Equivalent Circuit Of Solar Cell Research Articles

Study on impedance spectroscopy based on dynamic equivalent circuit of solar cell

Study on impedance spectroscopy based on dynamic equivalent circuit of solar cell

Modelling and Simulation of Photovoltaic Systems Using MATLAB / Simulink

The use of renewable energy sources has increased rapidly today, and the easy availability of solar energy and its abundance in nature are one step ahead of other renewable energy sources. The rapid increase in the technological infrastructure, especially to obtain electricity from solar energy by photovoltaic (PV) method, has also accelerated the process of integrating PV systems into people's daily life. In this study, the solar cell model was obtained by using a solar cell equivalent circuit with Matlab Simulink and a 5.3 kW PV generator was designed using this structure. Also, the performance of the PV module has been analyzed under different temperature and solar irradiation conditions. Thanks to the developed model, it is aimed to use PV model generators with different technical features and different installed power more easily. Methodology in this project study was to create a circuit model of a solar cell in the Matlab Simulink program, modeling this model as a subsystem.

A Discrete Electrical Model for Photovoltaic Solar Cells—d1MxP

Solar cell equivalent circuit modelling is usually based on continuous I-V models, with a set of data obtained by analytical expressions. This work proposes an almost discrete novel mathematical method and correspondent electrical model, based on the I-V curve adjustment at every two adjacent points. It is based on the discretisation of any diode model behaviour, such as the 1M5P (also known as 1D5P) or the 1M7P (also known as 2D7P). For this reason, the model is named d1MxP, meaning that it is a discrete (d) model (1M) with x parameters (xP). The modelling methodology validation process uses experimental data already published in the literature. According to the presented results, the proposed method shows increased accuracy when compared to the 1M5P or 1M7P equivalent models. The accuracy on the maximum power point and fill factor determination is relevant, resulting in an improvement of up to 3.34% in the maximum power, up to 5.70% in its voltage and up to 8.20% in its current, for the analysed data. Furthermore, Fill Factor values, have variation from up to 35.98%. The temperature influence on the silicon solar cell is also analysed, to validate the results. The proposed method allows highly accurate curve fitting to the (experimental) points and consequently, to obtain a more accurate model to analyse the performance of solar cells under different conditions.

Estimation of Parameters of Different Equivalent Circuit Models of Solar Cells and Various Photovoltaic Modules Using Hybrid Variants of Honey Badger Algorithm and Artificial Gorilla Troops Optimizer

Parameters of the solar cell equivalent circuit models have a significant role in assessing the solar cells’ performance and tracking operational variations. In this regard, estimating solar cell parameters is a difficult task because cells have nonlinear current-voltage characteristics. Thus, a fast and accurate optimization algorithm is usually required to solve this engineering problem effectively. This paper proposes two hybrid variants of honey badger algorithm (HBA) and artificial gorilla troops optimizer (GTO) to estimate solar cell parameters. The proposed algorithms minimize the root mean square error (RMSE) between measurement and simulation results. In the first variant, GTO is used to determine the initial population of HBA, while in the second variant, HBA is used to determine the initial population of GTO. These variants can efficiently improve convergence characteristics. The proposed optimization algorithms are applied for parameter estimation of different equivalent circuit models of solar cells and various photovoltaic (PV) modules. Namely, the proposed algorithms test three solar cell equivalent models: single-diode, double-diode, and triple-diode equivalent circuit models. Different photovoltaic modules are investigated, such as the RadioTechnique Compelec (RTC) France solar cell, Solarex’s Multicrystalline 60 watts solar module (MSX 60), and the Photowatt, France solar panel (Photo-watt PWP 201). In addition, the applicability of the proposed optimization algorithms is verified using obtained results from a commercial solar module called Shell Monocrystalline PV module (SM55) with different irradiation and temperature levels. The good results of the proposed algorithms show that they can efficiently improve convergence speed and the accuracy of the obtained results than other algorithms used for parameter estimation of PV equivalent circuit models in the literature, particularly in terms of the values of the RMSE and statistical tests. In addition, the parameters estimated by the proposed methods fit the simulation data perfectly at different irradiance and temperature levels for the commercial PV module.

