Analysis of mismatch and shading effects in a photovoltaic array using different technologies

In this paper, we analyze the performance of a photovoltaic array implemented in the Universidad Politécnica de Valencia which consists of modules of different technologies and power, connected in series, in order to quantify the energy losses due to mismatch and the effect of the shadows. To do this, the performance of the modules was measured in operation under ambient conditions with field measurement equipment (AMPROBE Solar Analyzer, Solar - 4000), which allows the extrapolation of measures to standard conditions STC. For the data validation, measures under controlled conditions were taken to some modules in the flash test laboratory of the Institute of Energy Technology ITE of Valencia in Spain. Subsequently the array curves measured were validated with a photovoltaic array model developed in MATLAB-Simulink for the same conditions and technologies. The results of this particular array are lost up to 20% of the energy supplied due to the modules mismatch. The study shows the curves and the energy loss due to shadows modules. This result opens scenarios for conceivable modifications to the PV field configurations today, chosen during the design stage and unchangeable during the operating stage; and gives greater importance to the energy loss by mismatch in the PV arrayGuerrero, J.; Munoz, Y.; Ibañez Escobar, F.; Ospino, A. (2014). Analysis of mismatch and shading effects in a photovoltaic array using different technologies. IOP Conference Series: Materials Science and Engineering. 59:1-9. doi:10.1088/1757-899X/59/1/012007S1959KAUSHIKA, N., & RAI, A. (2007). An investigation of mismatch losses in solar photovoltaic cell networks. Energy, 32(5), 755-759. doi:10.1016/j.energy.2006.06.017Moschitta, A., Damiani, A., & Carbone, P. (2012). A simple and accurate model for predicting mismatch effects in Photovoltaic Arrays. 2012 IEEE International Energy Conference and Exhibition (ENERGYCON). doi:10.1109/energycon.2012.6348264Spertino, F., & Akilimali, J. S. (2009). Are Manufacturing $I$– $V$ Mismatch and Reverse Currents Key Factors in Large Photovoltaic Arrays? IEEE Transactions on Industrial Electronics, 56(11), 4520-4531. doi:10.1109/tie.2009.2025712ALONSOGARCIA, M., RUIZ, J., & CHENLO, F. (2006). Experimental study of mismatch and shading effects in the – characteristic of a photovoltaic module. Solar Energy Materials and Solar Cells, 90(3), 329-340. doi:10.1016/j.solmat.2005.04.02

A new modified Inc-Cond MPPT technique and its testing in a whole PV simulator under PSC

In this paper a new modified Inc-Cond MPPT technique able to lead PV plants to work in the real MPP (Maximum Power Point) under PSC (Partial Shading Condition) is proposed. The new Inc-Cond MPPT technique working principle is fully explained, discussed and then successfully tested in a whole and reliable PV simulator conceived and set-up by the Authors in order to test and compare several new MPPT algorithms. The simulation results show that the proposed Inc-Cond MPPT technique is able to successfully lead the PV plant to work in the real MPP both in the cases of instantaneous and gradual changing of shading and of temperature conditions

A device for PV modules I-V characteristic detection

In this paper an electronic load suitable for the PV module I-V characteristic curve fast detection is presented. This device is designed in agreement with the IEC 82 Techinical Committee Standard since it allows the detection of the characteristic starting from voltage values even lower than 3% of the PV module open circuit voltage. The device main features are short time characteristc detection (2 s), limited ripple of the detected characteristic and low cost. Its validation is carried out by comparing measured data with data from simulations. Simulations are carried out considering two different commercial PV modules and by implementing in Matlab-Simulink environment the four lumped parameters PV cell mathematical model. This comparison sets the device is very reliable. Thanks to the device properties, the device allows the execution of experimental surveys directly on the premises, before the plant installation, optimizing the plants efficiency

Energy and network models for the intelligent control of distributed systems

This paper presents detailed energy and network models for the intelligent control of a distributed system which also comprises power generation from renewables. The two models provide interactive energy monitoring, intelligent control and power demand balancing at home, block and neighbor level. Particularly, it is here described how the energy model works and also details of how it has been validated are here given. Moreover, it is shown how the energy model simulation results are transferred to the network simulation software SynerGEE, set up by GL Noble Denton Industrial Services Ltd (UK), in order to fully perform network simulations

Una Via Elettrochimica per la Fabbricazione di Celle Solari a Semiconduttori Nanostrutturati

Nella memoria si presentano i risultati preliminari su un processo di crescita elettrochimica di materiali nanostrutturati mediante l\u2019impiego di stampi nanoporosi. Vengono quindi analizzate le possibili applicazioni del processo alla fabbricazione di semiconduttori nanostrutturati di interesse nel settore fotovoltaico, quali il CIGS, e le implicazioni dal punto di vista delle tecniche di caratterizzazione e di modellazione per dispositivi basati su tale tecnologia

Local DoS applications with micro wind generation systems

In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind flux canalization system and in the permanent magnet synchronous generator (PMSG) optimized for this specific purpose. In fact with the proposed system intends to search the best aerodynamic profile and electrical generator to ensure the slightest encumbrance and the lowest weight. For this purpose the traditional and classical tangential wind turbine design, equipped with large blades, is overturned in favour of the use of numerous little blades. A further peculiarity of the system is the expected increase of its efficiency thanks to the presence of the wind flux channelling system with the elimination of the part opposing the wind and thanks to the adoption of a specifically designed PMSG