scholarly journals Transient Stability Analysis of a Transmission Network Using Eigenvalue Principles with Automated VAR Compensation: A Case Study of the Nigerian Eastern Grid

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5289
Author(s):  
Ewaoche John Okampo ◽  
Nnamdi Nwulu ◽  
Pitshou N. Bokoro
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Transient Stability ◽  
System Stability ◽  
Step Response ◽  
Actual State ◽  
Transmission Network ◽  
Seamless Integration ◽  
Guarantee System ◽  
The Stability

Power systems may encounter disturbances during operation as a result of switching of various components, etc. Such perturbations include transformer tap-changing action, load variations, and line outages due to various types of faults of which an earth fault is the most common. Stability analysis of a transmission system is necessary for us to determine the stability state of the system so that appropriate control measures can be implemented to guarantee system stability. This article presents the use of eigenvalue obtained from the system-linearized eigenvectors to analyze the stability state of the system. The choice of the eigenvalue principle is based on the strength of accuracy of the method to determine the actual state of the system providing adequate data for easy solution to the problem. The node admittance parameters computed from the line parameters is applied to the eigenvalue–eigenvector model to determine the system stability state. The state of the eigenvalue is used as an input to a control system, which utilized static volt-ampere reactive (VAR) compensators (SVC) to automatically stabilize the non-stable buses in the transmission network. The 6 × 6 nodal admittance matrix is formed and fed to the developed eigenvalue–eigenvector model via MATLAB in order to compute the right and left eigenvectors and the diagonal or eigenvalue of the network under steady-state and contingency condition. After this, the system stability state is determined, and necessary control actions by the SVC are implemented to guarantee system security. The developed model was tested on the 6 bus Eastern Grid Nigerian Transmission Network and validated using a 41 bus network of the same country. The compensated model showed considerable efficiency in improving the transient stability state of the transmission networks in terms of ease of operation, seamless integration into existing control system, and efficient utilization of SVS to compensate for reactive power imbalances. The results from the step response graph of the compensated model shows performance accuracy as the system regained stability in less than 0.5 s, which is a significant improvement over the uncompensated model.

scholarly journals Rotation Modes Stability Analysis and Phase Compensation for Magnetically Suspended Flywheel Systems with Cross Feedback Controller and Time Delay

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yuan Ren ◽  
Xiaocen Chen ◽  
Yuanwen Cai ◽  
Weijie Wang
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Time Delay ◽  
System Stability ◽  
Complex Coefficient ◽  
Phase Compensation ◽  
Single Input Single Output ◽  
Single Output ◽  
The Stability ◽  
Gyroscopic Effects

This paper analyzes the effects of time delay on the stability of the rotation modes for the magnetically suspended flywheel (MSFW) with strong gyroscopic effects. A multi-input multioutput system is converted into a single-input single-output control system with complex coefficient by variable reconstruction, and the stability equivalence of the systems before and after variable reconstruction is proven. For the rotation modes, the stability limits and corresponding vibration frequencies are found as a function of nondimensional magnetic stiffness and damping and nondimensional parameters of rotor speed and time delay. Additionally, the relationship between cross feedback control system stability and time delay is investigated. And an effective phase compensation method based on cross-channel is further presented. Simulation and experimental results are presented to demonstrate the correctness of the stability analysis method and the superiority of the phase compensation strategy.

The Application of LabVIEW in Control System Stability Analysis

2012 ◽  
Vol 182-183 ◽  
pp. 788-792
Author(s):  
Xue Ning Xing
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
User Interface ◽  
Control Theory ◽  
Time Domain ◽  
System Stability ◽  
Graphic User Interface ◽  
System Stability Analysis ◽  
The Stability ◽  
Classical Control

The stability of the system is the prior condition for whether the control system can operate normally, in the classical control theory, time domain analyze method, complex domain analyze method and frequency domain analyze method are often used to analyze the performance of the control system. Using LabVIEW to design graphic user interface, input parameters, then the curve can be drawn out immediately and calculate the interrelated parameters, which plays an important role in analyzing the stability of the system.

scholarly journals Research of Mapping Element Space Method for Uncertain Lurie System Stability Diagnosis

2019 ◽  
Vol 37 (5) ◽  
pp. 952-961
Author(s):  
Weijun Hu ◽  
Yiming Ma ◽  
Jun Zhou
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Flight Control ◽  
Time Series Data ◽  
System Stability ◽  
Series Data ◽  
Discrete Equation ◽  
Linear Matrix ◽  
Flight Control System ◽  
The Stability

