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Showing 4 results for Load Frequency Control
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Volume 4, Issue 2 (3-2016)
Abstract
Load frequency control (LFC) in power systems is one of the most important issues in the field of optimizing power system performance that attracted the attention of many researchers. In this work, a sliding mode based load frequency control is developed on a three-area interconnected power system. The power system contains non-reheat, reheat, and hydraulic turbines which are distributed in these three areas respectively. Both governor dead band and generation rate constraint are included in the model of this power system. Our control goal is to regulate the frequency error, tie-line power error and area control error despite the presences of external load disturbance and system uncertainties. Additionally, an optimization process is proposed for optimal adjustment of the sliding mode control parameters of each of the three areas, aimed at improving integral performance and step response characteristics such as amount of overshoot, steady state error, and sitting time. The optimization was performed using the particle swarm optimization (PSO) algorithm, which is one of the most powerful algorithms for nonlinear problems solving. The sliding mode based load frequency controller is simulated on this three-area interconnected nonlinear power system. The simulation results verify the effectiveness of the sliding mode controller. In addition, the performance of SMC is compared with an optimized PI controller. The comparison study shows the superiority of the SMC to the PI controller in term of control performance. They also demonstrate the robustness of the sliding mode controller against parameter variations and external disturbances.
Atefeh Hoseini, Dr. Javad Mashayekhifard , Bagher Mohazzabi ,
Volume 12, Issue 2 (9-2023)
Abstract
Power system design and controls are done with stability and reliability. Frequency is one of the important variables to stabilize the speed of engine loads. Considering the vital role of gas turbines in producing electricity without harmful effects on the environment, in this paper, utilizing the Rowen model for the frequency power system, the load-frequency control with the secondary control loop has been examined. For this reason, the design is done by the transfer function and state space. To begin with, the conventional PID controller is designed utilizing CHR and CC calculations in order to increase the system speed, eliminate disturbance and reduce the sum of overshoot. At that point, LQR linear optimal controller is utilized. Finally, due to the uncertainty and disturbance, H2/H∞ robust controller has been considered with the three conditions of nominal performance, robust stability, and reduction of disturbance. The simulation results obtained with/without the presence of disturbance have been checked and compared in MATLAB software. The results of the simulations show the success of the proposed H2/H∞ robust control strategy in terms of convergence rate and fluctuation range among all the control strategies examined.
Dr, Mehdi Riahinasab, Majid Moazzami, Dr. S. Mohamadali Zanjani, Dr. Neda Behzadfar, Dr. Akbar Golsorkhi Esfahani,
Volume 13, Issue 1 (5-2024)
Abstract
Oscillations in electrical power occur in the power system when there is no balance between the demand for power consumption and power generation in a period of time. The frequency should be almost constant at all points of the power system. The load frequency control system (second level control) is used to maintain the frequency in nominal values or close to it. The purpose of active power control is to minimize frequency changes to achieve acceptable power system stability. In this article, the aim is to study and simulate the load frequency control system in the power system with gas turbine power plant. The frequency depends on the parameters of the power system and the differences in the parameters cause a slight deviation in the frequency of the system. The simulation results in the time domain have been determined using MATLAB software. System modes are checked for different system parameters and the effect of parameter changes on power system stability is shown.
Dr, Mohammadreza Moradian, Dr, Majid Moazzami, Dr, Ghazanfar Shahgholian,
Volume 13, Issue 2 (8-2024)
Abstract
Stability and reliability have become very important due to the integration of renewable energy sources and the dynamic nature of load demand in power systems. Frequency stability is an important indicator of power quality in electrical power systems. Load frequency control by maintaining the system frequency at the nominal value plays an important role in the efficient operation and ensuring the stability of the power system. Any sudden disturbance in the load can cause changes in the power exchange in the transmission line between regions, and create frequency fluctuations in the power system. The purpose of this research is to analyze and simulate the dynamic behavior of load frequency control in a single-zone power system consisting of two energy sources: a thermal turbine equipped with a preheater and a hydro turbine equipped with a transient drop compensator. The effect of the photovoltaic system on frequency deviation changes in the power system has also been investigated. The first-order equations of the power system are expressed in state space and the modes of the system have been determined. The simulation results using Simulink/MATLAB software and model analysis using eigenvalue analysis of the system matrix show the dynamic behavior of the power system for changes in the consumed load.
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