Nowadays, stand‐alone dispersed generation -DG- supplied from renewable energies is rapidly growing. In such a condition, four‐leg inverter can be considered as a successful option to supply unbalanced loads, especially in transformerless systems. In this paper, four‐leg inverter is modeled considering the fourth line inductor. The neutral -fourth- line inductor causes a high coupling through control variables in the natural reference frame. To avoid several transformations among reference frames, a new digital controller based on deadbeat -DB- theory is proposed in the natural reference frame to regulate the load voltages under coupled model. The proposed method offers simplicity, ease of digital implementation, and a fast dynamic response. Furthermore, a delay compensation procedure is also proposed to make the overall performance of the proposed DB controller better. Experimental tests based on a 3kW prototype are implemented to support the analytical analysis. Different tests under various single/three‐phase, nonlinear/linear, and unbalanced/balanced load conditions were performed, which confirm the excellent performance of the proposed control system.

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