Dynamic Stability of Long Transmission Systems with Static Compensators and Synchronous Machines
TL;DR: In this article, the static compensator and the excitation system control parameters are chosen in a coordinated manner from the stability limit plots, the extension of stability limits with a Static Compensator are quantised, later a second compensator is included for improving the system performance.
Abstract: This paper deals with the dynamic stability of long distance a.c. transmission systems operating at above 1 surge impedance loading and compensated entirely by automatically controlled shunt inductance device referred to as Static Compensators. Generalised system equations in the form X = AX, with a careful choice of state variables are developed via the subsystem concept and the eigenvalue technique used to establish the stability limits. The static compensator and the excitation system control parameters are chosen in a coordinated manner from the stability limit plots, the extension of stability limits with a Static Compensator are quantised, later a second compensator is included for improving the system performance and interaction studies.
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Book•
01 Jan 2001
TL;DR: This book discusses the design Principles of Single-Input Single-Output Nonlinear Control Systems and their applications in Electric Power Systems and Nonlinear Excitation Control of Large Synchronous Generators.
Abstract: Preface. 1. Introduction. 2. Basic Concepts of Nonlinear Control Theory. 3. Design Principles of Single-Input Single-Output Nonlinear Control Systems. 4. Design Principles of Multi-Input Multi-Output Nonlinear Control Systems. 5. Basic Mathematical Descriptions for Electric Power Systems. 6. Nonlinear Excitation Control of Large Synchronous Generators. 7. Nonlinear Steam Valving Control. 8. Nonlinear Control of HVDC Systems. 9. Nonlinear Control of Static Var Systems. 10. Nonlinear Robust Control of Power Systems. Index.
258Â citations
TL;DR: The application of superconducting magnet energy storage (SMES) to the stabilization of a power system with long-distance bulk power transmission lines which has the problem of poorly damped power oscillations is presented in this paper.
Abstract: The application of superconducting magnet energy storage (SMES) to the stabilization of a power system with long-distance bulk power transmission lines which has the problem of poorly damped power oscillations is presented. Control schemes for stabilization using SMES capable of controlling active and reactive power simultaneously in four quadrant ranges are proposed. The effective locations and the necessary capacities of SMES for power-system-stabilizing control are discussed in detail. Results of numerical analysis and experiments in an artificial power-transmission system demonstrate the significant effect of the control by SMES on the improvement of power-system oscillatory performance. >
203Â citations
TL;DR: In this article, the design of a static voltampere reactive (VAr) controller using a novel adaptive scheme is investigated, which makes use of self-tuning proportional-integral-derivative (PID) control, can provide better damping characteristics than a fixed-gain PID control SVC over a wide range of operating conditions.
Abstract: Design of a static voltampere reactive (VAr) controller (SVC) using a novel adaptive scheme is investigated. The proposed controller, which makes use of self-tuning proportional-integral-derivative (PID) control, can provide better damping characteristics than a fixed-gain PID control SVC over a wide range of operating conditions. The system considered is a synchronous generator connected to an infinite bus through a double circuit transmission line. Digital simulations of the system following a three-phase fault under different loading conditions were performed to demonstrate the robustness and effectiveness of the controller. >
87Â citations
TL;DR: In this article, a comparative study on the application of two countermeasures, i.e., the excitation controller and the static VAr compensator (SVC), for damping of subsynchronous resonance (SSR) is presented.
Abstract: The results of a comparative study on the application of two countermeasures, i.e. the excitation controller and the static VAr compensator (SVC), for damping of subsynchronous resonance (SSR) are presented. To stabilize all the SSR modes, a unified approach based on modal control theory is proposed for the design of the excitation controller and the SVC, which are essentially dynamic output feedback compensators. The two damping schemes differ in the way they modulate the reactive power flow in the system to damp out the subsynchronous oscillations. To demonstrate the effectiveness of the proposed damping schemes under disturbance conditions, time-domain simulations based on a nonlinear system model are also performed. The relative merits of the two countermeasures are compared with respect to their validities under various loading conditions and different degrees of series compensations and their capabilities to expand the stable region on the real-capacitive reactance plane. >
60Â citations
TL;DR: In this article, a comparative study of the application of three different compensators, the power system stabilizer (PSS), the static VAR compensator (SVC), and the rectifier current regulator (RCR), for the damping enhancement of generator oscillations in a power system is presented.
