Model-based Linear Quadratic Integral Control Design for q-profile Shaping in EAST
Z. Wang, H. Wang, E. Schuster, Y. Huang, Z. Luo, Q. Yuan, B. Xiao, D. Humphreys
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Fort Lauderdale, FL, USA, October 21-25, 2019
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Abstract
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In order to achieve advanced modes of operation, characterized by
confinement improvement and possible steady-state operation, control
capabilities for shaping the spatial profile of the toroidal current
density, or equivalently the safety factor 𝑞 or the gradient of the
poloidal magnetic flux, are essential. A linear quadratic integral
(LQI) control-design approach has been followed in this work to further
develop such control capabilities in EAST. The controllers, which have
been designed based on a first-principles-driven control-oriented model
of the poloidal magnetic flux profile evolution, have the capability of
regulating several points of the q profile and its integral properties
such as the internal inductance 𝑙𝑖. Moreover, by controlling the plasma
current \textit{Ip} and the powers of both the low frequency (2.45 GHz)
and the high-frequency (4.60 GHz) lower hybrid wave sources, the
controllers can also regulate 𝛽𝑁. Nonlinear simulations show that the
controllers can effectively regulate a combination of 𝑞(0.1), 𝑞(0.5),
𝑞(0.9), 𝑙𝑖 and 𝛽𝑁. The proposed control laws have been implemented in
the recently developed Profile Control category in the EAST Plasma
Control System (PCS) with the ultimate goal of testing them experimentally.
