@inproceedings{GottschalkPflaumSchneideretal.2017, author = {Gottschalk, L. and Pflaum, D. and Schneider, S. and Schulze, Achim and Becker, F. and Queck, M. and H{\"u}ttl, B.}, title = {Evaluation of a compehensive IV- Outdoor Characterization Method for Photovoltaik Modules}, series = {Proceedings of the 33rd EU-PVSEC}, booktitle = {Proceedings of the 33rd EU-PVSEC}, year = {2017}, language = {en} } @inproceedings{WachterGottschalkSimmleretal.2016, author = {Wachter, M. and Gottschalk, L. and Simmler, M. and Schulze, Achim and Becker, F. and Sayala, M. and H{\"u}ttl, B.}, title = {Short-cicuit current measurement at clear-sky conditions on photovoltaik modules}, series = {Proceedings of the 32nd EU-PVSEC}, booktitle = {Proceedings of the 32nd EU-PVSEC}, year = {2016}, language = {en} } @inproceedings{KaiserSimmlerWachteretal.2015, author = {Kaiser, D. and Simmler, M. and Wachter, M. and Becker, F. and Sayala, M. and Kaden, T. and Schulze, Achim and H{\"u}ttl, B.}, title = {Concept for fast and precise PV Module Outdoor Characterization}, series = {Proceedings of the 31st EU-PVSEC}, booktitle = {Proceedings of the 31st EU-PVSEC}, year = {2015}, language = {en} } @inproceedings{SchulzeHuettlNeubertetal.2010, author = {Schulze, Achim and H{\"u}ttl, B. and Neubert, S. and Hund, B. and Luschitz, J. and Patzlaff, T.}, title = {2D Analysis of thin-film modules}, series = {Proceedings of the 25th EU-PVSEC}, booktitle = {Proceedings of the 25th EU-PVSEC}, year = {2010}, language = {en} } @inproceedings{SchneiderHuettlPflaumetal.2020, author = {Schneider, S. and H{\"u}ttl, B. and Pflaum, D. and Schnell, V. and Schulze, Achim}, title = {Freifeldcharakterisierung von PV-Anlagen im Rahmen des Projektes PV- FeldLab -ein Statusbericht-}, series = {3. Regenerative Energietechnik Konferenz in Nordhausen}, booktitle = {3. Regenerative Energietechnik Konferenz in Nordhausen}, publisher = {RET.con 2020}, address = {Nordhausen}, year = {2020}, abstract = {Das Projekt PV-FeldLab verfolgt das Ziel, ein umfassendes Konzept f{\"u}r eine messtechnisch sehr pr{\"a}zise elektrische Freifeld-Charakterisierung von PV-Generatoren zu entwickeln. Es beinhaltet eine optische Untersuchung mittels drohnengest{\"u}tzter Thermografie und eine genaue elektrische Charakterisierung von PV-Anlagen im Freifeld, auch bei r{\"a}umlicher Inhomogenit{\"a}t von Bestrahlungsst{\"a}rke, Temperatur und bei variablen Aufbauwinkeln von Modulen im Strang. Die Verkn{\"u}pfung der elektrischen und optischen Messdaten erlaubt eine effiziente Untersuchung von PV-Anlagen und erm{\"o}glicht eine Pr{\"a}zisierung von Ertragsanalysen. Dieser Bericht beschreibt den ersten Projektabschnitt, in welchem der Fokus vor allem auf der Initialisierung der messtechnischen Komponenten, sowie ersten Messungen und Analysen liegt.}, language = {de} } @inproceedings{SchneiderHuettlGerstenbergetal.2019, author = {Schneider, S. and H{\"u}ttl, B. and Gerstenberg, L. and Wesselak, V. and Voswinckel, S. and Schulze, Achim}, title = {PV-FeldLab -Feldlabor f{\"u}r Vorort-Leistungsbestimmungen und Alterungsidentifikation von Photovoltaikgeneratoren}, series = {2. Regenerative Energietechnik Konferenz in Nordhausen}, booktitle = {2. Regenerative Energietechnik Konferenz in Nordhausen}, publisher = {RET.com 2019}, address = {Nordhausen}, year = {2019}, abstract = {Ziel des Projektes ist es, ein Verfahren f{\"u}r elektrische Vorort-Leistungsanalysen von Photovoltaik (PV)-Anlagen zu entwickeln. Dazu werden die elektrischen Parameter von PV-Strings lokal und global mit Hilfe eines neuen Feldlaboransatzes mit Indoor-Laborgenauigkeit vermessen. Das neue Messverfahren ist normgerecht und wird helfen, die Standardisierung von Feldmessungen weiterzuentwickeln. Im Projekt werden bekannte Messmethoden der Photovoltaik, (IR-Thermografie, I-U-String-Messung, digitale Datenverarbeitung mittels Selbstreferenzierung) zu einem innovativen Gesamtkonzept synthetisch zusammengef{\"u}hrt. Die Entwicklung des Messverfahrens wird an speziell gealterten PV-Anlagen marktbestimmender Technologien (c-Si-, CdTe-, CIGS-Muster-PV-Anlagen) vorangetrieben. So wird das Verfahren auf Erkennung spezifischer Degradationsszenarien und marginaler quantitativer Parameterver{\"a}nderungen trainiert und gesch{\"a}rft}, language = {de} } @inproceedings{SchneiderPflaumGottschalketal.2018, author = {Schneider, S. and Pflaum, D. and Gottschalk, L. and Schulze, Achim and H{\"u}ttl, B.