NEWS ON PV MODULE TESTING AT LEEE-TISO

The photovoltaic modules performances are evaluated from their I-V characteristic. We present in this article the I-V measurement bench that we have set up at UDES in order to characterize the photovoltaic modules under natural conditions. We present, first, the method used for modeling PV module that allows us to simulate the I-V curve under a given conditions of illumination and temperature. We then describe the bench measurement focusing on the power MOSFETs electronic load that we realized. As an example, the plot of an I-V characteristic of a c-Si photovoltaic module got with our testing bench at a given operating conditions and translated to STC conditions are in good agreement with the one supplied by the manufacturer with a few correction made.

2019

The paper presents results from an inter laboratory comparison (ILC) of crystalline silicon PV module performance measurements from three different institutions within South Africa. The analysis quantifies the differences in power, current, and voltage measurements and compares power to the stated uncertainties for the measurements. The paper also explains the basics of PV module performance measurements, the link to PV module nameplate ratings, and describes the sources of uncertainty in the measurements. The results of the 2019 ILC I-V measurements among three South African institutions show differences of +/-2.0% or less for maximum power measurements of crystalline PV modules, relative to the CSIR results. These differences are within the stated uncertainty for the measurements but greater than the +/-0.5% differences among international reference labs reported in a 2017.

Photovoltaic modules based on the relatively high efficiency crystalline technology are gaining importance in the photovoltaic market. Improving module performance is driven by a focus on lifetime yields and requirements of spaceconstraints sites. The materials used not only in thin film technologies but also crystalline pose problems in terms of measuring how much power is generated under STC. The fact that the modules power rates vary depends both on the amount of time they have been exposed to the sun and on their history of sunlight exposure in order to know the current state of the module. It is necessary to determine an easily accomplishable testing method that ensures the repeatability of the measurements of the power generated. This is essential because in order to have a reliable sample of the PV module population of a large PV plant, a huge no of modules must be measured. This paper shows different tests performed on different commercial crystalline PV modules both multi and mono, in order to find the best way to obtain measurements. A correlation was tested between sun exposure and power measured. A method for obtaining indoor measurements that takes periods of sunlight exposure into account is proposed. Also, temperature and irradiance coefficients were also determined for different technologies in order to obtain accurate measurements. Tests are operated in outdoor exposure and natural sunlight located in Gurgaon Region of Haryana (India) as specific composite climate environment, characterized by high irradiation and temperature levels.

Sādhanā, 2020

The appropriate measurement of solar power output plays a critical role in the performance analysis of any solar power plant or a photovoltaic array. The performance under standard test conditions (STC), as mentioned by the manufacturers, is seldom attained as measurements of a PV module/array are done in outdoor terms. To evaluate the efficiency of performance, a photovoltaic module/array accurately, an on-line characterization of such photovoltaic (PV) setups at non-standard test conditions (NSTC) is always necessary. In the backdrop of the absence of reliable and competitively priced PV module characterization systems, a smart, digital and portable test setup seem to be highly significant, and such a model has been developed and analyzed in this work. This system uses supercapacitors as the load to the PV module under test. At present, such characterizations are carried out using imported devices, which cost around INR 200-300 thousand. The system so developed will cost around INR 30 thousand and is aimed at import substitutions of such measurement devices. This is very important with regard to field installations testing and will also be of extreme help to researchers in the laboratories, who require all cannot use extensive testing and costly imported instruments. Proper attention has been paid in this work to determine the suitability of the method concerning I-V plotting time and accuracy. Thus it becomes imperative that the quality of the new PV metrology be verified experimentally and duly validated to instill confidence among the users. A detailed investigation regarding the quality of measurements has been carried out, taking into consideration the effect of a wide range of climatic variations. It has been found that these values are consistently in good agreement with the results obtained at the standard Electronics Regional Test Laboratory (ERTL Govt. Of India) test setup. Statistical analysis of the PV measurements is ensured by regression analysis (RA) of the respective electrical parameters and the standard deviation (SD) of fill factor (FF) values. Experimental evaluation of quality parameters like Fill-Factor (FF) has yielded satisfactory ranges of 70% to 79% for FF. Elaborate regression analysis (RA) of principal PV parameters has yielded consistently high values exceeding 99%. At this time, when India is planning to install large-scale PV plants, there is a significant need to measure the electrical parameters of PV modules of different technologies and, after that, choose the appropriate one for optimum performance in a specific region.

