particles bounded by an arbitrary region near the centre of the electrodes. By simulating the time-dependent electric field for polynomial electrodes, we ...