Precise Power Sharing Among Parallel Inverters in an AC Microgrid Using Decentralized Control Based on Modified <i>P‐f/Q‐V</i> and <i>P‐V/Q‐f</i> Droop Characteristics

ABSTRACT This paper introduces an innovative method for enhanced power distribution in an AC microgrid (MG), utilizing parallel inverters with a decentralized droop control strategy. The conventional droop ( P‐f/Q‐V ) control is implemented for inductive‐dominant lines and the reverse droop ( P‐V/Q‐f ) control for resistive‐dominant lines. However, since line impedance often includes both inductive and resistive components, a combined droop approach ( P‐f/Q‐V and P‐V/Q‐f ) is considered. Challenges like frequency and voltage deviations, improper power sharing, and instability at the point of common coupling arise from line impedance mismatches in systems with multiple distributed generators (DGs) operating in parallel. To address these, the paper proposes adding a virtual impedance loop to the existing control scheme. Two case studies are analyzed: The first examines the combined droop approach for two DGs, while the second evaluates the existing control scheme along with improved virtual impedance control for mismatched line impedance scenario. The MG model is validated using the OPAL‐RT OP 4510 digital simulator, with system modeling performed in the MATLAB/Simulink environment. The simulation results demonstrate improvements in stability of voltage, restoration of frequency, current, and power sharing accuracy for all case studies. A comparative analysis further highlights the percentage improvement in power sharing during transient conditions.