Input-series-output-parallel connected modular high frequency isolated AC–AC converters with positive compensation of inner-current loop

A control strategy for input-series-output-parallel (ISOP) connected modular high frequency isolated AC–AC converter is proposed in this study. The circulating currents among all the constituent modules are avoided by the proposed pulse width modulation sequence generation method. Based on the revealed relationship between input voltage sharing (IVS) and output current sharing (OCS), a stable control strategy is proposed by using an output voltage loop and positive inner-current compensation loops. The individual input voltage sharing loops are eliminated. With the proposed control strategy, OCS or IVS can be achieved well for ISOP modular AC–AC converters under both steady and dynamic state, even in the case when the parameters of individual modules are mismatched. Simulation and experimental results are presented to verify the effectiveness of the control strategy.

[1]  Xinbo Ruan,et al.  Input-Series and Output-Parallel Connected Inverter System for High Input Voltage Applications , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[2]  Pavel Drábek,et al.  New Configuration of Traction Converter With Medium-Frequency Transformer Using Matrix Converters , 2011, IEEE Transactions on Industrial Electronics.

[3]  Xiaozhong Liao,et al.  Decentralized Inverse-Droop Control for Input-Series–Output-Parallel DC–DC Converters , 2015, IEEE Transactions on Power Electronics.

[4]  Ka Wai Eric Cheng,et al.  New power sharing scheme with correlation control for input-parallel-output-series-based interleaved resonant inverters , 2014 .

[5]  Xiaozhong Liao,et al.  Control Strategy for Input-Series–Output-Parallel High-Frequency AC Link Inverters , 2012, IEEE Transactions on Industrial Electronics.

[6]  S. J. Finney,et al.  Series-Connected IGBTs Using Active Voltage Control Technique , 2013, IEEE Transactions on Power Electronics.

[7]  Ivo Barbi,et al.  Split-phase switched-capacitor ac–ac converter , 2015 .

[8]  Rainer Marquardt,et al.  A new AC/AC multilevel converter family , 2005, IEEE Transactions on Industrial Electronics.

[9]  R. Ayyanar,et al.  Active input-voltage and load-current sharing in input-series and output-parallel connected modular DC-DC converters using dynamic input-voltage reference scheme , 2004, IEEE Transactions on Power Electronics.

[10]  Kasemsan Siri,et al.  Uniform Voltage Distribution Control for Series Connected DC–DC Converters , 2007 .

[11]  Stephen J. Finney,et al.  Analysis of modular multilevel converter capacitor voltage balancing based on phase voltage redundant states , 2012 .

[12]  Xinbo Ruan,et al.  Control Strategy for Input-Series–Output-Parallel Converters , 2009, IEEE Transactions on Industrial Electronics.

[13]  Mohammad Tavakoli Bina,et al.  Classification of multilevel converters with a modular reduced structure: implementing a prominent 31-level 5 kVA class B converter , 2015 .

[14]  Xiaozhong Liao,et al.  Input-series and output-parallel connected single stage buck type modular AC–DC converters with high-frequency isolation , 2015 .

[15]  Shin-Ju Chen,et al.  Analysis and implementation of an interleaved series input parallel output active clamp forward converter , 2013 .

[16]  Rolando Burgos,et al.  Review of Solid-State Transformer Technologies and Their Application in Power Distribution Systems , 2013, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[17]  S. Munk‐Nielsen,et al.  Analysis and modelling of circulating current in two parallel-connected inverters , 2015 .

[18]  M. Lucanu,et al.  Single-phase direct AC–AC step-down converter , 2014 .

[19]  Daolian Chen.  Novel Current Mode AC/AC Converters with High Frequency AC Link , 2008, 2005 IEEE 36th Power Electronics Specialists Conference.

[20]  Seyed Hossein Hosseini,et al.  Zero-voltage switching bi-directional power electronic transformer , 2010 .

[21]  Deshang Sha,et al.  Cross-Feedback Output-Current-Sharing Control for Input-Series-Output-Parallel Modular DC–DC Converters , 2010, IEEE Transactions on Power Electronics.