Accurate modeling and simulation of solar photovoltaic panels with simulink-MATLAB

A unique procedure to model and simulate a 36-cell-50 W solar panel using analytical methods has been developed. The generalized expression of solar cell equivalent circuit was validated and implemented, making no influential assumptions, under Simulink/MATLAB R2020a environment. The approach is based on extracting all the needed parameters by exploiting the available parameters from the data sheets of commercial PV panels and by estimating the slopes at both short-circuit and open-circuit conditions of the current–voltage characteristic, usually provided by most solar panels manufacturers under standard test conditions (STC). The effects of solar irradiance and temperature were both considered in the modeling. A system of coupled nonlinear simultaneous equations for diode saturation current, diode ideality factor, and series and shunt resistances has been solved. To accurately model the PV module used in our simulation and analysis, the needed temperature- dependent parameters have been extracted for the first time. At STC irradiance of 1000 W/m2, the modeled I-V curve was found identical to the experimental one which is provided by the solar panel manufacturer. The maximum power output of the PV module increases from 8.75 W to 50 W when irradiance varies from 200 W/m2 to 1000 W/m2 at STC temperature. At temperatures higher than STC and for the same solar irradiance, the power output of the PV module came down about 14.5% only when the operating temperature reached a value of 65 °C. However, as temperature is below STC, the power output went up of about 7.4% beyond the maximum power of the rated PV panel. The calculated power temperature coefficient was about −0.39%/ oC which is quite close to the one provided by the solar panel manufacturer.

Modifications to Accelerate the Iterative Algorithm for the Single Diode Model of PV Model

This paper discussed the solution of an equivalent circuit of solar cell, where a single diode model is presented. The nonlinear equation of this model has suggested and analyzed an iterative algorithm, which work well for this equation with a suitable initial value for the iterative. The convergence of the proposed method is discussed. It is established that the algorithm has convergence of order six. The proposed algorithm is achieved with a various values of load resistance. Equation by means of equivalent circuit of a solar cell so all the determinations is achieved using Matlab in ambient temperature. The obtained results of this new method are given and the absolute errors is demonstrated.

The Study on Micromismatch Losses of the Bifacial PV Modules Due to the Irradiance Nonuniformity on Its Backside Surface

Compared with monofacial photovoltaic (PV) modules, the output power of bifacial modules is higher since they can utilize additional sunlight of backside. Therefore, the backside irradiance distributions have a great influence on the performance of the bifacial modules. In this article, the backside irradiance distributions of the bifacial PV modules were studied according to the view factor models. Based on irradiance nonuniformity of the PV module backside and single diode model of solar cell equivalent circuit, the micromismatch losses were calculated by the IV curve superposition method. In addition, simulations and experiments of the backside irradiance nonuniformity is designed in Changzhou, China, to verify the theoretical calculation model. According to simulation and experiment result, the micromismatch losses of bifacial modules under different conditions (including grassland, cement floor, snowfield, with and without crossbeam) were analyzed. In the simulation, the micromismatch loss of bifacial PV module in PV system is less than 3%, which depends on field surrounding ground of PV modules. The losses in grassland, cement floor, snow ground is 0.3%-0.5%, 0.5%-1%, 1%-3%, respectively. Due to the shadows of PV module mounting frame, the micromismatch loss will increase by 0.5%-3.3%.

Estimation of Output Power for PV Module with Damaged Bypass Diode using MATLAB

Installed PV module in field is affected by shading caused by various field environmental factors. Bypass diodes are installed in PV module for preventing a power loss and degradation of PV module by shading. But, Bypass diode is easily damaged by surge voltage and has often initial a defect. This paper propose the electric characteristic variation and the power prediction of PV module with damaged bypass diode. Firstly, the resistance for normal bypass diode and damaged bypass diode of resistance was measured by changing the current. When the current increases, the resistance of normal bypass diode is almost constant but the resistance of damaged bypass diode increases. Next, To estimate power of PV module by damaged bypass diode, the equation for the current is derived using solar cell equivalent circuit. Finally, the derived equation was simulated by using MatLab tools, was verified by comparing experimental data.

