Six-parameter electrical model for photovoltaic cell/module with compound parabolic concentrator

One problem with concentrating photovoltaic systems is the increase in operating photovoltaic module temperature which results in power output reduction. Indium Tin Oxide (ITO) coated glasses exhibit both high transmittance in the visible region and high reflectance in the infrared region of the solar spectrum. Such materials can be used as selective windows in photovoltaic modules operating under concentrating system enabling passive cooling. In this paper, a Heat Reflector Window (HRW) consisting of a glass coated with 180 nm layer of ITO was experimentally tested. The ITO coated glass had a transmittance of about 85% in the visible region and over 80% reflectance in the infrared region of the solar spectrum and was placed at the exit aperture of a Compound Parabolic Concentrator (CPC). Results indicate that the temperature of a photovoltaic module under CPC with the HRW was reduced by about 50% as compared to a similar photovoltaic module with CPC but without the HRW. However, due to presence of the HRW at the exit aperture of the CPC, the photovoltaic module with the CPC and HRW received less solar irradiance compared to a similar photovoltaic module with the CPC but without HRW.

The use of concentrating systems has been proposed as a way to reduce the cost of electrical energy from photovoltaic (PV) module. Since 1970s, different solar collector designs have been used to increase energy flux on the PV module. This study aims at providing a comprehensive review of development in the application of compound parabolic concentrators (CPCs) to solar photovoltaic conversion for the past five decades. By narrowing down the application of CPCs to electrical energy only gives a reader an opportunity to clearly understand the detail development stages, challenges, and research opportunities for further improvement. From this review, it has been found that during 1970s, all studies on the application of CPCs to solar photovoltaic conversion were mainly focused on establishing technical feasibility and cost effectiveness. Thereafter (1981-May 2018), extensive studies were carried out to resolve challenges that were observed during the establishment stage. However, it has been found that even though the power output of the PV modules with the CPC was always higher than similar modules without the CPC, the values were less than the expected (theoretical) results. This was due to optical losses, series resistance losses, non-uniform illumination effect, and high operating cell temperature effect. In addition, high cost of the PV-CPC systems and low concentration ratio of the CPCs were also the main concerns of various researchers.

Solar cell/module modeling involves the formulation of the non-linear current versus voltage (I-V) curve. Determination of parameters plays an important role in solar cell/module modeling. This paper presents an application of the improved PSO search method and Particle Swarm Optimization technique for identifying the unknown parameters of solar cell and photovoltaic module models, namely, the series resistance, shunt resistance, generated photocurrent, saturation current, and ideality factor that govern the current-voltage relationship of a solar cell/module. For the confirmation of accuracy of the proposed method, a measurement data of 57 mm diameter commercial (R.T.C. France) silicon solar cell and a module consisting of 36 polycrystalline silicon cells (Photowatt-PWP 201) has been selected and the best optimal value of each parameter has been obtained using Improved PSO. Comparative study among different parameter estimation techniques is presented to demonstrate to verify the accurateness and the effectiveness of the proposed approach.

Performance investigation of truncated low concentrating photovoltaic-thermal systems with V-trough, compound hyperbolic and compound parabolic concentrators

Predicting the performance of photovoltaic (PV) systems in industrial applications has become increasingly important due to the complex and non-linear behavior of PV modules. Accurate performance prediction is essential for optimizing energy production and ensuring system reliability. However, a significant challenge arises from the lack of critical information in manufacturer datasheets, which often do not include all the necessary details for precise PV module modeling. This limitation can hinder accurate analysis and system performance evaluation. Optimization methods are recommended to accurately determine the electrical and physical characteristics of PV cells and modules to address this issue. These methods enable detailed and precise analysis of current-voltage (I-V) and power-voltage (P-V) characteristics across various PV models, improving the overall modeling accuracy. Among these methods, the Rao-1 optimization technique has been selected and evaluated in this paper to solve this issue. It is specifically used to extract the unknown parameters of photovoltaic models, including the photo-generated current (Iph), diode ideality factor (n), series resistance (Rs), reverse saturation current (I0), and shunt resistance (Rsh). The effectiveness of the Rao-1 optimization method has been demonstrated through its successful application in estimating PV parameters across a wide range of datasets, ensuring its reliability and adaptability for various industrial scenarios.

This work introduces a electric-thermal model for a photovoltaic (PV) cell which combines electrical and thermal parameters, and also incorporates dynamic characteristics and accurate modeling in the reverse-bias region. Incoming irradiance and ambient temperature are used to calculate the PV cell temperature based on a five-layer thermal model. The cell temperature in the electrical model is updated according to the thermal model to accurately adjust the PV cell output electrical characteristics. To test and validate the electrical and thermal characteristics of the PV cell, a custom setup was built that allows temperature measurement at the PV cell and glass surfaces. Performance of the electric-thermal model in both forward- and reverse-bias region is verified using experimental data in realistic scenarios. This PV model can be scaled up and used to simulate PV systems in a wide variety of applications, extreme environmental conditions, and fault conditions.

