A fully modular tool for small-signal stability analysis of hydroelectric systems

Philippe Allenbach, Sébastien Alligné, Pedro Camilo de Oliveira e Silva, Basile Kawkabani
IEEE, 2014
Article de conférence

Résumé

In electrical systems, the small-signal stability analysis method is usually applied to synchronous machines by using the Park representation (d, q-components). This paper presents the generalization of a different approach for this method, based on a, b, c phase variables. This approach is essential to software systems using phase variables as state variables and its generalization yields a small-signal stability analysis tool which is fully modular. Two test cases are presented to showcase the application of this approach to elements such as synchronous machines, automatic voltage regulator (AVR), power system stabilizer of type IEEE PSS2B, penstock, Francis turbine and speed regulator.

Official source

https://infoscience.epfl.ch/record/255752?ln=fr

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Concepts associés

Chargement

Publications associées

Chargement

Methodology for Risk Assessment of Part Load Resonance in Francis Turbine Power Plant

Philippe Allenbach, François Avellan, Bob Greiveldinger, Christophe Nicolet, Jean-Jacques Simond

At low flow rate operation, Francis turbines feature a cavitating vortex rope in the draft tube resulting from the swirling flow of the runner outlet. The unsteady pressure field related to the precession of the vortex rope induces plane wave propagating in the entire hydraulic system. The frequency of the vortex rope precession being comprised between 0.2 and 0.4 times the turbine rotational speed, there is a risk of resonance between the hydraulic circuit, the synchronous machine and the turbine itself an acting as excitation source. This paper presents a systematic methodology for the assessment of the resonance risk for a given Francis turbine power plant. The test case investigated is a 1GW 4 Francis turbines power plant. The methodology is based on a transient simulation of the dynamic behavior of the whole power plant considering a 1D model of the hydraulic installation, comprising gallery, surge chamber, penstock, Francis turbine but also mechanical masses, synchronous machines, transformer, grid model, speed and voltage regulators. A stochastic excitation having energy uniformly distributed in the frequency range of interest is taken into account in the draft tube. As the vortex rope volume has a strong influence on the natural frequencies of the hydraulic system, the wave speed in the draft tube is considered as a parameter for the investigation. The transient simulation points out the key excitation frequencies and the draft tube wave speed producing resonance between the vortex rope excitation and the circuit and provide a good evaluation of the impact on power quality. The comparison with scale model tests results allows resonance risk assessment in the early stage of project pre-study.

2006

Chargement

, , , , ,

The eigenvalues analysis method is generally applied to synchronous machines by using d,q-components. This paper presents the application of this method on an equivalent model for the synchronous machine based on phase variables a,b,c instead of d,q-components. The advantages of this approach, essential for programs using phase variables as state variables, are presented. The application of this method to a complete hydroelectric production site including hydraulic components (pump-turbine, penstock, gallery, reservoir…), permits the study and analysis of the interactions between the hydraulic, electric and regulation parts of the system. Results coming from the proposed eigenvalues analysis method and the numerical simulations confirm the interest of the presented approach.

2010

Chargement

New Tools for the Simulation of Transient Phenomena in Francis Turbine Power Plants

Philippe Allenbach, François Avellan, Christophe Nicolet, Alain Sapin, Jean-Jacques Simond

An analytical approach allowing modelling transient phenomena in pipes, valves, surge tanks and Francis turbines based on impedance method is developed. These models are implemented in a software called “SIMSEN”, which simulates the behaviour of complex applications in the domain of adjustable speed drives and electrical power networks. This program is based on a modular structure, which enables the numerical simulation of transient modes of systems exhibiting arbitrary topologies. The numerical simulation for transient phenomena in hydropower plants with “SIMSEN” has the benefit of an algorithm that generates and solves an integrated set of differential equations. This algorithm solves simultaneously the electrical, hydraulic and control equations ensuring a proper interaction between the three parts of the system. The case of a Francis turbine power plant is studied. The model of the turbine is based on measured steady state characteristics. The simulation of the dynamic behaviour of the power plant under load variation is investigated

International Association For Hydraulic Research2002

Chargement