An Adaptive Control Strategy for Long-Pulse Magnet System With Low-Ripple Flat-Top Magnetic Field

An optimal and adaptive control strategy for the flat-top long-pulse magnet system of single or dual coaxially nested coils is proposed and designed in this paper. By integrating a voltage feedback control loop and an adaptive feedforward compensation algorithm in the conventional current control configuration, the magnet system's dynamic field response could be further improved with little field overshoot and low-frequency oscillation. For the identification of the long-pulse magnets' dynamically varying resistance needed for the compensation loop in the proposed control strategy, a novel computation method employing the gradient descent technique is presented in details. Simulation results in generating high flat-top low ripple pulsed field are presented comprehensively to validate the good dynamic performance of the adopted new controller and the feasibility of the online computation model.