A new diagnosis method of Lurie system stability by using Chaotic time series data was proposed in order to solve stability analysis of flight control system with fault and uncertain. Firstly, the reasons for the instability of the nonlinear system of Ruri leaf was analyzed by using the small gain theory and linear matrix inequalities in the robust control theory. And the stability conditions of Rui leaf system under the condition of uncertainty and failure were proved theoretically. In order to quantify the stability of nonlinear systems in complex Ruri leaves, based on the theory of phase space reconstruction, the nonlinear Ruri system with continuous discrete characteristics was converted into an approximate time discrete equation, mapping it to a low dimensional primitive space, by introducing Q Gauss function into Kernel function, the generalization ability of neural networks are enhanced, realizing the stability analysis method based on the characteristic of primitive migration, which is suitable for various fault and uncertainty conditions, and the relative quantized stability norm can be given. The simulation shows that the present method can effectively solve the stability analysis and determination of flight control system under various factors.

scholarly journals Desain dan analisis pengaruh parameter PI dan variasi kecepatan pada respon sistem kontrol arah hadap prototype kendaraan listrik

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Afif Caesar Distara ◽  
Fatkhur Rohman
Keyword(s):  
Control System ◽  
Steady State ◽  
Electric Vehicles ◽  
Rise Time ◽  
Small Error ◽  
Settling Time ◽  
System Stability ◽  
Prototype System ◽  
Stability Parameters ◽  
The Stability

Electric vehicles are alternative vehicles that carry energy efficient. At this time the dominant vehicle uses ordinary wheels so that it will become an obstacle in the maneuver function that requires movement in various directions. With mechanum wheels the vehicle can move in various directions by adjusting the direction of rotation of each wheel. The problem is choosing the right control system for the control system needed by the vehicle. The purpose of this study is to determine and analyze the effect of variations in the value of PI (Proportional Integral) and speed of the vehicle to the stability response of the system to control the direction of prototype electric vehicles. This study method is an experiment that is by giving a treatment, then evaluating the effects caused by the research object. The results of this study can be concluded that the variation of PI constant values and speed variations have an effect on the stability parameters of the system, namely rise time, settling time, overshot, and steady state error. To get the best system stability response results can use the constant value PI Kp = 2; and Ki = 17; where the stability response of the system for direction control at each speed condition has a fairly good value with a fast rise time, fast settling time, small overshot and a small error steady state compared to other PI constant values in this study.Keywords: mechanum wheel, PI control, direction, prototype, system stability

scholarly journals BUNDLE ADJUSTMENT-BASED STABILITY ANALYSIS METHOD WITH A CASE STUDY OF A DUAL FLUOROSCOPY IMAGING SYSTEM

2018 ◽  
Vol IV-2 ◽  
pp. 9-16 ◽  
Author(s):  
K. Al-Durgham ◽  
D. D. Lichti ◽  
I. Detchev ◽  
G. Kuntze ◽  
J. L. Ronsky
Keyword(s):  
Stability Analysis ◽  
Imaging System ◽  
Parameters Estimation ◽  
System Stability ◽  
Single Camera ◽  
Calibration Data ◽  
Analysis Method ◽  
Advantages And Disadvantages ◽  
Camera Imaging ◽  
The Stability

A fundamental task in photogrammetry is the temporal stability analysis of a camera/imaging-system’s calibration parameters. This is essential to validate the repeatability of the parameters’ estimation, to detect any behavioural changes in the camera/imaging system and to ensure precise photogrammetric products. Many stability analysis methods exist in the photogrammetric literature; each one has different methodological bases, and advantages and disadvantages. This paper presents a simple and rigorous stability analysis method that can be straightforwardly implemented for a single camera or an imaging system with multiple cameras. The basic collinearity model is used to capture differences between two calibration datasets, and to establish the stability analysis methodology. Geometric simulation is used as a tool to derive image and object space scenarios. Experiments were performed on real calibration datasets from a dual fluoroscopy (DF; X-ray-based) imaging system. The calibration data consisted of hundreds of images and thousands of image observations from six temporal points over a two-day period for a precise evaluation of the DF system stability. The stability of the DF system – for a single camera analysis – was found to be within a range of 0.01 to 0.66 mm in terms of 3D coordinates root-mean-square-error (RMSE), and 0.07 to 0.19 mm for dual cameras analysis. It is to the authors’ best knowledge that this work is the first to address the topic of DF stability analysis.

Non-Linear Transient Stability Analysis of a Rigid Rotor Supported on Journal Bearings With Rectangular Dimples

2015 ◽  
Author(s):  
Ram Turaga
Keyword(s):  
Stability Analysis ◽  
Surface Texture ◽  
Transient Stability ◽  
Equations Of Motion ◽  
Journal Bearings ◽  
Pressure Curve ◽  
Rigid Rotor ◽  
Non Linear ◽  
The Stability ◽  
Transient Stability Analysis

The influence of deterministic surface texture on the sub-synchronous whirl stability of a rigid rotor has been studied. Non-linear transient stability analysis has been performed to study the stability of a rigid rotor supported on two symmetric journal bearings with a rectangular dimple of large aspect ratio. The surface texture parameters considered are dimple depth to minimum film thickness ratio and the location of the dimple on the bearing surface. Journal bearings of different Length to diameter ratios have been studied. The governing Reynolds equation for finite journal bearings with incompressible fluid has been solved using the Finite Element Method under isothermal conditions. The trajectories of the journal center have been obtained by solving the equations of motion of the journal center by the fourth-order Runge-Kutta method. When the dimple is located in the raising part of the pressure curve the positive rectangular dimple is seen to decrease the stability whereas the negative rectangular dimple is seen to improve the stability of the rigid rotor.

