Active disturbance rejection resonant controller with virtual damper for sub-10 kW three-leg four-wire inverters

Maintaining a consistent and high-quality voltage output in power systems based on renewable energy is a major challenge due to inherent uncertainties, dynamic load conditions, and control limitations. This paper presents a linear active disturbance rejection resonance controller with virtual damper for a three-leg four-wire voltage source inverter, which integrates an extended state observer with a resonant controller and a virtual damping mechanism. The proposed approach aims to address phase delay of the output signal and mitigate oscillations issues, commonly found in traditional active disturbance rejection control systems. By incorporating virtual damping, the designed controller enhances system stability across various operating conditions, including no-load to full-load as well as balanced and unbalanced loading scenarios. The results, supported by both frequency- and time-domain analyses, demonstrate improved dynamic performance, reduced total harmonic distortion, and strong resilience to parameter variations. The designed controller satisfies the grid code requirement of maintaining total harmonic distortion below 5% and preserves overall system stability even with up to 20% parameter uncertainties. The results indicate that the proposed controller provides a practical and effective solution for enhancing voltage regulation in distributed renewable energy applications. • Limited dynamic performance and phase delay issues in conventional inverter controllers. • Introducing an enhanced ADRRC–VD to improve voltage response and transient performance. • Employing a virtual damper to ensure stable operation under varying load conditions. • Achieving high power quality and low harmonic distortion in 3L4W inverter applications.