Nowadays it is commonly considered that high damping materials which have both the good mechanical properties as structural materials and the high damping capacity for vibration damping are the most direct vibration damping solution. In metals and alloys however, exhibiting simultaneously high damping capacity and good mechanical properties has been noted to be normally incompatible because the...

It is vital to improve the stability of power system by accurately identifying modal parameters damped low-frequency oscillations (DLFO) and controlling oscillation in time. A new method based on empirical mode decomposition (EMD), stochastic subspace identification (SSI), Prony algorithms, called synthetical (SMPI) method, developed efficiently matching DLFO which are acquired from SSI algorit...

The paper deals with analysis of loading conditions on damping torque coefficient and synchronizing coefficient in SMIB system and design of Delta-Omega type of damping controller for damping of power oscillations in the system. Effect of variation of loading on synchronizing torque and damping torque coefficients has been investigated in detail. A new design approach for optimizing the paramet...

A new compact model of squeeze-film damping is developed based on the numerical solution of the Boltzmann kinetic equation. It provides a simple expression for the damping coefficient and the quality factor valid through the slip, transitional and free-molecular regimes. In this work, we have applied statistical analysis to the current model using the chi-squared test. The damping predictions a...

We determine the class of damped modes ỹ which are related to the common free damping modes y by supersymmetry. They are obtained by employing the factorization of Newton’s differential equation of motion for the free damped oscillator by means of the general solution of the corresponding Riccati equation together with Witten’s method of constructing the supersymmetric partner operator. This pr...

Positrons collected at the SLC positron source are transported over a 2-km path at 220 MeV to be reinjected into the linac for acceleration to 1.2 GeV, the energy of the emittance damping ring. Since the positron bunch length is a significant fraction of a cycle of the linac-accelerating RF, the energy spread at 1.2 GeV is considerably larger than the acceptance of the linac-toring (LTR) t rans...

This paper investigates damping ratio in micro-beam resonators based on magneto-thermo-elasticity. A unique aspect of the present study is the effect of permanent magnetic field on the stiffness and thermo-elastic damping of the micro resonators. In our modeling the theory of thermo-elasticity with interacting of an externally applied permanent magnetic field is taken into account. Combined the...

In this paper, the Unified Power Flow Controller (UPFC) is enhanced with a Chaotic Particle Swarm Optimization (CPSO) Damping Controller in order to mitigate the Low Frequency Oscillations (LFO) in a Single Machine Infinite Bus (SMIB) power system. The designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the out...