Event-Triggered Multi-Mode Adaptive LADRC-MPC for Auxiliary Power Supplies in VSC-HVDC Converter Stations

Auxiliary power supplies in voltage source converter-based high-voltage direct current (VSC-HVDC) converter stations are exposed to severe bus voltage sags, abrupt load changes, and wide-range operating conditions that seriously challenge conventional control strategies. This paper proposes an event-triggered multi-mode adaptive control architecture which combines linear active disturbance rejection control (LADRC) with model predictive control (MPC) in a hierarchical manner. The novelty of this work lies in embedding mode-adaptive prediction and disturbance feedforward into an event-triggered LADRC-MPC cascade, a combination that has not been reported for high-frequency auxiliary power converters in HVDC stations. The scheme features an adaptive event-triggering mechanism that cuts the MPC computational burden by over 80% in steady-state, a multi-mode LADRC outer loop handling continuous/discontinuous conduction mode (CCM/DCM) transitions smoothly, and a disturbance-feedforward MPC inner loop embedding the estimated disturbance into the cost function for proactive disturbance rejection. In addition, the input voltage is reconstructed from the inductor voltage balance using linear extended state observer (LESO) estimates, eliminating the dedicated input-voltage sensor. Simulations on a 50 kHz Boost converter show that the proposed method confines the voltage fluctuation during CCM-to-DCM transitions from ±28 V to within ±2.5 V; shortens the recovery time under input-voltage steps from 15 ms to 4.5 ms; and keeps the steady-state error within ±0.05% of the 600 V output, well inside the ±0.5% specification over the full load range. The event-triggered mechanism lowers the average CPU occupancy from 58% under periodic execution to below 15%, enabling high-frequency auxiliary power applications in HVDC systems.