A Comparative Analysis of Voltage Control Methods for Single-Phase Grid-Forming Inverters

This work compares three types of control-loop implementation for single-phase grid-forming inverters. The first two follow a single-loop approach using proportional resonant (PR) controllers in the Natural Reference Frame and proportional integral controllers in the synchronous reference (SRF-PI). The third control loop is also based on an SRF-PI controller. However, it has two loops, where the innermost one is related to the current that passes through the filter capacitor, and the outermost one is related to the inverter voltage. The article employs a simulation methodology to analyze the dynamic behavior of the control loops. In the established environments, it was shown that systems in SRF present a better transient response to step changes in the reference value. Furthermore, all three systems achieve zero error at steady state conditions.