Analysis of the Stationary and Transient Behavior of a Photovoltaic Solar Array: Modeling and Simulation

behavior of a photovoltaic solar array is investigated by performing a simulation in Simulink (MATLAB). The modeling of the system is based on the one diode model (in which the solar cell's equivalent circuit is composed by a current source, diode, series and parallel resistance). The simulation results show how the series and parallel connection of the solar cells have a direct impact under the maximum voltage and current that the array can generate, respectively. The linear dependence of the array's current with respect to the solar irradiance is also exposed. Not only its stationary performance but also its transient behavior is discussed by adding a capacitor on the model to represent the influence of the charge separation that occurs at the depletion region.

A simple but accurate procedure for solving the five-parameter model

The current–voltage characteristic of a photovoltaic module is typically evaluated by using a model based on the solar cell equivalent circuit. The complexity of the procedure applied for extracting the model parameters depends on data available in manufacture’s datasheet. Since the datasheet is not detailed enough, simplified models have to be used in many cases. This paper proposes a new procedure for extracting the parameters of the one-diode model in standard test conditions, using only the basic data listed by all manufactures in datasheet (short circuit current, open circuit voltage and maximum power point). The procedure is validated by using manufacturers’ data for six commercially crystalline silicon photovoltaic modules. Comparing the computed and measured current–voltage characteristics the determination coefficient is in the range 0.976–0.998. Thus, the proposed procedure represents a feasible tool for solving the five-parameter model applied to crystalline silicon photovoltaic modules. The procedure is described in detail, to guide potential users to derive similar models for other types of photovoltaic modules.

The Solar Cell Mathematical Model Simulation and Verification

The output characteristics of solar cell that researched as the target is analysed at different temperatures and light intensity .Combining with the equivalent circuit of solar cell, mathematical model is established .The system is simulated through MATLAB/Simulink and the data is compared with the actual one. The experimental results show that the model can well reproduce the output characteristics curve of solar cell at arbitrary condition and the error between the model and the actual output is decreased because of the series resistance. The system can satisfy the requirements of engineering design, in addition, the system can provides theoretical basis for simulation study of solar power generation system.

An Effective Single Solar Cell Equivalent Circuit Model for Two or More Solar Cells Connected in Series

We report on the development of a simplified single solar cell equivalent circuit model which describes two or more solar cells that are connected in series with the device parameters of a single effective solar cell. The model depends only on the voltage that is applied to the device, and effective device parameters can be calculated from subcell parameters. The constraints for the applicability of the effective model are discussed. The effective model is applicable if it is possible to determine its effective diode parameters-either by calculation or by extraction from data.

A new technique for extracting physical parameters of a solar cell model from the double exponential model (DECM)

In this paper, we propose and apply a new technique for extracting physicalparametersofsolar cell double exponential modelwithtwo ideality factor constants (DECM) from illuminated current–voltage (I–V) experimental characteristics. The equivalent circuit of solar cell includes two constant diodes ideality factors (n1=1, n2=2) with two saturation currents I0D and I0R, a current generator intensity Iph, a series resistor RS and a conductance GP. A set of current–voltage characteristics are generated by injecting various RS values in the characteristic equation. Using the area error rate (“%ΔArea,”) between the experimental and extracted (I–V) characteristics, the value of RS is deduced as the minimum of this error. The obtained results show a good agreement with the experimental characteristics measured on a commercial polycrystalline solar cell.

Design of photovoltaic device and DC–DC converter on a single chip using 0.18 μm standard CMOS technology

In this paper, we propose a photovoltaic power supply for a stand-alone system that provides electrical generation and voltage boost functions on a single silicon chip. This power supply consists of solar cells, an oscillator, and a bootstrap charge pump, which are all designed in a 0.18 μm standard complementary metal-oxide semiconductor technology. Two types of solar cells are embedded in the system to improve its power efficiency. One type is used for the power supply and the other type is used to provide the voltage bias. Three different solar cells structures were designed. A pn structure and an np structure are used for the power supply cells and an npn series-connected structure is used for the oscillator circuit to operate the DC---DC converter The voltage-current characteristics of the solar cell under microscopic illumination have been measured and the performance of bootstrap charge pump circuits was confirmed. We remodeled our solar cell equivalent circuit to reflect these measurement results.

