scholarly journals Optimal PID Controllers for AVR System Considering Excitation Voltage Limitations Using Hybrid Equilibrium Optimizer

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 265
Author(s):  
Martin Ćalasan ◽  
Mihailo Micev ◽  
Milovan Radulović ◽  
Ahmed F. Zobaa ◽  
Hany M. Hasanien ◽  
...  
Keyword(s):  
Power Systems ◽  
Water Cycle ◽  
Voltage Regulation ◽  
System Stability ◽  
Voltage Regulator ◽  
Excitation Voltage ◽  
Avr System ◽  
Generator Voltage ◽  
Simulation Results ◽  
The Impact

Automatic voltage regulator (AVR) represents the basic voltage regulator loop in power systems. The central part of this loop is the regulator, which has parameters that define the speed of the voltage regulation, quality of responses, and system stability. Furthermore, it has an impact on the excitation voltage change and value, especially during transients. In this paper, unlike literature approaches, the experimental verifications of the impact of regulator parameters on the excitation voltage and current value are presented. A novel hybrid metaheuristic algorithm for obtaining regulator parameters determination of the AVR system, and a novel regulator design taking into account excitation voltage limitation are presented. The proposed algorithm combines the properties and characteristics of equilibrium optimizer and evaporation rate water cycle algorithms. The proposed algorithm is effective, fast, and accurate. Both experimental and simulation results show that the limitation of the excitation voltage increases the settling time of the generator voltage during reference change. Additionally, the simulation results show that the optimal values of PID parameters are smaller for limited excitation voltage values.

Microgrids Emergency Control and Protection

2013 ◽  
Vol 2 (1) ◽  
pp. 78-100 ◽  
Author(s):  
Hassan Bevrani ◽  
Mehrdad Gholami ◽  
Neda Hajimohammadi
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Reactive Power ◽  
Renewable Energy Sources ◽  
Voltage Regulation ◽  
System Stability ◽  
Stable Operation ◽  
Energy Storage Devices ◽  
Control Plan ◽  
Emergency Control

Economical harvesting of electrical energy on a large scale considering the environmental issues is a challenge. As a solution, Microgrids (MGs) promise to facilitate the widely penetration of renewable energy sources (RESs) and energy storage devices into the power systems, reduce system losses and greenhouse gas emissions, and increase the reliability of the electricity supply to the customers. Although the concept of MG is already established, the control strategies and energy management systems for MGs which cover power interchange, system stability, frequency and voltage regulation, active and reactive power control, islanding detection, grid synchronization, following contingencies and emergency conditions are still under development. Like a conventional power system, a Micro-grid (MG) needs emergency control and protection schemes to have secure and stable operation. Since MG can operate in both grid-connected and islanded mode, in addition to the control loops and protection schemes, extra issues must be considered. Transition between two operation modes requires an extra control plan to eliminate and stabilize transients due to mode changing. This paper presents an overview of the key issues and new challenges on emergency control and protection plans in the MG systems. The most important emergency control and protection schemes such as load shedding methods that have been presented over the past years are summarized.

PID Parameters Tuning Based on Wavelet Neural Network for Automatic Voltage Regulator Control System

2012 ◽  
Vol 463-464 ◽  
pp. 1663-1667
Author(s):  
Hai Na Hu ◽  
Wu Wang
Keyword(s):  
Neural Network ◽  
Control System ◽  
Power System ◽  
Synchronous Generator ◽  
Wavelet Neural Network ◽  
System Stability ◽  
Voltage Regulator ◽  
System Control ◽  
Automatic Voltage Regulator ◽  
Avr System

Automatic Voltage Regulator (AVR) was applied to hold terminal voltage magnitude of a synchronous generator at a specified level and its stability seriously affects the security of power system. PID control was applied for AVR system control, but the parameters of PID controller were hard to determine, to overcome this problem, some intelligent techniques should be taken. Wavelet Neural Network (WNN) was constrictive and fluctuant of wavelet transform and has self-study, self adjustment and nonlinear mapping functions of neural networks, so the structure of WNN and PID tuning with WNN was proposed, the tuning algorithm was applied into AVR control system, the simulation was taken with normal BP neural network and WNN, the efficiency and advantages of this control strategy was successfully demonstrated which can applied into AVR system for power system stability.

