Stability analysis of a generator excitation control system with time delays

2009 ◽  
Vol 91 (6) ◽  
pp. 347-355 ◽  
Author(s):  
Saffet Ayasun ◽  
Ayetül Gelen
Keyword(s):  
Control System ◽  
Stability Analysis ◽  
Time Delays ◽  
Excitation Control ◽  
Generator Excitation Control

scholarly journals Computation of Stability Delay Margin of Time-Delayed Generator Excitation Control System with a Stabilizing Transformer

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Saffet Ayasun ◽  
Ulaş Eminoğlu ◽  
Şahin Sönmez
Keyword(s):  
Control System ◽  
Time Delay ◽  
Characteristic Equation ◽  
Time Delays ◽  
System Stability ◽  
Imaginary Root ◽  
Excitation Control ◽  
Wide Range ◽  
Generator Excitation Control ◽  
Delay Margin

This paper investigates the effect of time delays on the stability of a generator excitation control system compensated with a stabilizing transformer known as rate feedback stabilizer to damp out oscillations. The time delays are due to the use of measurement devices and communication links for data transfer. An analytical method is presented to compute the delay margin for stability. The delay margin is the maximum amount of time delay that the system can tolerate before it becomes unstable. First, without using any approximation, the transcendental characteristic equation is converted into a polynomial without the transcendentality such that its real roots coincide with the imaginary roots of the characteristic equation exactly. The resulting polynomial also enables us to easily determine the delay dependency of the system stability and the sensitivities of crossing roots with respect to the time delay. Then, an expression in terms of system parameters and imaginary root of the characteristic equation is derived for computing the delay margin. Theoretical delay margins are computed for a wide range of controller gains and their accuracy is verified by performing simulation studies. Results indicate that the addition of a stabilizing transformer to the excitation system increases the delay margin and improves the system damping significantly.

scholarly journals Adaptive Dynamic Surface Control for Generator Excitation Control System

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Zhang Xiu-yu ◽  
Liu Cui-ping ◽  
Wang Jian-guo ◽  
Lin Yan
Keyword(s):  
Neural Network ◽  
Control System ◽  
Tracking Error ◽  
Dynamic Surface Control ◽  
Excitation Control ◽  
Dynamic Surface ◽  
Adaptive Dynamic ◽  
Surface Control ◽  
Control Scheme ◽  
Generator Excitation Control

For the generator excitation control system which is equipped with static var compensator (SVC) and unknown parameters, a novel adaptive dynamic surface control scheme is proposed based on neural network and tracking error transformed function with the following features: (1) the transformation of the excitation generator model to the linear systems is omitted; (2) the prespecified performance of the tracking error can be guaranteed by combining with the tracking error transformed function; (3) the computational burden is greatly reduced by estimating the norm of the weighted vector of neural network instead of the weighted vector itself; therefore, it is more suitable for the real time control; and (4) the explosion of complicity problem inherent in the backstepping control can be eliminated. It is proved that the new scheme can make the system semiglobally uniformly ultimately bounded. Simulation results show the effectiveness of this control scheme.

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