In this paper we focus on the nonlinear behavior of the F coil current amplifier at the Frascati Tokamak Upgrade (FTU), which induces closed-loop instability of the horizontal position stabilizing loop whenever the requested current is below a minimum current level. In the paper we first illustrate a modeling phase where nonlinear dynamics are derived and identified to reproduce the open-loop responses measured by the F coil current amplifier. Based on this dynamic model, we then reproduce the closed-loop scenario of the experiment and show that the proposed nonlinear model successfully reproduces the instabilities experienced in the experimental sessions. Next we propose a nonlinear control solution to this instability problem inspired by the so-called anti-windup paradigm. We report on experiments carried out at FTU, testing two versions of the anti-windup solution differing in terms of performance and robustness.

An anti-windup-based solution for the low current nonlinearity compensation on the FTU horizontal position controller

Zaccarian, Luca
2010-01-01

Abstract

In this paper we focus on the nonlinear behavior of the F coil current amplifier at the Frascati Tokamak Upgrade (FTU), which induces closed-loop instability of the horizontal position stabilizing loop whenever the requested current is below a minimum current level. In the paper we first illustrate a modeling phase where nonlinear dynamics are derived and identified to reproduce the open-loop responses measured by the F coil current amplifier. Based on this dynamic model, we then reproduce the closed-loop scenario of the experiment and show that the proposed nonlinear model successfully reproduces the instabilities experienced in the experimental sessions. Next we propose a nonlinear control solution to this instability problem inspired by the so-called anti-windup paradigm. We report on experiments carried out at FTU, testing two versions of the anti-windup solution differing in terms of performance and robustness.
IEEE Conference on Decision and Control
USA
IEEE-CSS
R., Vitelli; L., Boncagni; F., Mecocci; S., Podda; V., Vitale; Zaccarian, Luca
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/67119
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 3
social impact