Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 34 for “"active damping"”.
-
Semi-active damping of heavy vehicles.
This thesis is concerned with the use of semi-active suspensions in heavy vehicles to improve ride and reduce road damage. An introduction into the subject is given in chapter 1 and a review of the relevant literature is presented at the beginning of each main chapter. The development and modelling …
-
Semi-active damping control for vibration isolation of base disturbances
This thesis is concerned with semi-active damping control for vibration isolation of base disturbances. The aim is to investigate the effectiveness and suitability of semi-active damping control strategies for improving steady-state vibration isolation. A single-degree-of-freedom (SDOF) system, …
-
Smart double panel with decentralised active damping units for the control of sound transmission
… study of a smart aircraft double panel for active vibroacoustic control. The control of the double panel vibration is implemented using Multi-Input-Multi-Output (MIMO) decentralised velocity feedback loops. The loops are applied via an array of electrodynamic force actuators and collocated …
-
Active damping of a structure with low-frequency and closely- spaced modes: experiments and theory
This thesis covers the investigation of active damping on a cruciform beam laboratory structure along with the development of this structure. Also important to this and other research was the development of a calibration apparatus that produces accurate, repeatable calibrations for several types of …
-
Experimental Investigation and CFD Simulation of Active Damping Mechanism for Propellant Slosh in Spacecraft Launch Systems
… used to mitigate the effects of slosh. An active damping mechanism concept developed here can operate over a large range of slosh frequencies and is much more effective than passive damping devices. Spherical and cylindrical tanks modeled using the ANSYS CFX software package considers the …
-
Active damping of a Bernoulli-Euler beam via end point impedance control using distributed parameter techniques
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.
-
Improvement of Stability of a Grid-Connected Inverter with an LCL filter by Robust Strong Active Damping and Model Predictive Control
… the possibility of instability. In general, active damping is needed to stabilize the system and ensure robust performance in steady-state and dynamic responses. While many active damping methods have been proposed to resolve this issue, capacitor-current-feedback active damping has been most …
-
Experimental-theoretical study of velocity feedback damping of structural vibrations
This study concerns the active damping of structural vibrations through the application of various forms of velocity feedback control. Active damping will be required for large space structures which are performance-sensitive to motion or inaccurate pointing. Several control forms, including …
-
A Comprehensive Experimental Evaluation of Actively Controlled Piezoceramics with Positive Posistion Feedback for Structural Damping
This study evaluates the effectiveness of actively controlled piezoceramics with positive position feedback (PPF) for reducing structural vibrations. A comparison is made between active control with PPF and a parallel resistor-inductor (RLC) shunt technique. The primary objectives of this study are …
-
Investigation of Control Concepts for High-Speed Induction Machine Drives and Grid Side Pulse-Width Modulation Voltage Source Converters
… drives. However, the 3L-NPC VSC is an attractive topology if drastically increased switching frequencies are required. A detailed comparison between a 2L VSC and a 3L-NPC VSC as the machine side converter of the exemplary high-speed induction machine drive is carried out. Voltage-oriented …
-
Estimation of Elastic and Damping Characteristics of Viscoelastically Constrained Carbon Strands
… have low package volume and possess excellent damping characteristics. Substantial damping is required in space since there is no surrounding medium to provide damping. Such a construction uses composites in a fabric form that displays viscoelastic behavior. The viscoelastic behavior is …
-
Flexible dynamic modeling and control for the Remote Manipulator System
… perturbation technique. The last part is a pulse active damping (PAD) control loop which is applied to damp out the system residual vibrations in a fast manner. The integrated control strategy leads to fast end-effector trajectory tracking with less end-effector vibration and fast damping of …
-
Control Design of a Single-Phase DC/AC Inverter for PV Applications
… current feedback is used. This achieves the active damping needed to suppress the LCL filter resonance problem. The outer loop regulates the inverter output current flowing into the grid with a proportional resonant controller and harmonic compensators. With a revised grid synchronization …
-
Anti-sway control of a construction crane modeled as a two-dimensional pendulum
… and to maximize productivity a system for actively damping the crane load has been developed. This paper discusses an active damping system using state feedback control for a crane load modeled as a two-dimensional pendulum. Mathematical analysis indicates that the control theory used to …
-
Dynamic range implications for the effectiveness of semi-active tuned mass dampers
… tuned mass damper (TMD), which acts as a passive damping device in the region of the tuned frequency. However, TMDs exhibit a limited bandwidth and often require a significant mass. Active systems, such as the active mass driver, have been utilized to improve the effectiveness of the TMD concept, …
-
Grid current control methods for MV wind energy conversion systems
… overcoming the resonance problem, passive and active damping are discussed in this chapter as well. For evaluating the control performance or requiring the wind turbine behavior on different scenarios, the latest grid standards are also reviewed. Some suggestions on the grid code modifications …
-
Power Sharing and Power Quality Improvement in Parallel Connected Power Converters in the Microgrid
… power demand in islanded microgrids as well as actively mitigate the resonances and harmonics in grid-connected mode. A modified droop control method with a minimum number of current sensors is investigated to accurately share the active and reactive power demand among the VSCs connected to the …
-
Analysis And Modeling Of The Eds Maglev System Based On The Halbach Permanent Magnet Array
… array geometry was derived and analyzed. A novel active magnetic array was introduced and used in the Halbach array EDS Maglev configuration. Further more, since the system is self-regulated in lateral, roll, pitch, and yaw directions, the control was simplified and can be implemented …
-
Development of a System for Testing Grid-connected Doubly Fed Induction Generators with Implementation of a Three-level Neutral-Point-clamped Converter
… It was found that the application of active damping within the IMC control law resulted in reduced stator current transients during synchronisation. Control voltage excitation for the DFIG rotor circuit was achieved by the implementation of two voltage source converters (VSC’s) …
-
Dynamics and Control for Vibration Isolation Design
… increases when the isolator has passive damping although this does not occur for an isolator implementing active damping. A severe limitation of this system is that it cannot be used when the base and/or equipment are flexible. System flexibility has been considered in previous literature …
Page 1 of 2