Decoupled Per-Phase Control of a Four-Leg Grid-Feeding Inverter for Voltage Unbalance Mitigation in Low-Voltage Networks
The increasing integration of distributed energy resources and single-phase loads in low-voltage distribution networks introduces significant voltage unbalance, degrading power quality and compromising supply reliability. Existing four-leg inverter solutions typically rely on grid-forming operation...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:dnet:addi________::b5bdcaabb753b111094a6a2fb89c1145 |
| Acceso en línea: | http://hdl.handle.net/10810/79771 |
| Access Level: | acceso abierto |
| Palabra clave: | low-voltage voltage unbalance phase independent grid-feeding bidirectional power flow current control |
| Sumario: | The increasing integration of distributed energy resources and single-phase loads in low-voltage distribution networks introduces significant voltage unbalance, degrading power quality and compromising supply reliability. Existing four-leg inverter solutions typically rely on grid-forming operation or sequencecomponent decomposition, limiting their applicability in grid-connected scenarios with parallel utility supply. This paper proposes a decoupled per-phase current control strategy for a four-leg inverter operating exclusively in grid-feeding mode, which constitutes the main scientific contribution of this work. The method assigns an independent proportional-resonant controller to each phase, enabling per-phase active power regulation and bidirectional current flow without sequence-component transformation, ensuring stable parallel operation with the utility network. A DC bus provides the necessary voltage stiffness for current regulation. Experimental validation under diverse unbalanced operating conditions demonstrates a reduction of the voltage unbalance ratio to zero, with total harmonic distortion of injected currents remaining below 15% in all tested cases. These results confirm the suitability of the proposed framework for low-voltage networks with high penetration of distributed generation. |
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