Abstract: Results of a comparative study of the application of three different compensators, the power system stabilizer (PSS), the static VAR compensator (SVC), and the rectifier current regulator (RCR), for the damping enhancement of generator oscillations in a power system are presented. In order to enhance the dampings of both the mechanical mode and the exciter mode in the system, a unified approach based on modal control theory is proposed for the design of the PSS, the SVC, and the RCR. A proportional-integral-derivative (PID) type controller using generator speed deviation as a modulated signal to generate the desired damping is proposed, and it is shown that both affected system modes can be exactly located at the prespecified positions on the complex plane by the proposed damping schemes. To demonstrate the effectiveness of the proposed PID controllers and their relative merits, a frequency-domain study based on eigenvalue analysis under different operating conditions and a time-domain study based on nonlinear model simulations under disturbance conditions are performed. >
40Â citations
References
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TL;DR: In this paper, the authors describe the small signal performance of a multi-machine synchronous power system by a set of differential equations of the form [x] = [A] [x], allowing standard multivariable control theory to be used in dynamic stability studies.
Abstract: Describing the small signal performance of a multi- machine synchronous power system by a set of differential equations of the form [x] = [A] [x] allows standard multivariable control theory to be used in dynamic stability studies. The construction of the [A] matrix for a multimachine power system involves the application of Kron's rotational transformation to the transmission network admittance matrix, and a matrix analysis of the synchronous machines using internal flux linkages as state variables.
140Â citations
01 Feb 1966
TL;DR: In this paper, a set of general coefficients related to the well known Heffron and Phillips constants is derived by means of matrix algebra, which allows complex impedance terms to be included in the analysis.
Abstract: The design of synchronous-generator automatic regulating equipment by linearisation techniques is now firmly established. The paper presents an obvious extension of one method, where, by means of matrix algebra, a set of general coefficients related to the well known Heffron and Phillips constants is derived, which allows complex impedance terms to be included in the analysis. In keeping with modern practice, these constants are incorporated in equations which are formulated as sets of first-order differential equations. This form provides a basis for future applications of optimal control theory, and, in addition, may be scaled more easily in both time and amplitude for analogue-simulation studies. A detailed example of a multiloop a.v.r. connected to a 30MW machine is given for reference purposes. The matrix methods, used in conjunction with the matrix iterative techniques of load-flow analysis, extend naturally to multimachine systems, allowing the dynamic operating and stability problem to be investigated with respect to possible future multimachine co-ordinated control schemes.
71Â citations
TL;DR: In this paper, a digital computer method for obtaining eigenvalue sensitivities of interconnected power systems is presented, especially suited to the analysis of detailed modelled synchronous machine systems where shaft and stator-network dynamic effects are significant.
Abstract: A practical digital computer method for obtaining eigenvalue sensitivities of interconnected power systems is presented. The method is especially suited to the analysis of detailed modelled synchronous machine systems where shaft and stator-network dynamic effects are significant. A unified structure in the construction of the state space equations permits the inclusion of a wide variety of control equipment and varying degrees of modelling complexity. Sample results are given for typical cases illustrating the significance of eigenvalue sensitivities. Specifically results are presented for a 4 generator hydroelectric system and for a 2 generator system exibiting subsynchronous torsional resonance.
47Â citations
01 Jun 1966
TL;DR: In this article, a detailed study of the effect of a voltage regulator on the stability of an alternator connected through a reactance to an infinite bus is performed, and the stability is analyzed by means of Nyquist loci calculated for the transfer functions of alternator and regulator.
Abstract: The paper records a detailed study of the effect of a voltage regulator on the stability of an alternator connected through a reactance to an infinite bus. The stability is analysed by means of Nyquist loci calculated for the transfer functions of alternator and regulator. The accuracy and speed of response of the system are also considered. The first part of the paper considers a simple regulator with proportional feedback, and it is shown that such an ideal regulator can extend the region of steady-state stability to a point corresponding to the maximum of the transient power-angle curve. Practical regulators are classified according to the nature of their transfer functions. The analysis provides a means of predicting their behaviour and explains how they affect the stability, accuracy and response. The effect of delay elements, integrator elements and derivative elements in the regulator is considered particularly; e.g. a buck-boost exciter, which effectively introduces an integrator element, gives good accuracy but less satisfactory response, and has a limited effect on stability, and a derivative regulator which gives rapid response and a large extension of the stability region, but has limited accuracy. Experiments performed on a model machine with various simulated regulators agreed well with the computed results. The computations allowed fully for the system parameters, including alternator resistance and alternator damping.
35Â citations
01 Jan 1978
28Â citations