Parallel-Connected Legs in a Grid-Tied Inverter System for Distributed Generation

Authors

  • G.J. Capellá Author
  • J. Pou Author
  • J. Zaragoza Author
  • S. Ceballos Author
  • I. Gabiola Author
  • E. Robles Author

DOI:

https://doi.org/10.24084/repqj09.630

Abstract

Grid-connected  high-power  inverters  are  often  used in distributed generation and power quality systems. Those inverters  have  to  handle  high  currents  in  order  to  achieve  high  power  values  without  resorting  to  higher  voltages.  Connecting  inverter  legs  in  parallel  is  a  proper  way  to  achieve  such  high  currents.   Such   parallel   connection   is   made   by   means   of   inductors  and  achieving  balanced  currents  among  the  legs  becomes  a  critical  issue.  Circulating  currents  may  produce  additional  losses  and  stress  to  the  converter’s  power  devices.  Therefore,   they   should   be   controlled   and   minimized.   An   efficient  technique  to  achieve  such  balance  is  presented  in  this  paper.  The  proposed  strategy  has  been  developed  on  a  grid-connected  three-phase  system.    Each  phase  of  the  inverter  is  made   up   of   three   legs   in   parallel.   Besides,   the   control   implemented  in  this  work  allows  full  regulation  of  the  power  factor.   This   way,   any   desired   power   factor   value   can   be   achieved   in   order   to   meet   grid-connection   requirements.   Simulation and experimental results are shown in this paper. 

Author Biographies

  • G.J. Capellá

    Department of Electronical Engineering

    Technical University of Catalonia.

    Campus of Terrassa, 08222 Terrassa (Spain)

    Phone:+0034 937398306, e-mail: capella@eel.upc.edu

  • J. Pou

    Department of Electronical Engineering

    Technical University of Catalonia.

    Campus of Terrassa, 08222 Terrassa (Spain)

    Phone:+0034 937398306, e-mail: pou@eel.upc.edu

  • J. Zaragoza

    Department of Electronical Engineering

    Technical University of Catalonia.

    Campus of Terrassa, 08222 Terrassa (Spain)

    Phone:+0034 937398306, e-mail: zaragoza@eel.upc.edu

  • S. Ceballos

    Tecnalia Technology Corporation, Energy Unit

    Zamudio, 48170 Zamudio-Bizkaia (Spain)

    Phone:+0034 944041444, e-mail: salvador.ceballos@tecnalia.com

  • I. Gabiola

    Tecnalia Technology Corporation, Energy Unit

    Zamudio, 48170 Zamudio-Bizkaia (Spain)

    Phone:+0034 944041444, e-mail: igor.gabiola@tecnalia.com

  • E. Robles

    Tecnalia Technology Corporation, Energy Unit

    Zamudio, 48170 Zamudio-Bizkaia (Spain)

    Phone:+0034 944041444, e-mail: eider.robles@tecnalia.com

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Published

2024-01-17

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Articles