Multi-stage Model Predictive Control Algorithm with Eddy Current Compensation for FTPMF

Many vacuum electronic devices require a power supply to drive magnets to generate a flat top pulsed magnetic field in their cavities. However, there is a thick copper plating layer in cavities, resulting in serious eddy current hysteresis. In this paper, a control algorithm based on variable-step model predictive control is proposed for the eddy current compensation of high-power gyrotron terahertz wave sources. Compared to traditional flat top pulse current sources, the proposed algorithm generates a controlled current overshoot in the magnet, increasing the magnetic field stabilization speed by approximately 50%. The control algorithm has multiple operating states, and can achieve computational load balancing by adjusting the sampling time and prediction step length under different states, while generating a more stable flat top pulse current than traditional methods.