Design of a new controller of MHD modes in RFX-mod

Anton Soppelsa, Giuseppe Marchiori, Lionello Marrelli, Paolo Zanca

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10 Citations (Scopus)


The RFX-mod machine is equipped with a powerful system for the active control of MHD modes. It consists of 192 active saddle coils and corresponding amplifiers, 192 × 3 magnetic field sensors and a number of passive structures. A control system designed following SISO techniques allowed to achieve a good quality of the static spatial spectrum, but its dynamic behavior was not completely satisfactory in meeting the requirements of tearing mode control. Thus, a new MIMO design procedure was started on the basis of an available and already validated MIMO full electromagnetic model, whose inputs and outputs are the coil currents and the radial field fluxes measured by the sensors, respectively. A dynamic compensator derived from the pseudo-inverse of the system transfer function matrix was designed and a decentralized controller was then implemented. Simulations of mode tracking and mode rejection at different frequencies were run to compare the performances of a SISO-based controller and the newly designed one. Satisfactory results were obtained showing the possibility of designing a controller able to equalise the spatial spectral dynamic response. These results are presented and commented in the paper. © 2008 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)224 - 227
Number of pages4
JournalFusion Engineering and Design
Issue number2-3
Publication statusPublished - Apr 2008
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Materials Science(all)
  • Nuclear Energy and Engineering
  • Mechanical Engineering

Cite this

Soppelsa, A., Marchiori, G., Marrelli, L., & Zanca, P. (2008). Design of a new controller of MHD modes in RFX-mod. Fusion Engineering and Design, 83(2-3), 224 - 227.