The computer program called Solar_PVHFC has been modified to model a compound parabolic concentrator (CPC) that uses photovoltaic cells to produce electrical energy. This program was used to study the effects of concentration ratio, truncation height ratio, and photovoltaic cell efficiency on electrical power output and relative levelized cost of energy (LCE) of a fixed CPC photovoltaic device. Comparisons are made to fixed, conventional flat photovoltaic panels. This study indicates that CPCs can reduce the levelized cost of electrical energy produced by high efficiency, high cost photovoltaic cells, but provides no advantages for lower efficiency, lower price photovoltaic cells.

A C++-based automatic executable program is implemented and provided in this article to integrate the current minus the short-circuit current, using the 3/8 integration rule, to compute the Co-Content function. The shunt ( Rsh ) and series resistance ( Rs ), photo ( Iph ) and saturation current ( Isat ), and ideality factor ( n ) (within the one-diode solar cell model) are then automatically calculated by the program, together with their standard deviations. When it is applied to simulated current voltage ( IV ) curves, the five solar cell parameters are extracted with less than 1% error, using only 26 points and in less than 1 s, in the case of noiseless IV curves, while in the case of 0.1% noise of the maximum current, less than 1% error is achieved with 51 points, and also in less than 1 s. The program is applied to measured IV curves in a commercial solar cell, and compared with the usual trapezoidal integration method and another method. All the solar cell parameters are reasonably extracted in under one second, whereas other techniques require at least 7 min.

Hybrid concentrated photovoltaic and thermal power conversion at different spectral bands

This work presents a Simulink-based model of a photovoltaic (PV) system using a single-diode and two-diode model of solar cell. A comparison between the two-diode and single-diode model of PV cell has been illustrated. In addition, the output of series-parallel connection of PV cells has been examined. In the model, series and shunt resistances are calculated by an efficient iteration method based on open-circuit voltage, short-circuit current and irradiance values. The PV module implemented in Simulink/MATLAB considers five parameters. The parameters are series and shunt resistance, reverse saturation current, photocurrent and ideality factor. Approximate parameters are obtained from the manufacturers datasheets. The model includes light intensity and ambient temperature as input. Power, cell temperature and voltage as well as any measurements of interests are the outputs. For the grid connection of solar cell, inverter, filter and a step-up transformer is utilized. The performance of the model is found satisfactory.

Effect of Series and Shunt Resistance on Organic-Inorganic Hybrid Solar Cells Performance

In this work, we present three methods to extract model physical parameters of a photovoltaic solar module modelled by a single-diode electronic circuit. The model physical parameters we are looking for are photocurrent Iph , saturation current Is , ideality factor η, series resistance Rs and shunt conductance Gp . The first method is based on exact solution of module characteristic equation, the second one uses exact expression of dynamic conductance and the third one makes use of exact expression of the integral of translated current-voltage characteristics (I-Isc ). In all these extraction methods, we achieve numerical fitting of experimental data of output current, differential conductance and area under translated characteristics with suitable analytical expressions to get model physical parameters at standard test conditions (STC). Then, we assume these values as initial conditions and derive exact analytical expressions reporting effects of module temperature and incident solar irradiance on photocurrent, saturation current and ideality factor using temperature coefficients provided as well as irradiance coefficients extracted from module manufacturer datasheet. We examine new analytical expressions of model physical parameters in the case of Shell SQ80 photovoltaic solar module at arbitrary operating conditions of module temperature and solar irradiance. We evidence good agreement between experimental characteristics and forecasted analytical characteristics generated by new analytical expressions.

An accurate model for photovoltaic (PV) modules to determine electrical characteristics and thermodynamic performance parameters

There is a need for an accurate method for modeling the Photovoltaic (PV) cell, because the modeling of PV cell is based on manufacturer datasheet. The manufacturer datasheet is recorded under standard test condition (STC) and under laboratory conditions, especially the PV cell temperature, where the temperature used in modeling is ambient temperature, but in the real operation of a PV cell, there are huge differences between ambient temperature and PV cell temperature. Therefore, in this paper a novel approach is used for modeling a PV array by the use of back of panel temperature and real life recorded data (outdoor data). The developed model gives a real life operation condition according to the simulation results, which is compared with validation data (real life data).

The increasing demand for electrical energy has made it inevitable to bring forth an environment-friendly energy resource which has to be robust as well as economic. Solar energy fulfils these criteria significantly, and to cultivate such energy, a reliable photovoltaic (PV) model is required. But most of the typical PV system undergoes a low energy conversion ratio because of improper choice of PV parameters. To build a proficient PV model, the estimation of precise and accurate parameters is mandatory. This paper portrays the Sine Cosine Algorithm (SCA) for the estimation of photovoltaic (PV) module parameters. Unknown parameters of the PV model of a single diode PV module are estimated under the standard test condition (STC). PV parameter estimation using SCA has shown a significant minimum value of the fitness function hence maximizing the convergence. A comparative study has been done between SCA and other existing popular techniques named as the nonlinear least square (NLS) method and the modified Newton–Raphson (N-R) method. From the power–voltage (P-V) and current–voltage (I-V) characteristics, it’s found that the SCA model matches more accurately with the datasheet values.KeywordsRenewable energyPhotovoltaicSingle diode modelSine cosine algorithmParameter estimation