Timely remote activation of frequency response, provided by converter-based generation, can improve the damping very low-frequency (VLF) oscillations. The research presented is based on both power system models and actual data from phasor measurement units (PMU) Irish system. performance active control (APC) investigated, variations in wind speed, droop, time lag resource capacity demonstrate t...

This paper presents a systematic methodology for design and tuning of the current controller in LCL gridconnected converters for wind turbine applications. The design target is formulated as a minimization of the current loop dominant time constant, which is in accordance with standard design guidelines for wind turbine controllers (fast time response and high stability margins). The proposed a...

Hybrid Stepper Motors (HSM), together with the microstepping driving technique, are widely used in many motion control applications, given their low cost and high reliability. On the other hand, being controlled in an open loop fashion, they cannot achieve high levels of performance, this mainly due to the absence of a load-side position sensor. In this paper, we address the problem of controll...

Acknowledgements In the beginning, I would like to express my sincere gratitude to my supervisor professor André Preumont, the head of the Active Structures Laboratory for his patience, wise advices, brilliant ideas and suggestions and for his strong insistance and high pressure to achieve better work. I would like to thank my colleagues: Frédéric Bossens for putting my feet on the right way, M...

Design The feasibility study, focuses on building up knowledge of and experience with the technology of using the "d31-effect" of piezoelectric material to damp the internal vibrations of the system. The investigation starts by specifying the mathematical relations that describes the piezoelectric "d31-effect" and particularising these relations for the actuator and sensor situation. The two vi...

A transient perturbation applied to a limb held in a given posture can induce oscillations. To restore the initial posture, the neuromuscular system must provide damping, which is the dissipation of the mechanical energy imparted by such a perturbation. Despite their importance, damping properties of the neuromuscular system have been poorly characterized. Accordingly, this paper describes the ...

Linear, friction-induced vibration and aeroelastic flutter problems are governed by second-order differential equations of motion in which the stiffness matrix and often damping matrix are asymmetric. Asymmetric systems are prone to unstable vibration (flutter) as a parameter reaches a critical value, when the real part of a pair of complex poles crosses the vertical imaginary axis of the s-pla...

In the context of aircraft, shimmy is an oscillatory phenomenon of the landing gear mainly due to the tire and the landing gear structural dynamics. This phenomenon which can result in severe damage to the landing gear must be damped. This paper presents a new nose landing gear model including an actuator model and a simple tire/road interface description approximating the Pacejka model to allo...

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Recent studies suggest that fruit flies use subtle changes to their wing motion to actively generate forces during aerial maneuvers. In addition, it has been estimated that the passive rotational damping caused by the flapping wings of an insect is around two orders of magnitude greater than that for the body alone. At present, however, the relationships between the active regulation of wing ki...