The purpose of this paper is to present the activity of the MPVT (Multi-Purpose PV Module Tester) project funded by the Innovation Promotion Agency (CTI) of the Swiss Confederation. The aim of the project is to develop an extremely versatile measurement equipment for the indoor testing of PV modules by upgrading and integrating new functionalities into an existing pulsed solar-simulator based IV measurement setup. The newly developed MPVT setup will be able to realize IV measurements at standard test conditions, temperature coefficients (TCO's) and measurement at different irradiance levels. In addition, a setup to measure spectral response (SR) of large-area module will be implemented in the system. The MPVT system will be adapted to the needs of the different PV technologies present today on the market, which require a larger flexibility in terms of electrical measurement conditions (high-voltage/low-current thin film PV and high-current/low-voltage c-Si technologies). Moreover, traditional or alternative solutions will be implemented to overcome problems-related to the short duration of the light pulse-which some technologies may encounter when performing power measurements with flashers, as for example, high efficient c-Si modules, which are characterized by high cell capacitances.

2015

Performance of a PV installation depends critically on the modules behaviour. That is the reason why a good estimation of energy production of a PV installation relies not only on the goodness of the module power characterization at standard test conditions, but also on the goodness of the characterisation of the module behaviour related to the variation of irradiance and temperature. So, it is closer to the reality running a simulation exercise of energy production with the actual values measured outdoors than with the values obtained from datasheets. This paper presents a device specifically implemented to measure outdoors the power of modules at standard test conditions, as well as their efficiency variation with irradiance and their temperature coefficients. Results of measurements with this device are also reported.

2010 35th IEEE Photovoltaic Specialists Conference, 2010

A review of the performance characterization of photovoltaic modules is given, that charts the progress made in the European research project 'PV-Performance' as well as other work carried out in Europe. The aim is to illustrate the measurement and prediction accuracy of energy delivery. It is shown that direct inter-comparisons of PV modules may have as much as 6.5% uncertainty in the comparability between modules and that any difference much lower than this is not a meaningful conclusion. A significant contribution to this is the determination of the rated power of the modules chosen for the inter-comparison and the lack of statistical numbers. The rated power is also important in the context of modeling the performance and thus must be as accurately as somewhat possible. It is shown that the uncertainties of the calibration laboratories are not borne out by round robin inter-comparisons and further work is needed in this field. Uncertainties for wafer-based devices are shown to be in a range of ±3%, while different thin film technologies may have higher uncertainties. It is shown that even simple modeling approaches are good enough to predict PV performance to within the measurement accuracy of most datasets.

Journal of Solar Energy Engineering, 2006

Computer simulation tools used to predict the energy production of photovoltaic systems are needed in order to make informed economic decisions. These tools require input parameters that characterize module performance under various operational and environmental conditions. Depending upon the complexity of the simulation model, the required input parameters can vary from the limited information found on labels affixed to photovoltaic modules to an extensive set of parameters. The required input parameters are normally obtained indoors using a solar simulator or flash tester, or measured outdoors under natural sunlight. This paper compares measured performance parameters for three photovoltaic modules tested outdoors at the National Institute of Standards and Technology (NIST) and Sandia National Laboratories (SNL). Two of the three modules were custom fabricated using monocrystalline and silicon film cells. The third, a commercially available module, utilized triple-junction amorpho...

2003

This paper describes the first results of development of user-friendly tools and models for predicting and evaluating performances of photovoltaic modules under actual field conditions. First is described the development of model for the photovoltaic module that uses the mono and poly-crystaline tecnologies. A workhenck consisting of a micro-controller load simulator and a data acquisition system for the charactertization of photovoltaic modules under specific operational conditions is plesented. The models parameters are then estimated and the simulation is carried out. These tools enable the field engineer to predict system (and component) performance for known operational conditions before actually deploying the system for its intended application.