Analysis of modular DCM Flyback converters in input parallel connections with parametric mismatches

This paper analyzes the effects of parameter mismatches in the balance mechanism of modular DC-DC Flyback converters operating in discontinuous conduction mode. The natural current and voltage distributions among modules are evaluated when mismatches on duty cycles, transformer magnetizing inductances and transform turns ratios are present. From these results, the critical values of inductances and duty cycles that assure the discontinuous operation are equated. The smallsignal equivalent circuit for Input-Parallel-Output-Series and Input-Parallel-Output-Parallel connections are found, followed by a simple control strategy. The theoretical analysis is verified by experimental results obtained with a prototype composed of three 200 W Flyback modules, with a rated power of 600 W and maximum efficiency of 95.5%. Results corroborate the proposed equations for the steady state balance and dynamic behavior of both connections, highlighting the modular characteristic of the converter.

[1]  Leila Parsa,et al.  Series-Input Parallel-Output Modular-Phase DC–DC Converter With Soft-Switching and High-Frequency Isolation , 2016, IEEE Transactions on Power Electronics.

[2]  Zhijie Zhang,et al.  A modular auxiliary power supply system and its input voltage sharing control strategy , 2017, 2017 IEEE Transportation Electrification Conference and Expo, Asia-Pacific (ITEC Asia-Pacific).

[3]  R. Ayyanar,et al.  Common duty ratio control of input series connected modular DC-DC converters with active input voltage and load current sharing , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[4]  Xiangning He,et al.  Common-Duty-Ratio Control of Input-Parallel Output-Parallel (IPOP) Connected DC–DC Converter Modules With Automatic Sharing of Currents , 2012, IEEE Transactions on Power Electronics.

[5]  Ivo Barbi,et al.  Modular Two-Switch Flyback Converter and Analysis of Voltage-Balancing Mechanism for Input-Series and Output-Series Connection , 2019, IEEE Transactions on Power Electronics.

[6]  Ivo Barbi,et al.  Input-series and output-series connected modular full-bridge PWM DC-DC converter with capacitive output filter and common duty cycle , 2014, 2014 11th IEEE/IAS International Conference on Industry Applications.

[7]  Mukti Barai,et al.  Design and implementation of voltage mode digital controller for flyback converter operating in discontinuous conduction mode (DCM) , 2016, 2016 7th India International Conference on Power Electronics (IICPE).

[8]  C. Bunlaksananusorn,et al.  Performance comparison of continuous conduction mode (CCM) and discontinuous conduction mode (DCM) flyback converters , 2003, The Fifth International Conference on Power Electronics and Drive Systems, 2003. PEDS 2003..

[9]  Lu Qu,et al.  Input Voltage Sharing Control Scheme for Input Series and Output Parallel Connected DC–DC Converters Based on Peak Current Control , 2019, IEEE Transactions on Industrial Electronics.

[10]  Ivo Barbi,et al.  Input-series and output-series connected modular single-switch flyback converter operating in the discontinuous conduction mode , 2016 .

[12]  Youguang Guo,et al.  Modular Medium-Voltage Grid-Connected Converter With Improved Switching Techniques for Solar Photovoltaic Systems , 2017, IEEE Transactions on Industrial Electronics.

[13]  Mehran Sabahi,et al.  Parallel input series output DC/DC converter for fuel cell applications , 2014, The 5th Annual International Power Electronics, Drive Systems and Technologies Conference (PEDSTC 2014).

[14]  M Bragard,et al.  The Balance of Renewable Sources and User Demands in Grids: Power Electronics for Modular Battery Energy Storage Systems , 2010, IEEE Transactions on Power Electronics.

[15]  A. Piazzesi,et al.  Series connection of 3.3 kV IGBTs with active voltage balancing , 2004, 2004 IEEE 35th Annual Power Electronics Specialists Conference (IEEE Cat. No.04CH37551).

[16]  Marcin Parchomiuk,et al.  Modular power converter topologies for energy storage and electric power distribution systems , 2017, 2017 Progress in Applied Electrical Engineering (PAEE).

[17]  Hui Li,et al.  High-Frequency Transformer Isolated Bidirectional DC–DC Converter Modules With High Efficiency Over Wide Load Range for 20 kVA Solid-State Transformer , 2011, IEEE Transactions on Power Electronics.

[18]  Linbing Wang,et al.  System performance analysis of the input-parallel and output-series full-bridge converters considering parameter difference , 2011, 2011 3rd International Conference on Electronics Computer Technology.

[19]  Rik W. De Doncker,et al.  Development and demonstration of a medium-voltage high-power DC-DC converter for DC distribution systems , 2014, 2014 IEEE 5th International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[20]  Cong Wang,et al.  Research on voltage sharing for input-series-output-series phase-shift full-bridge converters with common-duty-ratio , 2011, IECON 2011 - 37th Annual Conference of the IEEE Industrial Electronics Society.

[21]  Telles Brunelli Lazzarin,et al.  Modular ISOP Flyback converter: Analysis of auto-balancing mechanism in steady state , 2017, 2017 IEEE 8th International Symposium on Power Electronics for Distributed Generation Systems (PEDG).

[22]  Yiqing Lian,et al.  Modular input-parallel output-series DC/DC converter control with fault detection and redundancy , 2015 .

[23]  George L. Kusic,et al.  A case for medium voltage DC for distribution circuit applications , 2011, 2011 IEEE/PES Power Systems Conference and Exposition.

[24]  Ivo Barbi,et al.  Design of a 660 V / 15 kVA single-phase UPS based on series connection of low-output-voltage modular UPS , 2012 .