scholarly journals A Non-Invasive Procedure for Estimating the Exponential Model Parameters of Bypass Diodes in Photovoltaic Modules

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 303 ◽  
Author(s):  
Jeisson Vélez-Sánchez ◽  
Juan Bastidas-Rodríguez ◽  
Carlos Ramos-Paja ◽  
Daniel González Montoya ◽  
Luz Trejos-Grisales

Bypass diodes (BDs) present in photovoltaic (PV) modules are represented by the exponential model, which requires two parameters: the inverse-saturation current ( I s a t , d b ) and the ideality factor ( η d b ). However, it is difficult to estimate those parameters since the terminals of the BDs are not isolated, hence there is only access to the series connection of the module BDs. This problem must be addressed since inaccurate BDs parameters could produce errors in the reproduction of the current-voltage (I-V) curves of commercial PV modules, which lead to wrong predictions of the power production. This paper proposes a non-invasive procedure to estimate I s a t , d b and η d b of the bypass diodes present in a PV module using two experimental I-V curves. One I-V curve is measured completely covering the submodule of the module whose BD will be parameterized; while the other I-V curve is measured without any shadow on the module. From those curves, the I-V curve of the BD is estimated and I s a t , d b and η d b are calculated by solving a system of two nonlinear equations. The proposed procedure is validated through simulations and experimental results considering a commercial PV module formed by three submodules, where the estimation errors in the reproduction of the BD I-V curve are less than 1% in the simulations and less than 10% in the experiments.

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ju-Hee Kim ◽  
Jongsung Park ◽  
Donghwan Kim ◽  
Nochang Park

The corrosion of 62Sn36Pb2Ag solder connections poses serious difficulties for outdoor-exposed photovoltaic (PV) modules, as connection degradation contributes to the increase in series resistance (RS) of PV modules. In this study, we investigated a corrosion mitigation method based on the corrosion mechanism. The effect of added sacrificial metal on the reliability of PV modules was evaluated using the oxidation-reduction (redox) reaction under damp heat (DH) conditions. Experimental results after exposure to DH show that the main reason for the decrease in power was a drop in the module’s fill factor. This drop was attributed to the increase ofRS. The drop in output power of the PV module without added sacrificial metal is greater than that of the sample with sacrificial metal. Electroluminescence and current-voltage mapping analysis also show that the PV module with sacrificial metal experienced less degradation than the sample without sacrificial metal.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. Webber ◽  
E. Riley

Variations in photovoltaic (PV) module current-voltage curves result in a power loss in PV arrays often referred to as mismatch loss (MML). As a means of reducing MML, newly fabricated PV modules are sorted to meet a set tolerance for variation in overall maximum power output with respect to a given module’s rated power. Starting with flash test data sets for two different polycrystalline PV modules and a simulated sorting procedure, Monte Carlo techniques were used to generate a large number of artificial PV arrays. The MMLs for each of these arrays were then calculated to assess the sorting procedure’s ability to reduce MML. Overall MMLs were quite small (0.001–0.01%). Sorting by Imp resulted in the most consistent MML reductions. Sorting by Vmp yielded insignificant results. Sorting by Pmp yielded significant MML reduction in only one of the two PV module data sets. Analysis was conducted to quantify if additional sorting on top of what both manufacturers had already done would make economic sense. Based on high level economic analysis, it appears that additional sorting yields little economic gain; however, this is highly dependent upon manufacturer sorting cost.


Author(s):  
Heangwoo Lee ◽  
Xiaolong Zhao ◽  
Janghoo Seo

Recent studies on light shelves found that building energy efficiency could be maximized by applying photovoltaic (PV) modules to light shelf reflectors. Although PV modules generate a substantial amount of heat and change the consumption of indoor heating and cooling energy, performance evaluations carried out thus far have not considered these factors. This study validated the effectiveness of PV module light shelves and determined optimal specifications while considering heating and cooling energy savings. A full-scale testbed was built to evaluate performance according to light shelf variables. The uniformity ratio was found to improve according to the light shelf angle value and decreased as the PV module installation area increased. It was determined that PV modules should be considered in the design of light shelves as their daylighting and concentration efficiency change according to their angles. PV modules installed on light shelves were also found to change the indoor cooling and heating environment; the degree of such change increased as the area of the PV module increased. Lastly, light shelf specifications for reducing building energy, including heating and cooling energy, were not found to apply to PV modules since PV modules on light shelf reflectors increase building energy consumption.


