Abstract This paper provides a systematic analysis of the large scale PMSG (permanent magnet synchronous generator)-based WECS (wind energy conversion system) torsional vibration problem under MPPT (maximum power point tracking) control and constant control. is from perspective SSO (sub-synchronous oscillation), SSH harmonics) forced vibration. The cause negative total system damping, weakened ...

Analysis of the free and forced vibration responses beams is one most critical problems to be examined in design step these structural members. The finite-element method which solves boundary value can applied efficiently problems. In this study, natural frequency damped undamped transient analyses pinned-pinned are investigated. well-known software packages, ANSYS SAP2000, used. 2-D elastic be...

Numerical simulations of the interaction between a circular cylinder and its wake during both forced and free, vortex-induced, oscillation have been performed using a spectral element method in which the computational mesh was fixed to the cylinder and the Navier-Stokes equations solved in this accelerating reference frame. Thus far, work has focussed on cross flow, rather than in-line oscillat...

Difference thresholds for seated subjects exposed to whole-body vertical sinusoidal vibration have been determined at two vibration magnitudes [0.1 and 0.5 ms(-2) root mean square (r.m.s.)] and at two frequencies (5 and 20 Hz). For 12 subjects, difference thresholds were determined using the up-and-down transformed response method based on two-interval forced-choice tracking. At both frequencie...

The study on local modes as a molecule's eigen-vibration is still an attracting topic [1,2]. However, a new trend becomes more popular: people are more interested in the vibration properties of molecules under interactions with external laser fields for practical usages such as bond-selective photodesorption [3, 4] and vibrationally mediated dissociation [ 5 7 ] . We have already studied the po...