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Robust Motion Tracking Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici Jan 2006

Robust Motion Tracking Control Of Piezoelectric Actuation Systems, Hwee Choo Liaw, Denny Oetomo, Bijan Shirinzadeh, Gursel Alici

Faculty of Engineering - Papers (Archive)

This paper proposes a robust control methodology for piezoelectric actuation systems to track specified motion trajectories. This is motivated by the search for an effective control strategy to deal with the problem of nonlinear behaviour in the piezoelectric actuation systems. The basic concept associated with this approach lies in the specification of a target performance and the formulation of a robust control scheme for the system to ensure the convergence of the position tracking error to zero in the presence of parametric uncertainties and hysteresis effect inclusive of other un-modelled disturbances. Stability of the control system is proven theoretically and …


Characterisation And Control Of A Prototype Hts Smes Device, Christopher J. Hawley, Dominic Cuiuri, Christopher D. Cook, Steve Gower, Timothy Beales Jan 2006

Characterisation And Control Of A Prototype Hts Smes Device, Christopher J. Hawley, Dominic Cuiuri, Christopher D. Cook, Steve Gower, Timothy Beales

Faculty of Engineering - Papers (Archive)

A 2.79 kJ prototype high transition temperature Superconducting Magnetic Energy Storage (SMES) device has been constructed. The coil for the prototype has been wound using High Temperature Superconducting (HTS) BSCCO-2223 tape. The refrigeration system is a gaseous helium cold head cryocooler used to maintain the SMES coil at a temperature of 30 K, improving the Ic characteristic of the coil by a factor of 4.7 compared to that at 77 K. The SMES device is capable of supplying a 3-phase load during power interruptions, and has been constructed during a program to develop a larger 20 kJ system aimed at …


Distributed Generation Control Using Protection Principles, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2006

Distributed Generation Control Using Protection Principles, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2006

Control Stabilisation Of An Islanded System With Dfig Wind Turbine, M Aktarujjaman, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Distributed Generation (DG) is often used to export power to the utility system. Loss of main supply can cause a severe loading mismatch between DG generation and load consumption. Consequently, the voltage and frequency of the islanded system will cross the allowable limit. Due to this fact, it is essential to control the voltage and frequency in the islanding mode of operation. In this paper, control stabilisation of an islanded system with a doubly-fed induction generator (DFIG) wind turbine has been addressed. Wind DG produces variable output and is not capable to produce enough reactive power. Hence, it is imperative …


Control Strategy Of Distributed Generation For Voltage Support In Distribution Systems, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich Jan 2006

Control Strategy Of Distributed Generation For Voltage Support In Distribution Systems, An D. T Le, Kashem M. Muttaqi, Michael Negnevitsky, Gerard Ledwich

Faculty of Engineering and Information Sciences - Papers: Part A

Voltage problem is always a critical issue in operating a distribution system. The uncertainties of load distribution and variation have introduced a great complexity to the task of maintaining system voltage within the permitted range. In this paper, small-scale generator, known as distributed generation (DG), is employed in the system and acting as a voltage regulator. The output of DG is controlled in such a way that acceptable level of electrical supply quality is achieved with a reasonable operating cost. The DG controller is tested with a non-uniformly varying load on the time domain basis. Simulations have been conducted with …


Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici Jan 2006

Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici

Faculty of Engineering - Papers (Archive)

This paper proposes and evaluates an adaptive technique and a variable structure control approach for piezoelectric actuation systems to track specified motion trajectories. The proposed control methodologies are formulated to accommodate unknown or uncertain system parameters, nonlinearities including the hysteresis effect, and external disturbances in the piezoelectric actuation systems without any form of feed-forward compensation. In this study, both control methodologies are demonstrated to possess a promising motion tracking ability experimentally. In comparison, the variable structure control approach is evaluated to be superior to the adaptive technique in the motion tracking control. With the ability to track motion trajectories under …


Hydro-Turbine Governor Control: Theory, Techniques And Limitations, J Culberg, Michael Negnevitsky, Kashem M. Muttaqi Jan 2006

Hydro-Turbine Governor Control: Theory, Techniques And Limitations, J Culberg, Michael Negnevitsky, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

With the entry of Tasmania into the national electricity market, equipment upgrades are required in many parts of the existing power system. This presents an opportunity to embrace new technology, in order to enhance the current efficiency and productivity of the system. One area is that of hydro-turbine speed governors, an integral part of maintaining the frequency of the output. This paper analyses the current standard control algorithm for turbine governors, the PID controller. It illustrates the processes involved, tuning and their limitations. Finally, alternative control systems are discussed.


Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh Jan 2006

Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh

Faculty of Engineering - Papers (Archive)

This paper presents a special class of positive definite functions for the formulation of adaptive control strategies, specifically in the research of an effective control algorithm for piezoelectric actuation systems in micro/nano manipulation. To deal with the control problems of unknown system parameters, nonlinear hysteresis effects, and disturbances in the piezoelectric actuation systems, an adaptive control methodology is proposed. Using the saturation function derived from a positive definite function to formulate the control methodology, the closed-loop system stability can be guaranteed. Furthermore, the control methodology is proposed to track a desired motion trajectory in position, velocity, and acceleration. In this …