IEEE TRANSACTIONS ON POWER ELECTRONICS

Abstract—System efficiency and cost effectiveness are of critical importance for photovoltaic (PV) systems. This paper addresses the two issues by developing a novel three-port DC-DC converter for stand-alone PV systems, based on an improved Flyback-Forward topology. It provides a compact single-unit solution with a combined feature of optimized maximum power point tracking (MPPT), high step-up ratio, galvanic isolation and multiple operating modes for domestic and aerospace applications. A theoretical analysis is conducted to analyze the operating modes followed by simulation and experimental work. The paper is focused on a comprehensive modulation strategy utilizing both PWM and phase-shifted control that satisfies the requirement of PV power systems to achieve MPPT and output voltage regulation. A 250 W converter was designed and prototyped to provide experimental verification in term of system integration and high conversion efficiency.

[1]  Yi Zhao,et al.  High-Step-Up and High-Efficiency Fuel-Cell Power-Generation System With Active-Clamp Flyback–Forward Converter , 2012, IEEE Transactions on Industrial Electronics.

[2]  Weidong Xiao,et al.  Regulation of Photovoltaic Voltage , 2007, IEEE Transactions on Industrial Electronics.

[3]  Zhan Wang,et al.  Asymmetrical Duty Cycle Control and Decoupled Power Flow Design of a Three-port Bidirectional DC-DC Converter for Fuel Cell Vehicle Application , 2012, IEEE Transactions on Power Electronics.

[4]  Xinbo Ruan,et al.  Synthesis of Multiple-Input DC/DC Converters , 2010, IEEE Transactions on Power Electronics.

[5]  Onur Elma,et al.  A comparative sizing analysis of a renewable energy supplied stand-alone house considering both demand side and source side dynamics , 2012 .

[6]  Jian Cao,et al.  A Multiple-Input DC–DC Converter Topology , 2009, IEEE Transactions on Power Electronics.

[7]  Xunwei Yu,et al.  A new nonisolated three-port DC-DC converter with high step-up/down ratio , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[8]  P. Neudeck,et al.  Design and technology of compact high-power converters , 2000, Collection of Technical Papers. 35th Intersociety Energy Conversion Engineering Conference and Exhibit (IECEC) (Cat. No.00CH37022).

[9]  I. Batarseh,et al.  Modeling and Control of Three-Port DC/DC Converter Interface for Satellite Applications , 2010, IEEE Transactions on Power Electronics.

[10]  M. Sabahi,et al.  Modeling and Control of a New Three-Input DC–DC Boost Converter for Hybrid PV/FC/Battery Power System , 2012, IEEE Transactions on Power Electronics.

[11]  Runruo Chen,et al.  Full-Bridge Three-Port Converters With Wide Input Voltage Range for Renewable Power Systems , 2012, IEEE Transactions on Power Electronics.

[12]  A Elmitwally,et al.  Flexible Operation Strategy for an Isolated PV-Diesel Microgrid Without Energy Storage , 2011, IEEE Transactions on Energy Conversion.

[13]  M.G. Simoes,et al.  Three-Port Bidirectional Converter for Hybrid Fuel Cell Systems , 2007, IEEE Transactions on Power Electronics.

[14]  J.L. Duarte,et al.  Three-Port Triple-Half-Bridge Bidirectional Converter With Zero-Voltage Switching , 2008, IEEE Transactions on Power Electronics.

[15]  Hong-Seok Song,et al.  Idling Port Isolation Control of Three-Port Bidirectional Converter for EVs , 2012, IEEE Transactions on Power Electronics.

[16]  N. Mohan,et al.  Three-Port Series-Resonant DC–DC Converter to Interface Renewable Energy Sources With Bidirectional Load and Energy Storage Ports , 2009, IEEE Transactions on Power Electronics.

[17]  Zhe Zhang,et al.  Four Quadrants Integrated Transformers for Dual-Input Isolated DC–DC Converters , 2012, IEEE Transactions on Power Electronics.

[18]  J.L. Duarte,et al.  Transformer-Coupled Multiport ZVS Bidirectional DC–DC Converter With Wide Input Range , 2008, IEEE Transactions on Power Electronics.

[19]  Jaw-Kuen Shiau,et al.  Design of a Solar Power Management System for an Experimental UAV , 2009, IEEE Transactions on Aerospace and Electronic Systems.

[20]  Yi Zhao,et al.  PWM Plus Phase Angle Shift (PPAS) Control Scheme for Combined Multiport DC/DC Converters , 2012, IEEE Transactions on Power Electronics.

[21]  Vinod Khadkikar,et al.  Overview of maximum power point tracking technologies for photovoltaic power systems , 2011, IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society.

[22]  Runruo Chen,et al.  A Family of Three-Port Half-Bridge Converters for a Stand-Alone Renewable Power System , 2011, IEEE Transactions on Power Electronics.

[23]  J.W. Kolar,et al.  An Isolated Three-Port Bidirectional DC-DC Converter With Decoupled Power Flow Management , 2008, IEEE Transactions on Power Electronics.

[24]  T. Ise,et al.  Multilevel PWM inverters suitable for the use of stand-alone photovoltaic power systems , 2005, IEEE Transactions on Energy Conversion.

[25]  P. Thounthong.  Model Based-Energy Control of a Solar Power Plant With a Supercapacitor for Grid-Independent Applications , 2011, IEEE Transactions on Energy Conversion.

[26]  Xinbo Ruan,et al.  Isolated Single Primary Winding Multiple-Input Converters , 2011, IEEE Transactions on Power Electronics.

[27]  Javier Calvente,et al.  Bidirectional High-Efficiency Nonisolated Step-Up Battery Regulator , 2011, IEEE Transactions on Aerospace and Electronic Systems.

[28]  Jorge L. Duarte,et al.  Family of multiport bidirectional DC¿DC converters , 2006 .

[29]  Issa Batarseh,et al.  An Integrated Four-Port DC/DC Converter for Renewable Energy Applications , 2010, IEEE Transactions on Power Electronics.

[30]  Yung-Ruei Chang,et al.  High Step-Up Bidirectional Isolated Converter With Two Input Power Sources , 2009, IEEE Transactions on Industrial Electronics.

[31]  Bangyin Liu,et al.  Power flow control and optimization of a three-port converter for photovoltaic-storage hybrid system , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[32]  Prabodh Bajpai,et al.  Hybrid renewable energy systems for power generation in stand-alone applications: A review , 2012 .