2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Vandana Jha ◽  
Uday Shankar Triar

This paper proposes an improved generalized method for evaluation of parameters, modeling, and simulation of photovoltaic modules. A new concept “Level of Improvement” has been proposed for evaluating unknown parameters of the nonlinear I-V equation of the single-diode model of PV module at any environmental condition, taking the manufacturer-specified data at Standard Test Conditions as inputs. The main contribution of the new concept is the improvement in the accuracy of values of evaluated parameters up to various levels and is based on mathematical equations of PV modules. The proposed evaluating method is implemented by MATLAB programming and, for demonstration, by using the values of parameters of the I-V equation obtained from programming results, a PV module model is build with MATLAB. The parameters evaluated by the proposed technique are validated with the datasheet values of six different commercially available PV modules (thin film, monocrystalline, and polycrystalline) at Standard Test Conditions and Nominal Operating Cell Temperature Conditions. The module output characteristics generated by the proposed method are validated with experimental data of FS-270 PV module. The effects of variation of ideality factor and resistances on output characteristics are also studied. The superiority of the proposed technique is proved.


2004 ◽  
Vol 27 (2) ◽  
pp. 61-67
Author(s):  
S. Dib ◽  
C. Salame ◽  
N. Toufik ◽  
A. Khoury ◽  
F. Pélanchon ◽  
...  

A new method for the extraction of junction parameters from a description of the current–voltage characteristic is developed. A simulation is performed and a high accuracy is obtained for the determination of the singleexponential model parameters. The method is easy to implement in a control process for device characterization. An application, achieved to observe the degradation of the emitter–base junction of a bipolar transistor during an aging experiment, shows that the evolutions of the single exponential model parameters versus time introduce a means for degradation quantification.


Author(s):  
Nsed Ayip Akonjom ◽  
John Iyang Umuji ◽  
Ukoette Jeremiah Ekah

This central idea of this research is to investigate how voltage, current, power output and efficiency of polycrystalline photovoltaic (PV) modules installed in a Guinea Savanna and Mangrove Swamp is affected by temperature, relative humidity and irradiance. The study locations are Calabar (mangrove swamp) and Ogoja (guinea savanna), in Cross River State, Nigeria. Two polycrystalline PV modules of exact specification mounted on a platform one-metre-high above the ground were used. A digital solar power meter (SM206) and a digital solar flux meter (MS 6616) was used to monitor and measure solar power and solar flux reaching the PV modules. A digital hygrometer and thermometer (KT-908) were used to monitor and measure the relative humidity and ambient temperature level at the height of installation and a digital multimeter (M880C+) accompanied with a temperature sensor was used to monitor voltage, current and panel temperature values from the modules. Analysis of the collected data reveals that the efficiency of the modules were not constant throughout the day. However, a higher voltage production and efficiency level was obtained for the PV module installed in Ogoja than that installed in Calabar under their respective levels of relative humidity, temperature and irradiance.


