Analysis and Design of Voltage-controller Based on Single-state Feedback Active Damping for Grid-forming Converters

This paper investigates the analysis and design of digital single-loop voltage-controller for grid-forming voltage source converters with LC-filters. Inspired by structure diagram passive damping method, virtual resistance concept based on only capacitor feedback is used to realize active without need any current sensor, reducing thus system costs. It revealed from controller closed-loop that insertion an integrator in series a proportional resonant can significantly improve stability margin dynamic performance system, then be determined merely zero steady-state tracking error, which facilitates parameter tuning. A systematic root contours discrete z-domain proposed optimize parameters controller. The largest distance between poles unit circle achieved, indicates fastest under desired margins. Meanwhile, simple differentiator constructed backward-Euler plus lead-compensator replace noise-sensitive derivative term. In order evaluate control approach performance, tested laboratory setup different load conditions. obtained results verify effectiveness method validate analysis.