scholarly journals Coordinated Excitation and Static Var Compensator Control with Delayed Feedback Measurements in SGIB Power Systems

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2181
Author(s):  
Haris E. Psillakis ◽  
Antonio T. Alexandridis
Keyword(s):  
Power Systems ◽  
Time Delays ◽  
Feedback Linearization ◽  
Output Voltage ◽  
Transient Stability ◽  
Synchronous Generator ◽  
Static Var Compensator ◽  
Large Power ◽  
Measurement Feedback ◽  
Approach Zero

In this paper, we present a nonlinear coordinated excitation and static var compensator (SVC) control for regulating the output voltage and improving the transient stability of a synchronous generator infinite bus (SGIB) power system. In the first stage, advanced nonlinear methods are applied to regulate the SVC susceptance in a manner that can potentially improve the overall transient performance and stability. However, as distant from the generator measurements are needed, time delays are expected in the control loop. This fact substantially complicates the whole design. Therefore, a novel design is proposed that uses backstepping methodologies and feedback linearization techniques suitably modified to take into account the delayed measurement feedback laws in order to implement both the excitation voltage and the SVC compensator input. A detailed and rigorous Lyapunov stability analysis reveals that if the time delays do not exceed some specific limits, then all closed-loop signals remain bounded and the frequency deviations are effectively regulated to approach zero. Applying this control scheme, output voltage changes occur after the large power angle deviations have been eliminated. The scheme is thus completed, in a second stage, by a soft-switching mechanism employed on a classical proportional integral (PI) PI voltage controller acting on the excitation loop when the frequency deviations tend to zero in order to smoothly recover the output voltage level at its nominal value. Detailed simulation studies verify the effectiveness of the proposed design approach.

scholarly journals Analysis and design of different controllers for non-linear power systems

2013 ◽  
Vol 2 (3) ◽  
pp. 216
Author(s):  
Rekha Chaudhary ◽  
Arun Kumar Singh
Keyword(s):  
Power Systems ◽  
Power System ◽  
Feedback Linearization ◽  
Transient Stability ◽  
Voltage Regulation ◽  
Analysis And Design ◽  
Non Linear ◽  
Terminal Voltage ◽  
Initial Power ◽  
Direct Feedback

The objective of this paper is to design controller for non-linear power system using Direct Feedback Linearization technique to improve the transient stability and to achieve better voltage regulation. In case of fault in the power system, power angle and the terminal voltage are the parameters which are to be monitored. The simulation has been carried out taking different values of initial power angles and results were obtained for power angle and terminal voltage. To overcome the demerits of DFL-LQ optimal controller and DFL voltage regulator, co-ordinated controller is proposed. Simulation results show that transient stability of a power system under a large sudden fault has been improved by using co-ordinated controller.

scholarly journals Transient Stability Control Based on Kinetic Energy Changes Measured by Synchronized Angular Velocity

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6893
Author(s):  
A. F. Diaz-Alzate ◽  
John E. Candelo-Becerra ◽  
Albert Deluque-Pinto
Keyword(s):  
Kinetic Energy ◽  
Angular Velocity ◽  
Power Systems ◽  
Real Time ◽  
Transient Stability ◽  
Stability Control ◽  
Area Measurement ◽  
Velocity Signal ◽  
Large Power ◽  
Time Operation

Real-time transient stability studies are based on voltage angle measures obtained with phasor measurement units (PMUs). A more precise calculation to address transient stability is obtained when using the rotor angles. However, these values are commonly estimated, which leads to possible errors. In this work, the kinetic energy changes in electric machines are used as a criterion for evaluating and correcting transient stability, and to determine the precise time of insertion of a special protection system (SPS). Data from the PMU of the wide-area measurement system (WAMS) are used to construct the SPS. Furthermore, it is assumed that a microcontroller can be located in each generation unit to obtain the synchronized angular velocity. Based on these measurements, the kinetic energy of the system and the respective control action are performed at the appropriate time. The results show that the proposed SPS effectively corrects the oscillations fast enough during the transient stability event. In addition, the proposed method has the advantage that it does not depend on commonly proposed methods, such as system models, the identification of coherent machine groups, or the structure of the network. Moreover, the synchronized angular velocity signal is used, which is not commonly measured in power systems. Validation of the method is carried out in the New England power system, and the findings show that the method is helpful for real-time operation on large power systems.

