Adaptive Virtual Capacitor Control Based on LADRC for Voltage Regulation in Industrial DC Microgrids

Abstract

To address the critical voltage stability of industrial DC microgrids serving sensitive loads, virtual capacitor control is a promising technique for inertia enhancement. However, conventional virtual capacitor control, with its fixed parameters and limited disturbance rejection capability, struggles to maintain qualified voltage quality, threatening the reliable operation of industrial equipment. This paper proposes a novel adaptive virtual capacitor control strategy based on linear active disturbance rejection control (LADRC). The key contribution is a novel control architecture where the virtual capacitor is not predetermined but is adaptively modulated by real-time disturbance estimated by LADRC. This unique feedback mechanism allows the system to proactively counteract both external load changes and internal parameter uncertainties, achieving superior voltage regulation. Furthermore, an integrated sliding time window filter ensures smooth control action by mitigating oscillations from voltage ripple. The proposed strategy's effectiveness in simultaneously enhancing voltage deviation suppression, ripple mitigation, and dynamic inertia support is validated through simulation and hardware-in the-loop (HIL) experiments.