A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading

S. Essakiappan, H. S. Krishnamoorthy, P. Enjeti, Robert Balog, Shehab Ahmed

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Citations (Scopus)

Abstract

In this paper, a new control strategy for megawatt scale multilevel photovoltaic (PV) inverters under partial shading is proposed. In the proposed system, the photovoltaic arrays are divided into zones and each zone is connected to DC to AC inverter. The DC to AC inverters of multiple zones are connected in series to form the required medium voltage and transfer power to the grid. In such a system where all zones are uniformly illuminated, the output voltage vectors of all the inverters are of equal magnitude and in phase with each other. However, under partial shading, the output voltage magnitude and phase angles of individual DC to AC inverters need to be adjusted in such a way that the available real power is transferred to the grid and the power factor of the overall system is as close to unity as possible. A control strategy is developed to operate the series connected multilevel inverter configuration under partial shading, by continuously monitoring the real and reactive powers supplied by each inverter. The developed strategy does not require a central controller and/or communications between the various DC to AC inverter blocks. The proposed control strategy is simulated for a 6.6 kV, three phase utility scale PV system rated at 5 MW.

Original languageEnglish
Title of host publicationProceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012
Pages336-343
Number of pages8
DOIs
Publication statusPublished - 2012
Event2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012 - Aalborg, Denmark
Duration: 25 Jun 201228 Jun 2012

Other

Other2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012
CountryDenmark
CityAalborg
Period25/6/1228/6/12

Fingerprint

Electric inverters
Electric potential
Multiple zones
Reactive power
Controllers
Monitoring
Communication

Keywords

  • Grid integration
  • medium voltage
  • partial shading
  • photovoltaic
  • series connected inverters

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Cite this

Essakiappan, S., Krishnamoorthy, H. S., Enjeti, P., Balog, R., & Ahmed, S. (2012). A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading. In Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012 (pp. 336-343). [6254023] https://doi.org/10.1109/PEDG.2012.6254023

A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading. / Essakiappan, S.; Krishnamoorthy, H. S.; Enjeti, P.; Balog, Robert; Ahmed, Shehab.

Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012. 2012. p. 336-343 6254023.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Essakiappan, S, Krishnamoorthy, HS, Enjeti, P, Balog, R & Ahmed, S 2012, A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading. in Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012., 6254023, pp. 336-343, 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012, Aalborg, Denmark, 25/6/12. https://doi.org/10.1109/PEDG.2012.6254023
Essakiappan S, Krishnamoorthy HS, Enjeti P, Balog R, Ahmed S. A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading. In Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012. 2012. p. 336-343. 6254023 https://doi.org/10.1109/PEDG.2012.6254023
Essakiappan, S. ; Krishnamoorthy, H. S. ; Enjeti, P. ; Balog, Robert ; Ahmed, Shehab. / A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading. Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012. 2012. pp. 336-343
@inproceedings{ccc1a90763614323ad08607e65548daf,
title = "A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading",
abstract = "In this paper, a new control strategy for megawatt scale multilevel photovoltaic (PV) inverters under partial shading is proposed. In the proposed system, the photovoltaic arrays are divided into zones and each zone is connected to DC to AC inverter. The DC to AC inverters of multiple zones are connected in series to form the required medium voltage and transfer power to the grid. In such a system where all zones are uniformly illuminated, the output voltage vectors of all the inverters are of equal magnitude and in phase with each other. However, under partial shading, the output voltage magnitude and phase angles of individual DC to AC inverters need to be adjusted in such a way that the available real power is transferred to the grid and the power factor of the overall system is as close to unity as possible. A control strategy is developed to operate the series connected multilevel inverter configuration under partial shading, by continuously monitoring the real and reactive powers supplied by each inverter. The developed strategy does not require a central controller and/or communications between the various DC to AC inverter blocks. The proposed control strategy is simulated for a 6.6 kV, three phase utility scale PV system rated at 5 MW.",
keywords = "Grid integration, medium voltage, partial shading, photovoltaic, series connected inverters",
author = "S. Essakiappan and Krishnamoorthy, {H. S.} and P. Enjeti and Robert Balog and Shehab Ahmed",
year = "2012",
doi = "10.1109/PEDG.2012.6254023",
language = "English",
isbn = "9781467320238",
pages = "336--343",
booktitle = "Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012",

}

TY - GEN

T1 - A new control strategy for megawatt scale multilevel photovoltaic inverters under partial shading

AU - Essakiappan, S.

AU - Krishnamoorthy, H. S.

AU - Enjeti, P.

AU - Balog, Robert

AU - Ahmed, Shehab

PY - 2012

Y1 - 2012

N2 - In this paper, a new control strategy for megawatt scale multilevel photovoltaic (PV) inverters under partial shading is proposed. In the proposed system, the photovoltaic arrays are divided into zones and each zone is connected to DC to AC inverter. The DC to AC inverters of multiple zones are connected in series to form the required medium voltage and transfer power to the grid. In such a system where all zones are uniformly illuminated, the output voltage vectors of all the inverters are of equal magnitude and in phase with each other. However, under partial shading, the output voltage magnitude and phase angles of individual DC to AC inverters need to be adjusted in such a way that the available real power is transferred to the grid and the power factor of the overall system is as close to unity as possible. A control strategy is developed to operate the series connected multilevel inverter configuration under partial shading, by continuously monitoring the real and reactive powers supplied by each inverter. The developed strategy does not require a central controller and/or communications between the various DC to AC inverter blocks. The proposed control strategy is simulated for a 6.6 kV, three phase utility scale PV system rated at 5 MW.

AB - In this paper, a new control strategy for megawatt scale multilevel photovoltaic (PV) inverters under partial shading is proposed. In the proposed system, the photovoltaic arrays are divided into zones and each zone is connected to DC to AC inverter. The DC to AC inverters of multiple zones are connected in series to form the required medium voltage and transfer power to the grid. In such a system where all zones are uniformly illuminated, the output voltage vectors of all the inverters are of equal magnitude and in phase with each other. However, under partial shading, the output voltage magnitude and phase angles of individual DC to AC inverters need to be adjusted in such a way that the available real power is transferred to the grid and the power factor of the overall system is as close to unity as possible. A control strategy is developed to operate the series connected multilevel inverter configuration under partial shading, by continuously monitoring the real and reactive powers supplied by each inverter. The developed strategy does not require a central controller and/or communications between the various DC to AC inverter blocks. The proposed control strategy is simulated for a 6.6 kV, three phase utility scale PV system rated at 5 MW.

KW - Grid integration

KW - medium voltage

KW - partial shading

KW - photovoltaic

KW - series connected inverters

UR - http://www.scopus.com/inward/record.url?scp=84866940764&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84866940764&partnerID=8YFLogxK

U2 - 10.1109/PEDG.2012.6254023

DO - 10.1109/PEDG.2012.6254023

M3 - Conference contribution

SN - 9781467320238

SP - 336

EP - 343

BT - Proceedings - 2012 3rd IEEE International Symposium on Power Electronics for Distributed Generation Systems, PEDG 2012

ER -