Dynamic Performance Enhancement of Synchronous Generator Excitation via Nonlinear Backstepping Control

2017 ◽  
Vol 18 (4) ◽  
Author(s):  
Haitham Saad Mohamed Ramadan ◽  
Mohamed Becherif
Keyword(s):  
Power Systems ◽  
Transient Stability ◽  
Performance Enhancement ◽  
Dynamic Performance ◽  
Synchronous Generator ◽  
Nonlinear Character ◽  
Synchronous Generator Excitation ◽  
Single Machine Infinite Bus ◽  
The Stability ◽  
Nonlinear Backstepping Control

Abstract This paper addresses the transient stability problem in power systems of nonlinear character. A recursive nonlinear backstepping controller for improving the single machine infinite bus system’s dynamic behavior is proposed for the system global stabilization considering the network transfer conductances. Despite parameters uncertainties, nonlinear dynamics and/or disturbances, the feedback laws based on the backstepping approach are explicitly derived and the conservatism of the stability property is guaranteed for both lossy and lossless power system representations. Simulation results, via MATLAB™-Simulink, reveal that the proposed backstepping technique can be feasibly designed to ensure significant dynamic performance enhancements.

scholarly journals Rated Power Determination for Autonomous Micro Combined Heat and Power and Rechargeable Battery System

2020 ◽  
Vol 57 (6) ◽  
pp. 12-22
Author(s):  
A. Fedotov ◽  
G. Vagapov ◽  
L. Grackova ◽  
R. Abdullazyanov
Keyword(s):  
Energy Efficiency ◽  
Power Systems ◽  
Fossil Fuels ◽  
Synchronous Generator ◽  
Combined Heat And Power ◽  
Rechargeable Batteries ◽  
Large Power ◽  
Increase Energy Efficiency ◽  
Operation Process ◽  
Key Issues

AbstractAn autonomous micro combined heat and power (Micro-CHP) is usually installed to increase energy efficiency and reduce energy costs in areas remote from large power systems. The main goal of autonomous Micro-CHP is to provide residential and industrial areas with electricity and heat. By designing an autonomous Micro-CHP, one of the key issues is the determination of rated power, since the energy efficiency of equipment and the costs of fossil fuels depend on the rated power. The mathematical model can better calculate the necessary rated power for an autonomous Micro-CHP in the case of operation with rechargeable batteries. Overall, the results have shown that the engine characteristics, operation process of three-phase synchronous generator and statistical information on loads are the criteria for improving energy efficiency.

scholarly journals Analysis of Inertia Characteristics of Direct-Drive Permanent-Magnet Synchronous Generator in Micro-Grid

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3141 ◽  
Author(s):  
Donghui Zhang ◽  
Yongbin Wu ◽  
Liansong Xiong ◽  
Chengyong Zhao
Keyword(s):  
Power Systems ◽  
Time Scale ◽  
Structural Parameters ◽  
Synchronous Generator ◽  
Droop Control ◽  
Grid System ◽  
Direct Drive ◽  
Large Power ◽  
Micro Grid ◽  
Inertia Control

Micro-grid has received extensive attention as an effective way to absorb new energy. Compared to large power systems, the micro-grid system consisting of power electronics is relatively weak due to the lack of support for synchronous machines. In this paper, the direct-drive wind turbine (WT) is connected to the low-inertia micro-grid as the research background. Based on the virtual inertia control of the WT, the inertia source and the physical mechanism of the WT connected to the micro-grid system are studied. The inertia characteristics of the rotor of the WT on the electromechanical time-scale, the DC side capacitor on the DC voltage time-scale, and the simulated grid under the droop control are analyzed. The research results show that under the control of the system, the inertia of the system is derived from the WT, DC capacitor, and the micro-grid simulated by droop control converter. The equivalent inertia of each link is determined by the control parameters, steady-state operating point, and structural parameters. The resulting inertia characteristics will have frequency domain characteristics under control. Finally, the correctness of the system inertia analysis conclusion is verified by simulation and experiment.

