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.

Stability of Uncertain Linear Systems With Time Delay

1991 ◽  
Vol 113 (4) ◽  
pp. 558-567 ◽  
Author(s):  
K. Youcef-Toumi ◽  
J. Bobbett
Keyword(s):  
Time Delay ◽  
Linear Time ◽  
Sufficient Condition ◽  
Single Input Single Output ◽  
Time Delay Control ◽  
Linear Time Invariant ◽  
Single Output ◽  
Uncertain Dynamics ◽  
Delay Control ◽  
The Stability

The control of systems with uncertain dynamics and unpredictable disturbances has raised some challenging problems. This is particularly important when high system performance is to be guaranteed at all times. Recently, Time Delay Control has been suggested as an alternative control scheme. The proposed control system does not require an explicit plant model nor does it depend on the estimation of specific plant parameters. Rather, it combines adaptation with past observations to directly estimate the effect of the plant dynamics. This paper outlines the Time Delay Control law for a class of linear dynamic systems and then presents a sufficient condition for stability of linear uncertain systems with time delay. The ideas of Nyquist and Kharitonov are used in the development of a sufficient condition, which does not resort to using approximations for time delay. Like Nyquist, the condition depends on maps of the Nyquist path and, like Kharitonov, stability depends on four functions each yielding a stable system. In this paper we combine these ideas to determine the stability of systems where the Time Delay Controller is applied to single input single output, linear time-invariant plants whose coefficients are known to vary within certain defined intervals. The development is carried out in the context of Time Delay Control but it can be applied in more general cases. Two examples will illustrate the approach and the usefulness of the technique.

Active Vibration Suppression With Time Delayed Feedback

2003 ◽  
Vol 125 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Rifat Sipahi ◽  
Nejat Olgac
Keyword(s):  
Stability Analysis ◽  
Time Delay ◽  
Vibration Suppression ◽  
Linear Time ◽  
Direct Method ◽  
System Stability ◽  
Delayed Systems ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
The Stability

Various active vibration suppression techniques, which use feedback control, are implemented on the structures. In real application, time delay can not be avoided especially in the feedback line of the actively controlled systems. The effects of the delay have to be thoroughly understood from the perspective of system stability and the performance of the controlled system. Often used control laws are developed without taking the delay into account. They fulfill the design requirements when free of delay. As unavoidable delay appears, however, the performance of the control changes. This work addresses the stability analysis of such dynamics as the control law remains unchanged but carries the effect of feedback time-delay, which can be varied. For this stability analysis along the delay axis, we follow up a recent methodology of the authors, the Direct Method (DM), which offers a unique and unprecedented treatment of a general class of linear time invariant time delayed systems (LTI-TDS). We discuss the underlying features and the highlights of the method briefly. Over an example vibration suppression setting we declare the stability intervals of the dynamics in time delay space using the DM. Having assessed the stability, we then look at the frequency response characteristics of the system as performance indications.

scholarly journals Stability Problem of Wave Variable Based Bilateral Control: Influence of the Force Source Design

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
Dapeng Tian ◽  
Bao Zhang ◽  
Honghai Shen ◽  
Jiaquan Li
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Time Delay ◽  
Robust Stability ◽  
Scattering Theory ◽  
Stability Problem ◽  
Bilateral Control ◽  
Wave Variable ◽  
Small Gain ◽  
The Stability

The wave variable has been proposed to achieve robust stability against the time delay in bilateral control system. However, the influence of the force source on the overall system is still not clear. This paper analyzes this problem and proposes a supplement to the stability analysis for wave variable based bilateral control. Based on the scattering theory, it is pointed out that the design of force source decides the passivity of the two-port network of slave robot. This passivity influences the stability of overall system. Based on the characteristic equation and small gain theorem, it is clear that inappropriate designed force source in encoding the wave variable destroys the stability in the presence of time delay. A wave domain filter makes up for the broken stability. The principle of this reparation is explained in this paper. A reference is also provided by the analysis to design the parameter of the wave domain filter. Experiments prove the correctness and validity.

The Stability Conditions Evaluation of Network Control System Based on Double Time Delay Discrete Model

2013 ◽  
Vol 846-847 ◽  
pp. 112-115
Author(s):  
Ling Ding ◽  
Ping Fan ◽  
Bin Wen
Keyword(s):  
Control System ◽  
Time Delay ◽  
Control Systems ◽  
Discrete Model ◽  
Network Control ◽  
System Stability ◽  
Stability Conditions ◽  
Network Control System ◽  
Network Control Systems ◽  
The Stability

The current study of network control stability system has become a very hot topic, the stability conditions of network control systems have also carried out the relevant research on double delay discrete model, its main target to the current actual situation, which carries out the related stability for network control systems with state time-delay. This paper uses the relevant stability theory, the sufficient condition of network control system stability are described under the time-delay discrete model, on the basis of relevant transformation, completing the evaluation for the network control system stability condition of double delay discrete model. Finally, through the relevant data, to carry on its effectiveness validated. The method has certain reference significance for the stability study of similar system, and provides a theoretical reference for the research on this problem.

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.

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.

Complementary Sensitivity Design of PID Controllers for Arbitrary-Order Transfer Functions With Time Delay

2008 ◽  
Author(s):  
Tooran Emami ◽  
John M. Watkins
Keyword(s):  
Time Delay ◽  
Transfer Functions ◽  
Linear Time ◽  
Order System ◽  
Pid Controllers ◽  
Single Input Single Output ◽  
Linear Time Invariant ◽  
Single Output ◽  
Plant Transfer ◽  
Time Invariant

A graphical technique for finding all proportional integral derivative (PID) controllers that stabilize a given single-input-single-output (SISO) linear time-invariant (LTI) system of any order system with time delay has been solved. In this paper a method is introduced that finds all PID controllers that also satisfy an H∞ complementary sensitivity constraint. This problem can be solved by finding all PID controllers that simultaneously stabilize the closed-loop characteristic polynomial and satisfy constraints defined by a set of related complex polynomials. A key advantage of this procedure is the fact that it does not require the plant transfer function, only its frequency response.

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