scholarly journals Real-Time Control for the EHU Stellarator

Symmetry ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Izaskun Garrido ◽  
Javier Maseda ◽  
Itziar Martija ◽  
Aitor J. Garrido
Keyword(s):  
Real Time ◽  
Predictive Control ◽  
Magnetic Confinement ◽  
Good Alternative ◽  
Control Group ◽  
Fusion Reactors ◽  
Real Time Control ◽  
Time Control ◽  
Confinement Fusion ◽  
Physical Principles

At present, two main magnetic confinement fusion devices exist: tokamaks and stellarators. Moreover, stellarators have been demonstrated to be a good alternative to tokamaks, due to their ability to operate in continuous mode, which eventually translates into a higher commercial profitability. In stellarators, the magnetic confinement of the plasma is achieved exclusively by the coils, thus no electric current through the plasma is needed. In particular, this article presents the Columbia Non-Neutral Torus stellarator that is located in the Automatic Control Group of Euskal Herriko Unibertsitatea (EHU). This EHU stellarator maintains symmetry in its structure due to the topology of the mesh that is formed by its coils. A cornerstone of future fusion reactors is to obtain real-time control that enables a sustained reaction. In this article, a control-oriented model for the installed magnetic confinement coils is presented. The model is based on matrices that preserve symmetry, which is defined from physical principles and then validated by different sets of experimental data. Then, based on this model, a novel predictive control suited to this particular model with symmetric objective function is implemented in the numerical simulations, and its response is compared to that of traditional controllers. Finally, this control is implemented in a real plant and the satisfactory experiment results provide validation of both the numerical model and proposed controller.

Optimization of 3D controlled ELM-free state with recovered global confinement for KSTAR with n=1 resonant magnetic field perturbation

2021 ◽  
Author(s):  
SangKyeun Kim ◽  
Ricardo Shousha ◽  
Sang-Hee Hahn ◽  
Andrew Oakleigh Nelson ◽  
Josiah Wai ◽  
...  
Keyword(s):  
Real Time ◽  
Free State ◽  
Fusion Reactors ◽  
Ion Temperature ◽  
Real Time Control ◽  
Time Control ◽  
Transport Response ◽  
Magnetic Perturbations ◽  
Edge Localized Modes ◽  
Viable Approach

Abstract Mitigation of deleterious heat flux from edge-localized modes (ELMs) on fusion reactors is often attempted with 3D perturbations of the confining magnetic fields. However, the established technique of resonant magnetic perturbations (RMPs) also degrades plasma performance, complicating implementation on future fusion reactors. In this paper, we introduce an adaptive real-time control scheme on the KSTAR tokamak as a viable approach to achieve an ELM-free state and simultaneously recover high-confinement (βN~1.91, βp~1.53, and H98~0.9), demonstrating successful handling of a volatile complex system through adaptive measures. We show that, by exploiting a salient hysteresis process to adaptively minimize the RMP strength, stable ELM suppression can be achieved while actively encouraging confinement recovery. This is made possible by a self-organized transport response in the plasma edge which reinforces the confinement improvement through a widening of the ion temperature pedestal and promotes control stability, in contrast to the deteriorating effect on performance observed in standard RMP experiments. These results establish the real-time approach as an up-and-coming solution towards an optimized ELM-free state, which is an important step for the operation of ITER and reactor-grade tokamak plasmas.

Exact and Linearized Neural Predictive Control: A Turbocharged SI Engine Example

2007 ◽  
Vol 129 (4) ◽  
pp. 527-533 ◽  
Author(s):  
G. Colin ◽  
Y. Chamaillard ◽  
G. Bloch ◽  
A. Charlet
Keyword(s):  
Real Time ◽  
Linear Systems ◽  
Predictive Control ◽  
Control Method ◽  
Simulation Models ◽  
Real Time Control ◽  
Time Control ◽  
Non Linear ◽  
Non Linear Systems ◽  
Neural Predictive Control

This paper describes a real-time control method for non-linear systems based on model predictive control. The model used for the prediction is a neural network because of its ability to represent non-linear systems, its ability to be differentiated, and its simplicity of use. The feasibility and the performance of the method, based on on-line linearization, are demonstrated on a turbocharged spark-ignited engine application, where the simulation models used are very accurate and complex. The results, first in simulation and then on a test bench, show the implementation of the proposed control scheme in real time.

scholarly journals Optimization of 3D controlled ELM-free state with recovered global confinement for tokamak fusion plasmas

2021 ◽  
Author(s):  
SangKyeun Kim ◽  
Ricardo Shousha ◽  
SangHee Hahn ◽  
Andrew Nelson ◽  
Josiah Wai ◽  
...  
Keyword(s):  
Real Time ◽  
Free State ◽  
Fusion Reactors ◽  
Fusion Plasmas ◽  
Real Time Control ◽  
The Real ◽  
Time Control ◽  
Control Scheme ◽  
Edge Localized Modes ◽  
Viable Approach

Abstract Mitigation of deleterious heat flux from edge-localized modes (ELMs) on fusion reactors is often attempted with 3D perturbations of the confining magnetic fields. However, the established technique of resonant magnetic perturbations (RMPs) also degrades plasma performance, complicating implementation on future fusion reactors. In this paper, we introduce an adaptive real-time control scheme as a viable approach to simultaneously achieve both ELM-free states and recovered high-confinement (βN~1.91$ and HN~0.9), demonstrating successful handling of a volatile complex system through adaptive measures. We show that, by exploiting a salient hysteresis process to adaptively minimize the RMP strength, stable ELM suppression can be achieved while actively encouraging confinement recovery. This is made possible by a self-organized transport response in the plasma edge which reinforces the confinement improvement through a widening of the ion pedestal and promotes control stability, in contrast to the deteriorating effect on performance observed in standard RMP experiments. These results establish the real-time approach as an up-and-coming solution towards an optimized ELM-free state, which is an important step for the operation of ITER and reactor-grade tokamak plasmas. Notably, the real-time adaptive control scheme introduced here provides a path towards economic fusion reactors by maximizing the fusion gain while minimizing damage to machine components.

Real-Time Control Algorithms for a Hybrid Electric Race Car Using a Two-Level Model Predictive Control Scheme

2017 ◽  
Vol 66 (12) ◽  
pp. 10911-10922 ◽  
Author(s):  
Mauro Salazar ◽  
Camillo Balerna ◽  
Philipp Elbert ◽  
Fernando P. Grando ◽  
Christopher H. Onder
Keyword(s):  
Model Predictive Control ◽  
Real Time ◽  
Predictive Control ◽  
Control Algorithms ◽  
Real Time Control ◽  
Race Car ◽  
Time Control ◽  
Control Scheme ◽  
Level Model ◽  
Two Level Model
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