Search published articles


Showing 4 results for Control Strategy
DFIG Based Wind Turbines Behavior Improvement during Wind Variations using Fractional Order Control Systems
M. Hosseinabadi, H. Rastegar,
Volume 10, Issue 4 (12-2014)
Abstract
This paper is concerned with behavior analysis and improvement of wind turbines with Doubly Fed Induction Generator (DFIG) when using a new fractional-order control strategy during wind variations. A doubly fed induction generator, two types of variable frequency power electronic converters and two input wind waveforms are considered. A fractional-order control strategy is proposed for the wind turbine control unit. Output parameters of the wind turbine are drawn by simulations using MATLAB/Simulink for both fractional-order and integer-order (classic) control systems and a complete comparison between these two strategies has been presented. Results show a better operation when using fractional-order control system.
Modeling and Efficient Control of Microturbine Generation System With Battery Energy Storage for Sensitive Loads
P. Asgharian, R. Noroozian,
Volume 15, Issue 1 (3-2019)
Abstract

Microturbine generation system is one of the most promising and a fast growing distributed generation sources. It is used in various applications thanks to high efficiency, quick start and high reliability. Combination of the microturbine and storage system (e.g. battery bank) is desirable selection to satisfy the load requirements under all conditions and hence the battery bank can play an important role in restoring balance between source and demand. In this paper, modeling of the microturbine with battery energy storage system is presented to supply sensitive loads. Appropriate power exchange between battery and the microturbine is an essential issue so, a new control method is proposed for battery energy storage based on instantaneous value of DC-link voltage. In this new strategy, DC-link voltage as well as battery parameters (current and voltage) are used in order to produce desirable DC-DC switching. A control scheme based on voltage, current and frequency measurement is presented for the corresponding inverter. Simulations are carried out in MATLAB/Simulink software and the results show that storage along with proper control improves system reliability to supply sensitive load. The proposed configuration can be used as a remote power, emergency power and also in micro-grid.


Modeling and Control of Water Level in Boiler Drum for Nassiriyah Thermal Power Plant
A. Fadhil Halihal,
Volume 15, Issue 2 (6-2019)
Abstract
The boiler drum process is a nonlinear, complex and multivariable process which includes significant time delay. Therefore, the control on the water level in the drum is not easy and ideal. The first objective of this paper is to model the drum water level referring to 210 MW power unit for Nassiriyah thermal power plant. The second objective is to study the water level controller operation with its performance investigation. Firstly, the drum water level process has been modelled based on first principles by two models: the proposed simplified linearized model and the complicated nonlinear model. Then, a comparison between the extracted practical plant data and the water level results simulated by the two models demonstrate the validity of both models with very good approximations. Secondly, Proportional Integral (PI) controller based on three element water level control strategy and used in this plant, has been described and simulated by MATLAB/Simulink. The controller parameters have been selected according to practical considerations. These considerations are minimizing as possible, a number of the close and open commands to the feedwater flow control valve to extend its lifetime with maintaining the drum water level on a set point. The controller has been tested to evaluate its performance for different values of proportional gain (Kp), integral gain (Ti), gain of steam flow signal (Gx2), and gain of mass feedwater flow signal (Gx3). Firstly, the results show that selection of Kp is difficult because of the tradeoff between fast dynamic response and steady state performance. Secondly, the results show selection of Ti affects only steady state performance. Finally, the results show that selection of Gx2 and Gx3 plays an important role in stability of the drum water level.

Enhancement of Power Quality in Grid Integrated System using DC-link Voltage PI Controlled VSC based Statcom
P. Lakshman Naik, H. Jafari, T. Sudhakar Babu, A. Anil, S. Venkata Padmavathi, D. Nazarpour,
Volume 19, Issue 2 (6-2023)
Abstract
This paper demonstrates an enhancement of power quality in grid integrated systems with the help of the proposed control strategy for voltage source converter based active power filters. The Shunt Active Power filters (SAPF) are extensively utilized in modern grid integrated systems to diminish the power quality concerns associated with it. The SAPF is one of the various power filters, which has better dynamic performance. The SAPF requires an accurate control strategy that provides robust performance under source and loads unbalance conditions. The proposed control scheme is responsible for generating the gate signals to activate the operation of Voltage Source Converter (VSC) based Active Power Filter. Thus, the performance of mitigation of harmonics of source current principally depends on the adopted algorithm. The present paper represents a performance study of a control scheme to mitigate power quality issues in the grid integrated system. The proposed system is modelled and simulated in MATLAB-Simulink in Simpower system block set.

Page 1 from 1     
Creative Commons License
© 2022 by the authors. Licensee IUST, Tehran, Iran. This is an open access journal distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.