On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes
Active anti-islanding schemes that are based on the injection of harmonic currents, such as the measurement of the impedance at a specific frequency or similar techniques, have been proposed for anti-islanding protection in photovoltaic (PV) systems due to their low impact on inverter active power,...
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MDPI AG
2018-08-01
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Series: | Energies |
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Online Access: | http://www.mdpi.com/1996-1073/11/9/2183 |
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author | Dionisis Voglitsis Fotis Valsamas Nick Rigogiannis Nick Papanikolaou |
author_facet | Dionisis Voglitsis Fotis Valsamas Nick Rigogiannis Nick Papanikolaou |
author_sort | Dionisis Voglitsis |
collection | DOAJ |
description | Active anti-islanding schemes that are based on the injection of harmonic currents, such as the measurement of the impedance at a specific frequency or similar techniques, have been proposed for anti-islanding protection in photovoltaic (PV) systems due to their low impact on inverter active power, their fast detection response in island, and reduced non-detection zone (NDZ). Integer multiples of the fundamental frequency as well as sub/inter-harmonics have both been used for the implementation of those schemes. Although utilization of sub/inter-harmonics present significant advantages, they also present significant limitations. This work investigates those limitations, particularly the ones that are caused by the parallel operation of multiple inverters. In addition, the distortion effect that is caused in the output current of the widely used PV microinverters with pseudo dc-link (PV Pdc-MICs) is discussed and thoroughly analyzed. It is concluded that when the injection is performed asynchronously (without communication among the inverters) sub/inter-harmonics are unsuitable for utilization under the parallel operation of multiple inverters. It is worth noting that a strategy is proposed in the current work that retains the effectiveness of the harmonic injection scheme under the injection of integer multiples of fundamental frequency. On the other hand, the distortion effect that is caused by the sub/inter-harmonics on PV Pdc-MICs output current, has been evaluated as insignificant when harmonics are used for anti-islanding purposes. Finally, the theoretical/mathematical outcomes of this work are supported by simulation and experimental results. |
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id | doaj.art-6d1fc0113d5742099db5005c6cf53ef0 |
institution | Directory Open Access Journal |
issn | 1996-1073 |
language | English |
last_indexed | 2024-04-11T22:05:11Z |
publishDate | 2018-08-01 |
publisher | MDPI AG |
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series | Energies |
spelling | doaj.art-6d1fc0113d5742099db5005c6cf53ef02022-12-22T04:00:44ZengMDPI AGEnergies1996-10732018-08-01119218310.3390/en11092183en11092183On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding PurposesDionisis Voglitsis0Fotis Valsamas1Nick Rigogiannis2Nick Papanikolaou3Department of Electrical and Computer Engineering, Democritus University of Thrace, ECE Campus Kimmeria, 67132 Xanthi, GreeceDepartment of Electrical and Computer Engineering, Democritus University of Thrace, ECE Campus Kimmeria, 67132 Xanthi, GreeceDepartment of Electrical and Computer Engineering, Democritus University of Thrace, ECE Campus Kimmeria, 67132 Xanthi, GreeceDepartment of Electrical and Computer Engineering, Democritus University of Thrace, ECE Campus Kimmeria, 67132 Xanthi, GreeceActive anti-islanding schemes that are based on the injection of harmonic currents, such as the measurement of the impedance at a specific frequency or similar techniques, have been proposed for anti-islanding protection in photovoltaic (PV) systems due to their low impact on inverter active power, their fast detection response in island, and reduced non-detection zone (NDZ). Integer multiples of the fundamental frequency as well as sub/inter-harmonics have both been used for the implementation of those schemes. Although utilization of sub/inter-harmonics present significant advantages, they also present significant limitations. This work investigates those limitations, particularly the ones that are caused by the parallel operation of multiple inverters. In addition, the distortion effect that is caused in the output current of the widely used PV microinverters with pseudo dc-link (PV Pdc-MICs) is discussed and thoroughly analyzed. It is concluded that when the injection is performed asynchronously (without communication among the inverters) sub/inter-harmonics are unsuitable for utilization under the parallel operation of multiple inverters. It is worth noting that a strategy is proposed in the current work that retains the effectiveness of the harmonic injection scheme under the injection of integer multiples of fundamental frequency. On the other hand, the distortion effect that is caused by the sub/inter-harmonics on PV Pdc-MICs output current, has been evaluated as insignificant when harmonics are used for anti-islanding purposes. Finally, the theoretical/mathematical outcomes of this work are supported by simulation and experimental results.http://www.mdpi.com/1996-1073/11/9/2183anti-islandingPV invertersMICmicroinverterharmonicssub-harmonicsinter-harmonics |
spellingShingle | Dionisis Voglitsis Fotis Valsamas Nick Rigogiannis Nick Papanikolaou On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes Energies anti-islanding PV inverters MIC microinverter harmonics sub-harmonics inter-harmonics |
title | On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes |
title_full | On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes |
title_fullStr | On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes |
title_full_unstemmed | On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes |
title_short | On the Injection of Sub/Inter-Harmonic Current Components for Active Anti-Islanding Purposes |
title_sort | on the injection of sub inter harmonic current components for active anti islanding purposes |
topic | anti-islanding PV inverters MIC microinverter harmonics sub-harmonics inter-harmonics |
url | http://www.mdpi.com/1996-1073/11/9/2183 |
work_keys_str_mv | AT dionisisvoglitsis ontheinjectionofsubinterharmoniccurrentcomponentsforactiveantiislandingpurposes AT fotisvalsamas ontheinjectionofsubinterharmoniccurrentcomponentsforactiveantiislandingpurposes AT nickrigogiannis ontheinjectionofsubinterharmoniccurrentcomponentsforactiveantiislandingpurposes AT nickpapanikolaou ontheinjectionofsubinterharmoniccurrentcomponentsforactiveantiislandingpurposes |