A Reactive Power Circular-Chain Control Strategy for Single-Phase Parallel Inverters

In parallel inverter systems, traditional droop control often results in low power-sharing accuracy and significant circulating currents due to mismatched inverter output impedance. To improve power-sharing accuracy and minimize circulating currents, this paper proposes a control strategy for parallel inverters based on reactive power circular-chain adaptive virtual impedance. This strategy combines droop control with Circular Chain Control (3C) to create a circular-chain structure from the reactive power output of each parallel module. By constructing an adaptive virtual impedance that adjusts in real time according to reactive power requirements, this approach compensates for output impedance mismatches, achieving precise reactive power sharing. The effectiveness and feasibility of the proposed control strategy are validated through MATLAB simulations.