@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{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} }