A novel hybrid Model Predictive Control (MPC) algorithm has been designed for simultaneous safety factor (q) profile and stored energy (w) control while incorporating the pulse-width-modulation constraints associated with the neutral beam injection (NBI) system. Regulation of the q-profile has been extensively shown to be a key factor for improved confinement as well as non-inductive sustainment of the plasma current. Simultaneous control of w is necessary to prevent the triggering of pressure-driven magnetohydrodynamic instabilities as the controller shapes the q profile. Conventional MPC schemes proposed for q-profile control have considered the NBI powers as continuous-time signals, ignoring the discrete-time nature of these actuators and leading in some cases to performance loss. The hybrid MPC scheme in this work has the capability of incorporating the discrete-time actuator dynamics as additional constraints. In nonlinear simulations, the proposed hybrid MPC scheme demonstrates improved q-profile+w control performance for NSTX-U operating scenarios.
この論文では、中性粒子ビーム注入(NBI)システムの制約を組み込んだ、安全係数(q)プロファイルと蓄積エネルギー(w)の同時制御のためのハイブリッド型モデル予測制御(MPC)アルゴリズムが提案されています。qプロファイルの制御は閉じ込め性能と非誘導電流維持に重要で、wの制御は圧力駆動型MHD不安定性の抑制に必要です。従来のMPCスキームではNBIアクチュエータの離散時間特性を無視していましたが、提案手法ではそれを制約条件に組み込むことで、より良いq+w制御性能が得られることが示されています。