Method For Transient Stability Assessment Research Articles

A NOISE EQUIVALENT BANDWIDTH APPROACH TO OBTAIN REDUCED ORDER MODELS FOR POWER SYSTEM EXCITATION CONTROL

ABSTRACT In this paper the concept of noise equivalent bandwidth is used to obtain reduced order models of power system excitation control over a specified frequency range. The criteria for measuring the efficacy of the reduced model, consists of maintaining the fidelity of the dynamic behavior of the system variables in time domain. For this reason the performance of the reduced model is compared with that of the exact model via simulation on a 3-machine power system. The reduced order models are used when excitation control is incorporated in the transient energy function method of direct transient stability assessment of power systems [1 Fouad , A. A. , Vittal , V. , et al., “Direct Transient Stability Assessment With Excitation Control,” IEEE-PES Summer Meeting , Paper No. SP88-47 , July 1988 . [Google Scholar]]. The reduced order models provide a fairly accurate representation of the detailed models and reduce computational burden. This feature of the reduced order models is of significance in on-line security analysis of power systems.

A comparison of dynamic security indices based on direct methods

This paper presents a comparison of direct methods for transient stability assessment. The emphasis is on stability criteria based on Lyapunov's direct method. The comparison is made by studying the similarities and differences in the regions of attraction which the direct methods define. The region of attraction is characterized in terms of a performance index (PI) and a threshold value (TH). This paper reformulates the various Lyapunov energy functions and stability criteria for the direct methods proposed in the literature in a unified mathematical notation. Specifically, each energy function is reformulated in terms of a general form of the PI and each type of stability criterion is restated in terms of a threshold value, TH. Comparison tables are presented to identify the similarities and differences in the PI parameters, threshold values and dynamic models. These tables are used to show the correctness of several relationships among the direct methods mentioned in the literature and to derive new relationships for the similarities and differences between the direct methods.

A simple direct method for fast transient stability assessment of large power systems

A method for online transient stability assessment of large power systems is proposed. It consists of: replacing the multimachine system by a two-machine dynamic equivalent, further amenable to a one-machine-infinite-bus system; reducing the stability problem to a sole algebraic equation, devised from the equal area criterion, or equivalently from the Lyapunov direct criterion; and using this equation to derive one-shot stability analysis strategies. A technique for system admittance matrix reduction is developed that proves efficient, especially for large systems and multiple-contingency evaluation. The method's main appeal is rapidity: it is about one order of magnitude faster than the most efficient direct criterion. Other attractive features are flexibility and ability to encompass various simulation conditions. Extensions to online sensitivity analysis and control are suggested.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Fast methods for direct assessment of power system transient stability

The paper presents a new and simple method for transient stability assessment of multimachine power systems. The criterion for assessment is given in terms of the rate of change of kinetic energy of individual machines subsequent to fault clearance. The basic concepts and the mathematical formulation of the method are summarised. A number of practical test systems are used to demonstrate the superior efficiency of the method relative to three different Lyapunov functions given in the literature.

On-Line Secure-Economy Preventive Control of Power Systems by Pattern Recognition

A fast transient stability assessment method and a preventive control strategy, considering both security and economy of power systems, are presented. The pattern recognition approach with two dimensional feature space is used to assess transient security. If a power system is said to be in an alert state, then quick and appropriate control actions are required. A transient security constrained economic load dispatch (ELD) which is able to shift generator outputs so that system security can be maintained, is developed. The effectiveness of the proposed method is ascertained through numerical examples for model power systems.

On-Line Secure-Economy Preventive Control of Power Systems by Pattern Recognition

A fast transient stability assessment method and a preventive control strategy, considering both security and economy of power systems, are presented. The pattern recognition approach with two dimensional feature space is used to assess transient security. If a power system is said to be in an alert state, then quick and appropriate control actions are required. A transient security constrained economic load dispatch(ELD) which is able to shift generator outputs so that system security can be maintained, is developed. The effectiveness of the proposed method is ascertained through numerical examples for model power systems.

Methods for on-line transient stability assessment of power system

Methods for on-line transient stability assessment of power system

電力系統のオンライン過渡安定度評価手法

電力系統のオンライン過渡安定度評価手法