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This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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More from UWC 2020: Round 2
This year’s Utility Working Conference had a dynamic opening plenary and a packed roster of informative sessions. Following are recaps of some of the 2:00 p.m. (EDT) sessions that took place.
Don't miss Newswire's coverage of the opening plenary and the sessions at 12:00 pm.
Eugenio Schuster, Miroslav Krstic, George Tynan
Fusion Science and Technology | Volume 43 | Number 1 | January 2003 | Pages 18-37
Technical Paper | dx.doi.org/10.13182/FST03-A246
Articles are hosted by Taylor and Francis Online.
Control of plasma density and temperature magnitudes, as well as their profiles, are among the most fundamental problems in fusion reactors. Existing efforts on model-based control use control techniques for linear models. In this work, a zero-dimensional nonlinear model involving approximate conservation equations for the energy and the densities of the species was used to synthesize a nonlinear feedback controller for stabilizing the burn condition of a fusion reactor. The subignition case, where the modulation of auxiliary power and fueling rate are considered as control forces, and the ignition case, where the controlled injection of impurities is considered as an additional actuator, are treated separately.The model addresses the issue of the lag due to the finite time for the fresh fuel to diffuse into the plasma center. In this way we make our control system independent of the fueling system and the reactor can be fed either by pellet injection or by puffing. This imposed lag is treated using nonlinear backstepping.The nonlinear controller proposed guarantees a much larger region of attraction than the previous linear controllers. In addition, it is capable of rejecting perturbations in initial conditions leading to both thermal excursion and quenching, and its effectiveness does not depend on whether the operating point is an ignition or a subignition point.The controller designed ensures setpoint regulation for the energy and plasma parameter with robustness against uncertainties in the confinement times for different species. Hence, the controller can increase or decrease , modify the power, the temperature or the density, and go from a subignition to an ignition point and vice versa.