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Title: Closed-loop simulation with Grad-Shafranov equilibrium evolution for plasma control system development

Journal Article · · Fusion Engineering and Design

Plasma control design increasingly depends on fast simulations able to connect to operational plasma control system (PCS) software for iterative development. GSevolve is a nonlinear free-boundary simulation that evolves the Grad-Shafranov equilibrium including current and pressure profiles, and can connect to all versions of the DIII-D PCS operational on devices around the world. Its ability to simulate the evolution of current continuously from open to closed field lines enables GSevolve to simulate full-discharge control from breakdown through plasma termination. GSevolve is compliant with the Plasma Control System Simulation Platform (PCSSP), a Matlab/Simulink®-based environment that serves as the primary framework for development of the ITER Plasma Control System (PCS). The code employs a novel response function-updating scheme to achieve fast simulations. The plasma evolves linearly until a significant shape change triggers a nonlinear update of the response while enforcing a prescribed accuracy. Old responses are recalled if the plasma changes back to an old shape. The equilibrium is a function of a state vector containing axisymmetric conductor currents and parameters related to parallel and perpendicular currents, which evolves according to an efficient state space circuit formulation. Control design and validation results are presented for simulations of DIII-D and EAST, connected to their corresponding versions of the DIII-D PCS.

Research Organization:
General Atomics, San Diego, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE
Grant/Contract Number:
FC02-04ER54698; SC0010685
OSTI ID:
1609207
Alternate ID(s):
OSTI ID: 1562548
Journal Information:
Fusion Engineering and Design, Vol. 146, Issue B; ISSN 0920-3796
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

References (5)

Real-time physics-model-based simulation of the current density profile in tokamak plasmas journal August 2011
A simulation environment for ITER PCS development journal May 2014
EAST plasma control system journal April 2008
Development of ITER-relevant plasma control solutions at DIII-D journal July 2007
Experimental vertical stability studies for ITER performance and design guidance journal September 2009

Figures / Tables (4)