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This paper proposes an individual-phase control strategy for a four-leg three-phase inverter applied to distributed generation systems. In three-phase systems, voltages and currents can be decomposed into zero, positive, and negative-sequence components through coordinate transformation. However, conventional three-leg inverters cannot regulate the neutral-point voltage independently, making zero-sequence control infeasible and resulting in poor performance under single-phase or unbalanced load conditions. The four-leg inverter enables individual-phase control that significantly reduces total harmonic distortion in output voltages and currents, while maintaining stable voltage at the point of common coupling under severely unbalanced conditions. Coordinate transformation using all-pass filters can introduce delayed harmonic components into the virtual beta axis, resulting in unwanted harmonics in the synchronous d–q reference frame. To address this, the proposed method applies reactive power control using a phase-specific volt–ampere reactive strategy to enhance voltage stability. Additionally, a harmonic-compensated individual-phase control method is introduced to suppress distortion under nonlinear and unbalanced loads, incorporating band-pass filters and resonant controllers for each phase. The proposed control strategy is validated through simulation and experimental results, demonstrating improved voltage quality and system stability across various unbalanced scenarios.