Large-signal stability analysis and enhancement strategy of ITER power supply system

• Proposed a large-signal model of the ITER power supply system for stability analysis. • Identified the stable operating region of the load and revealed key factors affecting stability through large-signal analysis. • Proposed a virtual capacitor control strategy to enhance the large-signal stability of the system. The large power disturbances of ITER pulsed loads pose significant challenges to the stable operation of its power supply system. However, existing studies of ITER power supply system focus on small-signal stability, while its large-signal stability analysis remains lacking. In this paper, a large-signal model of the power supply system, including phase-controlled AC/DC circuits and reactive power compensation, is developed for the first time using an equivalent circuit and model simplification approach. Based on the established model, a large-signal stability criterion is derived to reveal the impact of load power and system configuration on system stability. Furthermore, a virtual capacitor control strategy is proposed to enhance the large-signal stability of the system. The effectiveness of the proposed method is verified through MATLAB/Simulink and experiments. This study provides a modeling and analysis framework for large-signal stability of the ITER power supply system under pulsed disturbances.