Plasma current, position and shape feedback control on EAST

In this paper, a linear model for plasma current, position and shape control based on the plasma rigid motion assumption is presented and implemented in an EAST tokamak simulator. The simulator models the plasma, poloidal field (PF) coils, and power supplies, and is used to verify the control algorithm and optimize control parameters and PF coil current trajectories. Plasma position and shape control has been achieved during the last several EAST operation campaigns due to successful decoupling of plasma current, plasma position and shape. The control logic used and experimental results are described in detail. Diverted plasma shapes, including double null, upper and lower single null, and with elongation up to 2.0, triangularity in the range 0.4–0.6 and X point control accuracy of 1 cm, were successfully controlled. Smooth shape transition in the current ramp-up ensures that volt–seconds are saved and that plasma disruptions are avoided. Such control capability provides the basis for future high performance plasma operation.

[1]  J. A. Leuer,et al.  EAST plasma control system , 2008 .

[2]  D. A. Humphreys,et al.  Multivariable shape control development on the DIII-D tokamak , 1997, 17th IEEE/NPSS Symposium Fusion Engineering (Cat. No.97CH36131).

[3]  D. A. Humphreys,et al.  Control of plasma poloidal shape and position in the DIII-D tokamak , 1997, Proceedings of the 36th IEEE Conference on Decision and Control.

[4]  J. A. Leuer,et al.  Initial implementation of a multivariable plasma shape and position controller on the DIII-D tokamak , 2000, Proceedings of the 2000. IEEE International Conference on Control Applications. Conference Proceedings (Cat. No.00CH37162).

[5]  J. A. Leuer,et al.  Worldwide collaborative efforts in plasma control software development , 2008 .

[6]  B. P. Duval,et al.  The integration of the new advanced digital plasma control system in TCV , 2008 .

[7]  D. A. Humphreys,et al.  Next-generation plasma control in the DIII-D tokamak , 2003 .

[8]  J. A. Leuer,et al.  Implementation of model-based multivariable control on DIII–D , 2001 .

[9]  J. B. Lister,et al.  Plasma equilibrium response modelling and validation on JT-60U , 2002 .

[10]  Lei Liu,et al.  New achievements in the EAST plasma control system , 2010 .

[11]  R. H. Bulmer,et al.  Sustained Spheromak Physics Experiment (SSPX): design and physics results , 2012 .

[12]  J. A. Leuer,et al.  Development of ITER-relevant plasma control solutions at DIII-D , 2007 .

[13]  M. Ariola,et al.  Plasma shape control for the JET tokamak: an optimal output regulation approach , 2005, IEEE Control Systems.

[14]  L. L. Lao,et al.  Real time equilibrium reconstruction for tokamak discharge control , 1998 .

[15]  F. Sartori,et al.  The Joint European Torus , 2006, IEEE Control Systems.

[16]  L. Lao,et al.  Reconstruction of current profile parameters and plasma shapes in tokamaks , 1985 .

[17]  D. A. Humphreys,et al.  DIII-D INTEGRATED PLASMA CONTROL SOLUTIONS FOR ITER AND NEXT- GENERATION TOKAMAKS , 2008 .

[18]  J. Lister,et al.  Measurement of the open loop plasma equilibrium response in TCV , 1999 .

[19]  Xiao Bingjia,et al.  Implementation of Gas Control Algorithm in EASTPCS , 2009 .