scholarly journals Short-run impact of electricity storage on CO2 emissions in power systems with high penetrations of wind power: A case-study of Ireland

2016 ◽  
Vol 231 (6) ◽  
pp. 590-603 ◽  
Author(s):  
Eoghan McKenna ◽  
John Barton ◽  
Murray Thomson
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Wind Power ◽  
Carbon Emissions ◽  
Study Data ◽  
System Stability ◽  
Short Run ◽  
Storage Technologies ◽  
The Impact

This article studies the impact on CO2 emissions of electrical storage systems in power systems with high penetrations of wind generation. Using the Irish All-Island power system as a case-study, data on the observed dispatch of each large generator for the years 2008 to 2012 was used to estimate a marginal emissions factor of 0.547 kgCO2/kWh. Selected storage operation scenarios were used to estimate storage emissions factors – the carbon emissions impact associated with each unit of storage energy used. The results show that carbon emissions increase in the short-run for all storage technologies when consistently operated in ‘peak shaving and trough filling’ modes, and indicate that this should also be true for the GB and US power systems. Carbon emissions increase when storage is operated in ‘wind balancing’ mode, but reduce when storage is operated to reduce wind power curtailment, as in this case wind power operates on the margin. For power systems where wind is curtailed to maintain system stability, the results show that energy storage technologies that provide synthetic inertia achieve considerably greater carbon reductions. The results highlight a tension for policy makers and investors in storage, as scenarios based on the operation of storage for economic gains increase emissions, while those that decrease emissions are unlikely to be economically favourable. While some scenarios indicate storage increases emissions in the short-run, these should be considered alongside long-run assessments, which indicate that energy storage is essential to the secure operation of a fossil fuel-free grid.

scholarly journals Electromechanical Study the Wind Energy Conversion System Based DFIG and SCIG Generators

2021 ◽  
Vol 15 ◽  
pp. 102-106
Author(s):  
Samir Bellarbi
Keyword(s):  
Power Systems ◽  
Wind Energy ◽  
Energy Conversion ◽  
Torque Control ◽  
System Stability ◽  
Design Solution ◽  
Induction Generator ◽  
Wind Energy Conversion ◽  
Highly Nonlinear ◽  
The Impact

Generally speaking, asynchronous generators are used more frequently in medium power in wind energy conversion systems WECS applications. Depending on the power electronics converter used in the specific application, the operation of the asynchronous machine can be controlled in nested speed torque loops, using different torque control algorithms. Because WECS are highly nonlinear systems, but with smooth nonlinearities, a possible optimal control design solution can be the maximum power point tracking MPPT in this paper. This research describes a comparison of the power quality for wind power systems based on two generators: the squirrel-cage induction generator (SCIG), the doubly fed induction generator (DFIG). At first, we simulated SCIG and DFIG in MATLAB/Simulink and investigates the impact of this generators on the power system stability for compare the results and to comment on the best option based on the output characteristics of the generator and wind turbine. The technical objective of this research is to choose the most suitable generator adaptive with changing wind speeds and the most energy production

scholarly journals Water Cycle Algorithm Based Power System Stabilizer Robust Design for Power Systems

2015 ◽  
Vol 66 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Navid Ghaffarzadeh
Keyword(s):  
Power Systems ◽  
Power System ◽  
Water Cycle ◽  
Computation Time ◽  
System Stability ◽  
Power System Stabilizer ◽  
Water Cycle Algorithm ◽  
Optimum Parameters ◽  
System Stabilizer ◽  
Power System Oscillations