scholarly journals Sliding mode learning control of uncertain nonlinear systems with Lyapunov stability analysis

2018 ◽  
Vol 41 (6) ◽  
pp. 1750-1760
Author(s):  
Erkan Kayacan
Keyword(s):  
Stability Analysis ◽  
Nonlinear Systems ◽  
Lyapunov Stability ◽  
Sliding Mode ◽  
Learning Control ◽  
System Stability ◽  
Uncertain Nonlinear Systems ◽  
System Behaviour ◽  
Lyapunov Stability Analysis ◽  
The Stability

This paper addresses the Sliding Mode Learning Control (SMLC) of uncertain nonlinear systems with Lyapunov stability analysis. In the control scheme, a conventional control term is used to provide the system stability in compact space while a type-2 neuro-fuzzy controller (T2NFC) learns system behaviour so that the T2NFC completely takes over overall control of the system in a very short time period. The stability of the sliding mode learning algorithm has been proven in the literature; however, it is restrictive for systems without overall system stability. To address this shortcoming, a novel control structure with a novel sliding surface is proposed in this paper, and the stability of the overall system is proven for nth-order uncertain nonlinear systems. To investigate the capability and effectiveness of the proposed learning and control algorithms, the simulation studies have been carried out under noisy conditions. The simulation results confirm that the developed SMLC algorithm can learn the system behaviour in the absence of any mathematical model knowledge and exhibit robust control performance against external disturbances.

The Analysis of the Systems Stability of Linear Differential Equations Based on the Transformation of Difference Schemes

2019 ◽  
Vol 20 (9) ◽  
pp. 542-549 ◽  
Author(s):  
S. G. Bulanov
Keyword(s):  
Stability Analysis ◽  
Asymptotic Stability ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Computer Analysis ◽  
Linear Differential Equations ◽  
System Stability ◽  
The Difference ◽  
Linear Differential ◽  
The Stability

The approach to the analysis of Lyapunov systems stability of linear ordinary differential equations based on multiplicative transformations of difference schemes of numerical integration is presented. As a result of transformations, the stability criteria in the form of necessary and sufficient conditions are formed. The criteria are invariant with respect to the right side of the system and do not require its transformation with respect to the difference scheme, the length of the gap and the step of the solution. A distinctive feature of the criteria is that they do not use the methods of the qualitative theory of differential equations. In particular, for the case of systems with a constant matrix of the coefficients it is not necessary to construct a characteristic polynomial and estimate the values of the characteristic numbers. When analyzing the system stability with variable matrix coefficients, it is not necessary to calculate the characteristic indicators. The varieties of criteria in an additive form are obtained, the stability analysis based on them being equivalent to the stability assessment based on the criteria in a multiplicative form. Under the conditions of a linear system stability (asymptotic stability) of differential equations, the criteria of the systems stability (asymptotic stability) of linear differential equations with a nonlinear additive are obtained. For the systems of nonlinear ordinary differential equations the scheme of stability analysis based on linearization is presented, which is directly related to the solution under study. The scheme is constructed under the assumption that the solution stability of the system of a general form is equivalent to the stability of the linearized system in a sufficiently small neighborhood of the perturbation of the initial data. The matrix form of the criteria allows implementing them in the form of a cyclic program. The computer analysis is performed in real time and allows coming to an unambiguous conclusion about the nature of the system stability under study. On the basis of a numerical experiment, the acceptable range of the step variation of the difference method and the interval length of the difference solution within the boundaries of the reliability of the stability analysis is established. The approach based on the computer analysis of the systems stability of linear differential equations is rendered. Computer testing has shown the feasibility of using this approach in practice.

Modeling and Stability Analysis of Dynamic Control Through a Soft Interface

2006 ◽  
Vol 18 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Mizuho Shibata ◽  
◽  
Shinichi Hirai
Keyword(s):  
Stability Analysis ◽  
Discrete Time ◽  
Feedforward Control ◽  
Dynamic Control ◽  
System Stability ◽  
Critical Stability ◽  
Runge Kutta Method ◽  
The Stability ◽  
The Relationship ◽  
Soft Interface

To analyze the stability of dynamic control through asoft interface-the viscoelastic material between a manipulating finger and a manipulated object- we model dynamic control through the soft interface in continuous-discrete time. We then formulate dynamics using a modified z-transform in continuous-discrete time for feedback and feedforward control. We show that system stability depends on the viscoelasticity of the soft interface for feedback control. The relationship between material viscosity and sampling time in critical stability is not monotonous, a phenomenon we analyze by root locus. We compare stability analysis by the modified z-transform, simulations based on the Runge-Kutta method, and a regular z-transform, demonstrating that the relationship is specific to a continuous-discrete time.

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