Adaptive Estimation of Components of a Three-Phase Signal Polluted with Sinusoidal Disturbance

, M.Sc. Thesis Sharif University of Technology Shafiee, Ashkan (Author) ; Karimi, Houshang (Supervisor)

Abstract

This thesis proposes a new method for estimation of parameters of a multi-component signal. The signal is composed of several sinusoidal components whose frequencies and magnitudes are unknown. Moreover, the signal is polluted with white noise. The estimated parameters are frequency, amplitude, and phase-angle of each component. The proposed method is able to adaptively decompose the multi-component signal into its constituting sinusoidal components. The core unit of the proposed method comprises an adaptive band-pass and an adaptive notch filter. The proposed method consists of parallel connection of several core units. The band pass filter rejects all components except the one whose...

Stabilization of Subsynchronous Oscillations of ILAM Refinery Gas Turbine Units in Islanded Operations

, M.Sc. Thesis Sharif University of Technology Sheikhi, Mostafa (Author) ; Mokhtari, Hossein (Supervisor)

Abstract

Ilam refinery has three synchronous generator units each with a capacity of 26.5 MVA and two six-phase LCI-fed synchronous compressors, each with a capacity of 8 MW. Generators of Ilam gas refinery have instability issue in case of island operation. With launching one generator unit and then connecting two compressors the instability problem and tripping of the generators appear. Given the importance of this issue, various tests and corresponding measurements in both electrical and mechanical aspects were carried out at the plant in on-grid and island operations to analyze the cause of instability phenomena. The mechanical part of tests analyses the frequency of oscillations and vibration in...

Study and Improvement of Stability of Generator-based Distributed Generation units Inpresence of Large Nonlinear Loads

, M.Sc. Thesis Sharif University of Technology Afzali, Kiana (Author) ; Mokhtari, Hossein (Supervisor)

Abstract

Hyderogels are hydrophilic polymers with three dimensional network structure, due to their high water absoption, their application to life and industry is increasing from day to day, such as tissue engineering, actuators and sensors, drug delivery and therapeutic treatment. In this project, it has been attempted to produce polyacrylamide/alginate double network hydrogels with the use of graphene oxide nanosheets to indicate that it is possible to combine toughness and self-healing in a hydrogel with the opposite nature of each other. To evaluate mechanical properties, uniaxial tensile test and loading-unloading test were used. The results indicate that increase the weight ratio of acrylamide...