Coordinated Control Strategy for Distributed Energy Storage MMC Drive System Based on ESO-MPC and Hierarchical Equalization

Abstract

High-power induction motor drives (e.g., mine hoists) based on DEMMC face severe energy imbalances and power surges under extreme dynamics. This paper proposes a hierarchical coordinated control strategy to address these challenges and ensure system stability under variable-speed, heavy-load conditions. An ESO-MPC framework is established for robust torque tracking and active disturbance rejection. A dual-layer State of Charge (SOC) balancing mechanism is developed, employing fuzzy-logic-based nonlinear gain for inter-arm regulation and a novel DO-CDPWM strategy for rapid intra-arm equalization. The approach is validated via MATLAB/Simulink. Simulation results demonstrate that the ESO-MPC has an ultra-fast current settling time of 2 ms (within a 2% error band) with negligible overshoot. The proposed balancing strategy suppresses intra-arm SOC deviation from 4% to 0.5% within 0.2s, while effectively eliminating second-order harmonic circulating currents. A coordinated control strategy integrating ESO-MPC and dual-layer SOC balancing is proposed for DE-MMC mine hoists. Simulations demonstrate a 1ms current response and rapid SOC equalization (4% to 0.5%) within 0.2s. This strategy decouples motor drive from energy management, ensuring stable operation under heavy-load conditions. The proposed strategy effectively decouples motor drive from energy management, offering superior dynamic performance and global energy equilibrium compared to traditional PIbased methods, making it highly suitable for high-power mining applications.