}, title = {Laborgenaue elektrische Charakterisierungen von PV-Modulen unter Feldbedingungen}, series = {1. Regenerative Energietechnik Konferenz in Nordhausen}, booktitle = {1. Regenerative Energietechnik Konferenz in Nordhausen}, publisher = {RET.con 2018}, address = {Nordhausen}, year = {2018}, abstract = {Outdoor-I-U-Messungen an Photovoltaik- (PV) - Modulen haben den Vorteil, dass Effekte wie „light soaking" oder „light-induced degradation" unter nat{\"u}rlichen Bedingungen untersucht werden k{\"o}nnen. Solche Outdoor-Analysen k{\"o}nnen unter Anwendung des Selbstreferenzierungsalgorithmus (SRA) die Zuverl{\"a}ssigkeit von Indoor-Flasher-Messungen erreichen. Dieses neue Konzept liefert I-UEigenschaften f{\"u}r wesentlich mehr Testbedingungen als vom Standard IEC 61853 gefordert und so k{\"o}nnen Schwachlichtkurven aller relevanten elektrischen I-U-Parameter f{\"u}r bestimmte Temperaturen erzeugt werden. Wir berichten {\"u}ber experimentelle Ergebnisse einer 6-t{\"a}gigen Outdoor-Messkampagne an D{\"u}nnschicht-PV-Modulen. Wir evaluieren dar{\"u}ber hinaus die M{\"o}glichkeiten, Temperaturkoeffizienten, STC- und NOCT-Daten zu bestimmen und I-U-Kennlinien als Basis f{\"u}r Fitting-Analysen abzuleiten. Abschließend wird die Genauigkeit der neuen Outdoor-Methode untersucht.}, language = {de} } @inproceedings{HuettlHeimfarthSchulzeetal.2012, author = {H{\"u}ttl, B. and Heimfarth, J.P. and Schulze, Achim and Schelhase, S. and Hafemeister, M. and Weiler, U. and Queck, M. and Patzlaff, T. and Bauer, M. and Becker, F.}, title = {Improved JV-Analysis on CdTe Dot Cells by Controlled Series Resistance}, series = {Proc. 27th European Photovoltaic Solar Energy Conference and Exhibition}, booktitle = {Proc. 27th European Photovoltaic Solar Energy Conference and Exhibition}, publisher = {27th European Photovoltaic Solar Energy Conference and Exhibition}, year = {2012}, abstract = {CdS/CdTe thin film solar technology is one of the most promising concepts to accomplish high efficiencies and low costs in mass production. Further knowledge about electric parameters, such as serial resistances and recombination losses, is needed in order to improve in a systematic approach the module efficiency. The basic tool for device evaluation is the JV-measurement (current density - voltage) under standard test conditions. JVmeasurements result in rather direct determination of electric parameters, and detailed JV-analysis in indirect determination of some more relevant electric parameters. For thin film solar cells the usual 2-diode model and the responsible equation can be reduced to a 1-diode model due to significant recombination processes in the space charge region. However, the fit results suffer on imprecision of derived recombination currents (Jrec), and series resistance (Rs), due to their ambiguousness in fit routine. Direct and precise access of Rs by measurements fails for CdTe, due to its significant dependency on illumination levels. In this work we present a new method for precise Rs and Jrec determination of CdTe cells.}, language = {en} } @inproceedings{HuettlWachterGottschalketal.2016, author = {H{\"u}ttl, B. and Wachter, M. and Gottschalk, L. and Schulze, Achim and Becker, F.}, title = {Self Reference Algorithm for Precise Outdoor Characterization of PV Modules}, series = {PV-Days Halle 2016}, booktitle = {PV-Days Halle 2016}, publisher = {PV-Days Halle 2016}, address = {Halle}, year = {2016}, abstract = {Outdoor or just on site analyzes of photovoltaic modules can offer some advantages in comparison to indoor Lab stud-ies. In this way the electrical performance is monitored and logged under natural operating conditions in full range of irradiation and temperature. The entirety of monitored IV data allows deriving low-light characteristics of electric parameters, temperature coefficients and root cause analysis for possible degradation. We apply so-called self-reference algorithm in order to increase the accuracy of analysis. The improved precision is due to application of effective acting irradiation and effective temperature instead of externally measured data. Effective irradiation is determined in self-referencing scheme: the short circuit current of the module is assigned to the irradiation.}, language = {en} } @inproceedings{WachterGottschalkSimmleretal.2016, author = {Wachter, M. and Gottschalk, L. and Simmler, M. and Schulze, Achim and Becker, F. and Sayala, M. and H{\"u}ttl, B.