Eigenvalues analysis applied to the stability study of a variable speed pump turbine unit

Abstract

Abstract-This paper presents an eigenvalues analysis method for an induction machine model based on phase variables a,b,c. This approach is validated by comparison with a d,q approach and applied to a variable speed pump-turbine unit using a simplified model of the converters. The proposed approach permits the study and analysis of the interaction between mechanical, electric and regulation parts of the system. The study, modeling and analysis of the dynamic behavior of variable speed pump-turbine units have been presented and published in several papers in the last decade [6]- [15]. The aim of this study is to develop an analytical approach based on the eigenvalues analysis method in order to facilitate the study of the interactions between the hydraulic, electric and regulation parts of a variable speed pump-turbine unit, and to identify the origin of eventual instabilities. IndexA similar method has been applied efficiently to a complete hydroelectric production site with a synchronous generator by using a, b, c phase variables instead of d-q components [16].The advantage of the extension of the eigenvalue analysis method to a, b, c phase variables instead of d-q components is mainly the possibility of the application of this method to any symmetrical or asymmetrical mode of operation of the machine without specific additional developments. Moreover, most of developed software packages dedicated to the numerical simulation of power systems [17]

Stability Analysis of a Run-of-River Diversion Hydropower Plant with Surge Tank and Spillway in the Head Pond

“…In [ 24 ], the PID gains are analytically determined by pole placement; good performance was obtained in simulations and field tests conducted in a real plant. In [ 25 , 26 ], the stability study and the tuning of the PID were carried out by eigenvalues analysis; oscillation modes were identified and associated with the different elements of the power plant.…”