A van der Pol coupled-oscillator model as a basis for developing a system for suppressing MHD instabilities in a tokamak

Journal Article · Wed Feb 15 04:00:00 EST 2006 · Plasma Physics Reports

DOI:https://doi.org/10.1134/S1063780X0602005X· OSTI ID:21080644

Semenov, I B ^[1]; Mitrishkin, Yu V ^[2]; Subbotin, A A ^[1]; Vertinskii, A G ^[3]; Marusov, N L ^[1]; Sushin, I S ^[3]

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1. Russian Research Centre Kurchatov Institute, Nuclear Fusion Institute (Russian Federation)
2. Russian Academy of Sciences, Institute of Control Sciences (Russian Federation)
3. Moscow Institute of Physics and Technology (Russian Federation)

The main parameters of tokamak discharges are known to be limited by large-scale MHD instabilities. Sometimes, the instabilities lead to a rapid (on time scales of tens of microseconds) disruption of the discharge current and to the release of all the energy stored in the plasma column at the discharge chamber wall. This process, which is called the disruptive instability, may have irreversible catastrophic consequences for the operation of a fusion reactor. In the present paper, a study is made of the dynamics of self-oscillations in systems of two and six van der Pol coupled oscillators. A van der Pol coupled-oscillator model is used to develop a multivariable feedback controller based on the combined principle of compensating for internal cross feedbacks within the object and introducing damping feedbacks in each control channel. By using mathematical simulation methods, it is shown that the controller designed guarantees the suppression of self-oscillations in a system of van der Pol oscillators over a fairly broad range of parameters of the object under control (and thereby provides the structural stability of the object). The nonlinear control system model makes it possible to suppress coupled MHD perturbations developing in a tokamak plasma.

• OSTI ID: 21080644
• Journal Information: Plasma Physics Reports, Journal Name: Plasma Physics Reports Journal Issue: 2 Vol. 32; ISSN PPHREM; ISSN 1063-780X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPUTERIZED SIMULATION
CONTROL
CONTROL SYSTEMS
INSTABILITY
MAGNETOHYDRODYNAMICS
NONLINEAR PROBLEMS
OSCILLATIONS
OSCILLATORS
PERTURBATION THEORY
PLASMA
THERMONUCLEAR REACTORS
TOKAMAK DEVICES