}, title = {Short Circuit Current Measurements at Clear-Sky Conditions on Photovoltaic Modules: Basic for a Reliable Self-Reference Algorithm}, series = {Proc. 32nd European Photovoltaic Solar Energy Conference and Exhibition (PVSEC)}, booktitle = {Proc. 32nd European Photovoltaic Solar Energy Conference and Exhibition (PVSEC)}, publisher = {32nd European Photovoltaic Solar Energy Conference and Exhibition (PVSEC)}, year = {2016}, abstract = {Outdoor or just on site analyzes of photovoltaic modules can offer some advantages in comparison to indoor Lab studies. In this way the electrical performance is monitored and logged under natural operating conditions in full range of irradiation and temperature. The entirety of monitored IV data allows deriving low-light characteristics of electric parameters, temperature coefficients and root cause analysis for possible degradation. We apply so-called self-reference algorithm in order to increase the accuracy of analysis. The improved precision is due to application of effective acting irradiation and effective temperature instead of externally measured data. Effective irradiation is determined in self-referencing scheme: the short circuit current of the module is assigned to the irradiation. This assignment has to be calibrated, preferably at standard test conditions for irradiation. In this contribution we demonstrate a process of precise measurement of Isc under clear-sky outdoor conditions and the determination of the short circuit current for STC. The measurement method avoids errors by spectral deviations with respect to AM 1.5G spectrum, by optical reflection losses for high angles of incidence and errors by high albedo impact. In particular we investigate comparatively a CdTe module under outdoor conditions and by means a calibrated indoor Lab flasher.}, language = {en} } @inproceedings{SchneiderDaumeNeumeyeretal.2021, author = {Schneider, S. and Daume, D. and Neumeyer, T. and Pflaum, D. and Schulze, A. and H{\"u}ttl, B.}, title = {Charakterisierung von PV-Generatoren bei variabler Bestrahlungsst{\"a}rke und Temperatur - Zwischenbericht zum Projekt PV-FeldLab}, series = {Tagungsband der 4. Regenerativen Energietechnik Konferenz (RET.Con)}, booktitle = {Tagungsband der 4. Regenerativen Energietechnik Konferenz (RET.Con)}, isbn = {978-3-940820-17-4}, pages = {86 -- 95}, year = {2021}, language = {de} } @inproceedings{DaumeSchulzeSchneideretal.2021, author = {Daume, D. and Schulze, A. and Schneider, S. and Neumeyer, T. and Beck, T. and Steinbach, S. and H{\"u}ttl, B.}, title = {Accurate Short-Circuit Current Measurements on Photovoltaic Modules - Challenges for On-site Outdoor Determinations}, series = {Proc. of 38th European Photovoltaic Solar Energy Conference and Exhibition (PVSEC), 4AV.2.6., September 2021, Lissabon}, booktitle = {Proc. of 38th European Photovoltaic Solar Energy Conference and Exhibition (PVSEC), 4AV.2.6., September 2021, Lissabon}, year = {2021}, language = {en} } @inproceedings{SchelerDaumeSojitraetal.2022, author = {Scheler, M. and Daume, D. and Sojitra, D. and Neumeyer, T. and Steinbach, S. and Beck, T. and Schulze, A. and H{\"u}ttl, B.}, title = {Precise On-Site Power Analysis of Photovoltaic Arrays by Self-Reference Algorithm}, series = {Proceedings of the 8th World Conference on Photovoltaic Energy Conversion}, booktitle = {Proceedings of the 8th World Conference on Photovoltaic Energy Conversion}, pages = {4}, year = {2022}, abstract = {To detect degradation of photovoltaic systems at an early stage, precise performance determinations are essential. Current-voltage measurements on single modules in indoor labs under well-defined conditions are state-of-the-art. However, this method causes a logistical and economic effort. On-site measurements reduce the effort but are prone to error because of poorly determinable test conditions: The detected temperature on the backside of modules as well as the irradiance detected by pyranometer in tilted module plane usually differs from the actual operating conditions. In consequence, the accuracy of measured current-voltage characteristics is poor. A precise on-site power determination is achieved by a self-reference algorithm. Improvements by self-referencing are not achieved by correcting the raw electrical data, but by replacing the measured test conditions (temperature and irradiance) with effective data. These effective values correspond better to the actual module irradiance and temperature values. Furthermore, precise power determination of photovoltaic arrays requires to identify and exclude emporarily deformed current-voltage curves from consideration, as it can arise from non-uniform irradiation within array like shading. In this paper, the application of a digital curve filter is reported and performance determinations by a self-reference algorithm are demonstrated on a photovoltaic array. We review and discuss the measurement concept in terms of its ease of use. … }, language = {en} }