2019 ◽  
Vol 9 ◽  
pp. 59-69
Author(s):  
Alok Dhaundiyal ◽  
Divine Atsu

This paper presents the modeling and simulation of the characteristics and electrical performance of photovoltaic (PV) solar modules. Genetic coding is applied to obtain the optimized values of parameters within the constraint limit using the software MATLAB. A single diode model is proposed, considering the series and shunt resistances, to study the impact of solar irradiance and temperature on the power-voltage (P-V) and current-voltage (I-V) characteristics and predict the output of solar PV modules. The validation of the model under the standard test conditions (STC) and different values of temperature and insolation is performed, as well as an evaluation using experimentally obtained data from outdoor operating PV modules. The obtained results are also subjected to comply with the manufacturer’s data to ensure that the proposed model does not violate the prescribed tolerance range. The range of variation in current and voltage lies in the domain of 8.21 – 8.5 A and 22 – 23 V, respectively; while the predicted solutions for current and voltage vary from 8.28 – 8.68 A and 23.79 – 24.44 V, respectively. The measured experimental power of the PV module estimated to be 148 – 152 W is predicted from the mathematical model and the obtained values of simulated solution are in the domain of 149 – 157 W. The proposed scheme was found to be very effective at determining the influence of input factors on the modules, which is difficult to determine through experimental means.


2018 ◽  
Vol 8 (6) ◽  
pp. 3570-3575
Author(s):  
E. V. Palconit ◽  
M. L. S. Abundo

An electric boat system as a pilot study for the electric ferry was designed and field-tested in Samal Island, Philippines, to verify sustainability for inter-island transport. This pilot study uses 4.5m monohull with a displacement weight of 343kg. During the experiment, two cases were compared: in the first case the boat was powered solely with batteries and in the other case with the aid of photovoltaic (PV) modules. For the first case, 24V electric propulsion was driven by two 12V, 100Ah batteries, which resulted to a navigational range of around 18, 16 and 15 trips with energy consumption of 111.64Wh, 117.19Wh and 123.92Wh respectively. In the second case, the photovoltaic modules were attached on the boat to supplement the PV used while on sail. Results in the second case showed that PV module supplemented energy was about to 13.4%, 26.8% and 38.7% using three different speeds like 3.18, 3.32 and 3.84knots and the navigational range extended to 4km, 1km, and 14.4km respectively. Therefore, the electric boat with the aid of PV module answers the problem in the energy management system that deals with the sustainability of the system in the inter-island transport in Philippines.


Author(s):  
C. Calò ◽  
A. Lay-Ekuakille ◽  
P. Vergallo ◽  
C. Chiffi ◽  
A. Trotta ◽  
...  

One of the most important aspects of photovoltaic modules is reliability for future uses, that is, a certain module will last certain number of years in use (generally 30 or 35 years). Reliability yields from excellent qualification tests on photovoltaic (PV) modules. Testing for reliability identifies unknown failure mechanisms and whether modules are susceptible to known failure mechanisms. This paper illustrates techniques of outdoor measurements and qualification characterization to know PV module conditions for commercial uses. Matrix methods are used for energy prediction. Failure material tests, using digital imaging and thermography, have also been conducted.


2019 ◽  
Vol 11 (22) ◽  
pp. 6234 ◽  
Author(s):  
Hyeonwook Park ◽  
Sungho Chang ◽  
Sanghwan Park ◽  
Woo Kyoung Kim

The outdoor performance of n-type bifacial Si photovoltaic (PV) modules and string systems was evaluated for two different albedo (ground reflection) conditions, i.e., 21% and 79%. Both monofacial and bifacial silicon PV modules were prepared using n-type bifacial Si passivated emitter rear totally diffused cells with multi-wire busbar incorporated with a white and transparent back-sheet, respectively. In the first set of tests, the power production of the bifacial PV string system was compared with the monofacial PV string system installed on a grey concrete floor with an albedo of ~21% for approximately one year (June 2016–May 2017). In the second test, the gain of the bifacial PV string system installed on the white membrane floor with an albedo of ~79% was evaluated for approximately ten months (November 2016–August 2017). During the second test, the power production by an equivalent monofacial module installed on a horizontal solar tracker was also monitored. The gain was estimated by comparing the energy yield of the bifacial PV module with that of the monofacial module. For the 1.5 kW PV string systems with a 30° tilt angle to the south and 21% ground albedo, the year-wide average bifacial gain was determined to be 10.5%. An increase of the ground albedo to 79% improved the bifacial gain to 33.3%. During the same period, the horizontal single-axis tracker yielded an energy gain of 15.8%.


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