Participation Factor Analysis Research Articles

Evaluation of small signal stability of a power system

In reality, a power system is never in steady-state, as there are persistent fluctuations in load levels with associated adjustments in generation. The growing complexity of power systems, as well as the system exposition to various contingencies, have exacerbated the system's steady-state condition. Small disturbances that are always present in power system networks include small variations in loads, generation and switching operation of power system equipment. It is important to maintain the load-generation balance such that the system frequency remains nominal. Multiple severe contingencies with complex interaction would cause system instabilities, and thus deteriorate the system condition. This paper explores transient stability of a power system subjected to small disturbances using time domain analysis, eigen-values analysis, participation factors analysis, and transient security assessment using transient security index. Simulations have been conducted on the IEEE 14-bus system and the results presented.

Measuring Meaning in Life

The present studies addressed the need for a comprehensive, economical, and psychometrically adequate measure of existential meaning. In Study 1, principal-axis factor analysis of participants’ responses to popular meaning measures identified five latent constructs underlying them, labelled purposeful life, principled life, valued life, exciting life, and accomplished life. These dimensions resonate with the meaning in life concept as understood by Frankl (1963. Man’s search for meaning. (Revised Ed.) London: Hodder & Stoughton) and the panoply of subsequent theoretical definitions (e.g. Battista and Almond. (1973). Psychiatry, 36, 409–427; 2000. Exploring existential meaning: Optimising human development across the life span (pp. 39–55). USA: Sage; 1998. The human quest for meaning: A handbook of psychological research and clinical applications (pp. 11–140). Mahwah: Lawrence Erlbaum). Study 2 used these results as a foundation for developing a psychometrically satisfactory self-report questionnaire of each of these aspects of meaning in life. Confirmatory factor analysis (CFA) validated a five-factor structure, with each factor loading on a common second-order factor. Study 3 provided evidence for this new measure’s convergent validity and economic property. The final Meaningful Life Measure is reported and provides comprehensive but differentiated measurement of the meaning in life construct.

DESIGN OF VARIABLE STRUCTURE STABILIZER USING POLE ASSIGNMENT TECHNIQUE

ABSTRACT This paper gives a systematic approach in designing VS(Variable structure)stabilizer for excitation control problem of SMIB(Single Machine Infinite Bus) system. By observing the behaviour of variation of eigenvalues with respect to change of operating points,using participation factors analysis a tentative pole placement has been given such that switching plane obtained at a nominal operating point is valid over a wide range of operating points. This paper gives a computational procedure for determination of gains using the condition to be satisfied inorder that sliding takes place. The gains are determined in such a way that they guarantee sliding mode over a wide range of operating conditions. The performance of VS stabilizer is compared with Constant Gain Power system Stabilizer(CGPS) using feedback from all state variables of the system and conventional Power System Stabilizer(PSS) in the form of lead/lag blocks and reset block.

Analytical formulation of small signal stability analysis of power systems with nonlinear loads

It is now recognized that both load dynamics and generating unit dynamics contribute significantly to the limitation of loadability of power systems. In this paper, we take a static nonlinear load representation and different combinations of machine and exciter dynamic models to develop a comprehensive linearized model to study small signal stability. In particular we monitor the Hopf bifurcation instability and through participation factor analysis we identify the relevant state variables.

Analytical formulation of small signal stability analysis of power systems with nonlinear load models

It is now recognized that both load dynamics and generating unit dynamics contribute significantly to the limitation of loadability of power systems. In this paper, we take a static nonlinear load representation and different combinations of machine and exciter dynamic models to develop a comprehensive linearized model to study small signal stability. In particular we monitor the Hopf bifurcation instability and through participation factor analysis we identify the relevant state variables.

A New Pole-Placement Method for Excitation Control Design to Damp SSR of a Nonidentical Two-Machine System

A pole-placement method is developed for designing the excitation control of a multimode SSR (subsynchronous resonance) of the Second Benchmark Model, System 2. The system has two nonidentical turbine-generators closely coupled. The method uses signals selected from participation factor analysis for the local feedback. Both eigenvalue analysis and nonlinear simulation tests show that the control thus designed is very effective for controlling the multimode torsional oscillations of the system. Torsional interaction of the two closely coupled machines is also analyzed. >

A new pole-placement method for excitation control design to damp SSR of a nonidentical two-machine system

A pole-placement method is developed for designing the excitation control of a multimode SSR (subsynchronous resonance) of the Second Benchmark Model, System 2. The system has two nonidentical turbine-generators closely coupled. The method uses signals selected from participation factor analysis for the local feedback. Both eigenvalue analysis and nonlinear simulation tests show that the control thus designed is very effective for controlling the multimode torsional oscillations of the system. Torsional interaction of the two closely coupled machines is also analyzed. >