Control of a single-switch two-input buck converter for MPPT of two PV strings

In this paper, the Two-Input Buck (TIBuck) converter is proposed as the DC/DC stage for photovoltaic (PV) cascaded converters. This converter is attractive for this application because it is cost-effective and reliable and can achieve dual maximum power point tracking (MPPT) with only one power tran...

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Detalles Bibliográficos
Autores: Urtasun Erburu, Andoni, Dah-Chuan Lu, Dylan
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/31326
Acceso en línea:https://hdl.handle.net/2454/31326
Access Level:acceso abierto
Palabra clave:Dual MPPT
Photovoltaic power systems
Small-signal modeling
Two-input converters
Voltage control
Descripción
Sumario:In this paper, the Two-Input Buck (TIBuck) converter is proposed as the DC/DC stage for photovoltaic (PV) cascaded converters. This converter is attractive for this application because it is cost-effective and reliable and can achieve dual maximum power point tracking (MPPT) with only one power transistor. However, due to the simplified and integrated structure, the nonlinear characteristics of the converter and the two PV arrays complicate the control. By means of a small-signal modeling, the control theme of the two PV voltages is formulated and the effect of the nonlinearities is presented. It is shown that, while fast voltage dynamics are achieved for the first input, the second-input voltage response depends on the second-stage converter control. Simulation and experimental results are reported to validate the theoretical analysis, showing the dual MPPT capability.