Complex-variable sliding-mode control of non-ideal grid-tied self-synchronized inverter for DC-link capacitance reduction
This paper focuses on complex-variable sliding-mode control (CV-SMC) of grid-following inverters that interface renewable energy sources (RESs) with non-ideal grids subject to imbalances, harmonic distortion, frequency variations and voltage drops. The following three control objectives are set: (1)...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/75212 |
| Acceso en línea: | http://hdl.handle.net/10810/75212 |
| Access Level: | acceso abierto |
| Palabra clave: | grid following inverter grid voltage observer complex-variable sliding-mode control (CV-SMC) DC-link capacitance reduction non-ideal grid renewable energy source |
| Sumario: | This paper focuses on complex-variable sliding-mode control (CV-SMC) of grid-following inverters that interface renewable energy sources (RESs) with non-ideal grids subject to imbalances, harmonic distortion, frequency variations and voltage drops. The following three control objectives are set: (1) Substantial DC-link capacitance reduction via high-dynamic-performance control of the DC-link voltage, (2) phase-locked loop (PLL)-less and grid voltage sensorless control, and (3) injected grid current free from imbalances and harmonic distortion. Objectives 1 and 3 are tackled by proposing a CV-SMC scheme based on a non-conventional, energy-based, nonlinear switching function, combined with a method for computing the instantaneous reference values it contains. Such switching function leads to command the DC-link voltage together with the grid current by means of a single high-dynamic-performance control-loop. As for objective 2, a nonlinear observer estimating both the grid voltage and its frequency is proposed to replace the typical ‘‘grid voltage sensors + PLL’’ solution, thus enabling the inverter to self-synchronize with non ideal grids by measuring only the grid current. The design, tuning, stability analysis and implementation of both the CV-SMC algorithm and the observer are addressed. Simulation and experimental results confirm the proposal’s ability to meet the three control objectives in presence of grid disturbances. |
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