Analysis and Improved Control Strategy for New Generation Poloidal Field Power Supply

To improve the performance and dynamic response ability of poloidal field power supply (PFPS), the three-phase PWM converter-cascaded H-bridge inverter structure is adopted in the new generation PFPS. However, the load power of PFPS changes violently since the load characteristic is superconducting large inductance, which has a serious impact on the stability of the three-phase PWM converter control system. In this article, an improved dual closed-loop control strategy based on linear active disturbance rejection control (ADRC) is proposed to suppress the influence of load power disturbance, which is combined with the load power feedforward method and adding a decoupling link. Compared with the traditional control strategy based on PI controller, the simulation results show that the proposed control strategy has strong robustness to the change of load power, reduces the bus voltage fluctuation on the dc side, and improves the anti-interference ability and dynamic performance of the system.