Recovery of inter-row shading losses using differential power-processing submodule DC–DC converters

Abstract Large commercial photovoltaic (PV) systems can experience regular and predictable energy loss due to both inter-row shading and reduced diffuse irradiance in tightly spaced arrays. This paper investigates the advantages of replacing bypass diodes with submodule-integrated DC–DC converters (subMICs) to mitigate these losses. Yearly simulations of commercial-scale PV systems were conducted considering a range of row-to-row pitches. In the limit case of array spacing (unity ground coverage), subMICs can confer a 7% increase in annual energy output and peak energy density (kW h/m 2 ). Simulation results are based on efficiency assumptions experimentally confirmed by prototype submodule differential power-processing converters.

[1]  M van Schalkwijk,et al.  Dependence of diffuse light blocking on the ground cover ratio for stationary PV arrays , 1997 .

[2]  Dragan Maksimovic,et al.  Performance of Power-Limited Differential Power Processing Architectures in Mismatched PV Systems , 2015, IEEE Transactions on Power Electronics.

[3]  William A. Beckman,et al.  Improvement and validation of a model for photovoltaic array performance , 2006 .

[4]  Dirk C. Jordan,et al.  Technology and Climate Trends in PV Module Degradation: Preprint , 2012 .

[5]  Felipe A. Mejia,et al.  Soiling losses for solar photovoltaic systems in California , 2013 .

[6]  Beomseok Choi.  Differential Power Processing Submodule Integrated Converters for Photovoltaic Power Systems , 2015 .

[7]  Philip T. Krein,et al.  Impact of differential power processing on inter-row shading in solar arrays , 2015, 2015 IEEE 16th Workshop on Control and Modeling for Power Electronics (COMPEL).

[8]  J. Michalsky,et al.  Modeling daylight availability and irradiance components from direct and global irradiance , 1990 .

[9]  P. T. Krein,et al.  Differential Power Processing for Increased Energy Production and Reliability of Photovoltaic Systems , 2013, IEEE Transactions on Power Electronics.

[10]  R. W. Erickson,et al.  Characterization of Power Optimizer Potential to Increase Energy Capture in Photovoltaic Systems Operating Under Nonuniform Conditions , 2013, IEEE Transactions on Power Electronics.

[11]  Chris Deline,et al.  Evaluation of Maxim module-Integrated electronics at the DOE Regional Test Centers , 2014, 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC).

[12]  Dimitrios Passias,et al.  Shading effects in rows of solar cell panels , 1984 .

[13]  Chris Deline,et al.  Photovoltaic Shading Testbed for Module-Level Power Electronics: 2014 Update , 2014 .

[14]  Dragan Maksimovic,et al.  A branch and bound algorithm for high-granularity PV simulations with power limited SubMICs , 2013, 2013 IEEE 14th Workshop on Control and Modeling for Power Electronics (COMPEL).

[15]  Dragan Maksimovic,et al.  Control of Submodule Integrated Converters in the Isolated-Port Differential Power-Processing Photovoltaic Architecture , 2014, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[16]  R. C. N. Pilawa-Podgurski,et al.  Submodule Integrated Distributed Maximum Power Point Tracking for Solar Photovoltaic Applications , 2013, IEEE Transactions on Power Electronics.

[17]  Dragan Maksimovic,et al.  Performance of Mismatched PV Systems With Submodule Integrated Converters , 2014, IEEE Journal of Photovoltaics.

[18]  K. Kesarwani,et al.  A comparative theoretical analysis of distributed ladder converters for sub-module PV energy optimization , 2012, 2012 IEEE 13th Workshop on Control and Modeling for Power Electronics (COMPEL).

[19]  Robert C. N. Pilawa-Podgurski,et al.  A distributed approach to MPPT for PV sub-module differential power processing , 2013, 2013 IEEE Energy Conversion Congress and Exposition.

[20]  Joseph Appelbaum,et al.  Shadow effect of adjacent solar collectors in large scale systems , 1979 .

[21]  Dragan Maksimovic,et al.  Performance of differential power-processing submodule DC-DC converters in recovering inter-row shading losses , 2015, 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC).

[22]  D. Maksimovic,et al.  Architectures and Control of Submodule Integrated DC–DC Converters for Photovoltaic Applications , 2013, IEEE Transactions on Power Electronics.