Fill factor in organic solar cells

The fill factor (FF) is an important parameter that determines the power conversion efficiency of an organic solar cell. There are several factors that can significantly influence FF, and these factors interact with each other very intricately. Due to this reason, a deep understanding of FF is quite difficult. Based on the three fundamental elements in the solar cell equivalent circuit, namely series resistance, shunt resistance and diode, we reviews the research progress in understanding on FF in organic solar cells. Physics lying behind the often-observed undesirable S-shaped J-V curves is also summarized. This paper aims to give a brief and comprehensive summary on FF from a fundamental point of view.

Improved PV Module Performance under Partial Shading Conditions

In a typical series-connected photovoltaic module with three bypass diodes, not all of the energy generated by the individual cells in the module can be collected when one or more of the cells in the module are partially shaded. In this work, various photovoltaic (PV) module layouts are investigated, using both full-size solar cells and halved solar cells. The performance of these module layouts is investigated under conditions where one or more cells in the module are partially shaded. A solar cell equivalent circuit model has been implemented in the SPICE soft ware Micro-Cap to investigate several different module configurations. Module configurations investigated include a standard 72-cell module with 3 bypass diodes, one new configuration with a series of six matrices (whereby each matrix consists of two parallel strings of 12 halved cells each) with 3 bypass diodes, and another configuration with a series of 72 cells (whereby each matrix consists of two halved cells in parallel) with 3 bypass diodes. In the simulation, a shadow with zero transmittance was simulated to pass over the area of one 6-inch full-size solar cell in the corner of the module from two orthogonal directions, and the maximum power was calculated for each of the investigated module configurations. Simulation results show that the series-parallel hybrid connection of cells within a module has a significant improvement on the power output of the PV module under partial shading conditions.

A new method to characterize bifacial solar cells

We present a new method to characterize bifacial solar cells under standard test conditions (STC). The method considers the bifacial operation of the cell and provides the characteristics for simultaneous front and rear side illumination rather than providing the front and the rear side characteristics separately. The method involves measurements of front side electrical parameters (efficiency, open-circuit voltage, short-circuit current and fill factor) and rear side short-circuit current under STC. Two new parameters are introduced, namely bifacial 1.x efficiency (effective efficiency) and gain-efficiency product, which are calculated from the measured STC parameters. The former provides information related to the cell design considering the bifacial operation, whereas the latter provides the end-use benefits from the modules with bifacial cells for a particular installation. To calculate the bifacial 1.x efficiency and the gain-efficiency product, a one-diode solar cell equivalent circuit is used. Characteristic plots are shown for the newly introduced parameters as a function of rear-side illumination for various example solar cells. A sensitivity analysis is performed to understand the influence of each single-sided STC solar cell parameter on the newly introduced parameters. This sensitivity analysis shows that the fill factor and the rear-to-front current ratio are the most critical parameters for bifacial solar cells. Copyright © 2012 John Wiley & Sons, Ltd.

Exact analytical solution of a two diode circuit model for organic solar cells showing S-shape using Lambert W-functions

Organic solar cells (OSCs) often show a kink, also called S-shape, in the current–voltage (I–V) characteristics, that has been attributed to different physical phenomena such as poor quality of cathode-active layer interface or unbalance charge carrier mobilities. This non-ideal behaviour can be electrically modelled including a second diode, in reverse bias, together with an extra shunt resistance (RP2) in the traditional solar cell equivalent circuit. In this paper, we solve without approximations the transcendental equation system derived from this modified circuit. We have obtained an analytical expression for I–V curves decoupling the voltage drop in each diode using Lambert W function. This expression has been fitted to experimental data in order to obtain circuital parameters. Simulations varying saturation current of reverse diode (I02) and RP2 have been performed in order to study the dependence of S-shape with these parameters.

The influence of the measurement environment on the accuracy of the extraction of the physical parameters of solar cells

This article concerns the influence of measurement conditions on the extraction of a solar cell's equivalent circuit parameters. Influences previously not investigated are considered, thus helping to define suitable measurement strategies. The influences of measurement environments are investigated, as is the influence of the fitting algorithm chosen. It is shown that the number of measurement points for the current-voltage characteristic can have an important effect on the accuracy of the parameters extracted. The stability of the system is of minor importance, as long as the variations in the measurement conditions are monitored. We also show that the Marquardt-Levenberg algorithm using a least squares error criterion and a hybrid algorithm employing an area criterion outperform other choices of fitting algorithm.