scholarly journals Immersion and Invariance-Based Coordinated Generator Excitation and SVC Control for Power Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Adirak Kanchanaharuthai
Keyword(s):  
Power Systems ◽  
Small Perturbation ◽  
Feedback Linearization ◽  
Transient Stability ◽  
Dynamic Properties ◽  
Voltage Regulation ◽  
Nonlinear Controller ◽  
Electrical Power System ◽  
Immersion And Invariance ◽  
Large Perturbation

A nonlinear coordinated control of excitation and SVC of an electrical power system is proposed for transient stability, and voltage regulation enhancement after the occurrence of a large disturbance and a small perturbation. Using the concept of Immersion and Invariance (I&I) design methodology, the proposed nonlinear controller is used to not only achieve power angle stability, frequency and voltage regulation but also ensure that the closed-loop system is transiently and asymptotically stable. In order to show the effectiveness of the proposed controller design, the simulation results illustrate that, in spite of the case where a large perturbation occurs on the transmission line or there is a small perturbation to mechanical power inputs, the proposed controller can not only keep the system transiently stable but also simultaneously accomplish better dynamic properties of the system as compared to operation with the existing controllers designed through a coordinated passivation technique controller and a feedback linearization scheme, respectively.

Transient Stability Enhancement of a Wind Energy Distributed Generation System by Using Fuzzy Logic Stabilizers

2012 ◽  
Vol 36 (6) ◽  
pp. 687-700 ◽  
Author(s):  
M. A. Ebrahim ◽  
K. A. El-Metwally ◽  
F. M. Bendary ◽  
W. M. Mansour
Keyword(s):  
Power System ◽  
Wind Energy ◽  
Wind Turbine ◽  
Distributed Generation ◽  
Transient Stability ◽  
Synchronous Generator ◽  
Large Power ◽  
System Stabilizer ◽  
Stability Enhancement ◽  
Operating Points

This paper proposes a new power system stabilizer based on fuzzy systems. The new controller is applied to a wind turbine generating system comprising of a wind turbine driving a 3 - phase synchronous generator connected to a large power system. The new controller significantly improves system performance. The enhancement in the dynamic response of the system is verified through simulation results of a system under different operating points and exposed to both small and large disturbances. Extension to the wind energy distributed generation based multi-machine case is also included to illustrate the effectiveness of the proposed stabilizer in damping power system swing mode oscillations that follow disturbances.

scholarly journals Transient Stability Improvement of IEEE 9-Bus System Using Static Var Compensator

2021 ◽  
Vol 4 (4) ◽  
pp. 98-102
Author(s):  
Manish Shrivastava ◽  
Vinay Prakash ◽  
Vishal Kaushik ◽  
Vivek Kumar Upadhyay
Keyword(s):  
Power Systems ◽  
Transient Stability ◽  
Reactive Power ◽  
Test System ◽  
Limiting Factor ◽  
Static Var Compensator ◽  
Voltage Profile ◽  
Matlab Simulation ◽  
The Stability ◽  
Stability Limits

With increase in power demand over the last few decades, there has been a great expansion in power generation & transmission. But due to various disturbances, improper loading and environmental conditions the power systems are working near their stability limits which have become a power-transfer limiting factor. This in turn poses a threat to the stability of the system. Transient stability has been considered as one of the most important stability for a power system. In this paper Static VAR Compensator (SVC) has been discussed for reactive power control and hence improvement of transient stability and voltage profile. This paper incorporates IEEE-9 BUS test system with SVC controller using MATLAB Simulation.

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