Abstract Power System Stabilizers (PSSs) are used to enhance damping of power system oscillations. This paper presents a new fast algorithm to develop PSS. According to this regard, Water Cycle Algorithm (WCA) is used to detect optimum Power System Stabilizer parameters. For this purpose, the design problem of PSS is formulated as an optimization problem and WCA by forming three subsidiary objective functions is employed to search for optimal power system stabilizer’s parameters to minimize the maximum overshoot and settling time together. In order to show the efficiency of the proposed algorithm, a comparison between WCA and without PSS condition has been done, and the results of proposed algorithm show that it detects optimum parameters in reasonable computation time to increase the power system stability.

scholarly journals Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

2016 ◽  
Vol 67 (1) ◽  
pp. 21-28
Author(s):  
Sebastian Berhausen ◽  
Stefan Paszek
Keyword(s):  
Parameter Estimation ◽  
Power Systems ◽  
Power System ◽  
Objective Function ◽  
Estimation Method ◽  
Synchronous Generator ◽  
Voltage Regulation ◽  
Operating Conditions ◽  
Synchronous Generators ◽  
Generator Voltage

Abstract In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

scholarly journals Assessing the Impact of Cybersecurity Attacks on Power Systems

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 725 ◽  
Author(s):  
Athanasios Dagoumas
Keyword(s):  
Power Systems ◽  
Power System ◽  
Linear Trend ◽  
Operating Cost ◽  
Energy System ◽  
Operating Conditions ◽  
System Stability ◽  
System Cost ◽  
System Operator ◽  
The Impact

Cybersecurity is an emerging challenge for power systems, as it strongly affects their reliability and the whole energy system cost. The paper uses several Unit Commitments (UC) models, applying different methods to tackle renewables’ uncertainty. The selected power system is IEEE RTS 96. The UC models are used to assess the impact of different cybersecurity threats. The focus is to assess their impact on the total operating cost and the power grid adequacy to handle them. The comparison between the UC models shows that more robust UC models lead to higher total operating costs. The cost, unit dispatching, and energy mix evolution have a non-linear trend, depending on the power system characteristics and the cyberattacks types. However, the paper provides evidence of considerable price signals in the case of the examined cyberattacks. Each Transmission System Operator (TSO) should examine combinations of cyberattacks and operating conditions to identify crucial cases for system stability and power system cost operation. The applied methodology would also require substantial developments or supplementary approaches to assess cyberthreats at the distribution level.

Decentralized Robust Coordinated Controller of Excitation and Valve for Improvement of Power System Stability

2014 ◽  
Vol 668-669 ◽  
pp. 462-465
Author(s):  
Zhi Min Li ◽  
Xin Yang Deng ◽  
Xiao Ming Mou ◽  
Shuang Rong ◽  
Tian Kui Sun ◽  
...  
Keyword(s):  
Power Systems ◽  
Power System ◽  
Control Systems ◽  
Coordinated Control ◽  
Power System Stability ◽  
System Stability ◽  
Control Scheme ◽  
Terminal Voltage ◽  
Simulation Results ◽  
Generator Terminal

A novel robust control scheme for decentralized generator excitation and valve coordinated control systems to improve power system stability is proposed. By utilizing generator terminal voltage magnitude and phase angle to represent the interactions among generators, decentralized generator excitation and valve coordinated control in multi-machine power systems is achieved. The control is realized by robust parametric approach. Simulation results show that the proposed robust parametric coordinated control can improve power system stability.

scholarly journals Characteristic and Surge Impedance Variation Impact on Transmission Line Performance

2018 ◽  
Vol 8 (4) ◽  
pp. 2602
Author(s):  
Muhyaddin J. H. Rawa
Keyword(s):  
Power Systems ◽  
Transmission Line ◽  
Voltage Regulation ◽  
Voltage Profile ◽  
Network Analyses ◽  
Impedance Variation ◽  
The Impact

<span>Modeling of power systems is essential to perform various network analyses. Voltage regulation, line losses and transmission line efficiency are greatly affected by transmission line parameters. Hence, accurate modeling of transmission line is required. The aim of this paper is to study the impact of characteristic and surge impedances on voltage profile, voltage regulation and transmission line efficiency.</span>

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