This paper presents a method for calculating the light generated current, the series resistance, shun
resistance and the two components of the reverse saturation current usually encountered in the double
diode representation of the solar cell from the experimental values of the current-voltage characteristics
of the cell using genetic algorithm. The theory is able to regenerate the above mentioned parameters to
very good accuracy when applied to cell data that was generated from pre-defined parameters. The
method is applied to various types of space quality solar cells and sub cells. All parameters except the
light generated current are seen to be nearly the same in the case of a cell whose characteristics under
illumination and in dark were analyzed. The light generated current is nearly equal to the short- circuit
current in all cases. The parameters obtained by this method and another method are nearly equal
wherever applicable. The parameters are also shown to represent the current-voltage characteristics
well.
Reconstruction of electrical impedance tomography images based on the expecta...ISA Interchange
Electrical impedance tomography (EIT) calculates the internal conductivity distribution within a body using electrical contact measurements. The image reconstruction for EIT is an inverse problem, which is both non-linear and ill-posed. The traditional regularization method cannot avoid introducing negative values in the solution. The negativity of the solution produces artifacts in reconstructed images in presence of noise. A statistical method, namely, the expectation maximization (EM) method, is used to solve the inverse problem for EIT in this paper. The mathematical model of EIT is transformed to the non-negatively constrained likelihood minimization problem. The solution is obtained by the gradient projection-reduced Newton (GPRN) iteration method. This paper also discusses the strategies of choosing parameters. Simulation and experimental results indicate that the reconstructed images with higher quality can be obtained by the EM method, compared with the traditional Tikhonov and conjugate gradient (CG) methods, even with non-negative processing.
AN IMPROVED METHOD FOR IDENTIFYING WELL-TEST INTERPRETATION MODEL BASED ON AG...IAEME Publication
This paper presents an approach based on applying an aggregated predictor formed by multiple versions of a multilayer neural network with a back-propagation optimization algorithm for helping the engineer to get a list of the most appropriate well-test interpretation models for a given set of pressure/ production data. The proposed method consists of three stages: (1) data decorrelation through principal component analysis to reduce the covariance between the variables and the dimension of the input layer in the artificial neural network, (2) bootstrap replicates of the learning set where the data is repeatedly sampled with a random split of the data into train sets and using these as new learning sets, and (3) automatic reservoir model identification through aggregated predictor formed by a plurality vote when predicting a new class. This method is described in detail to ensure successful replication of results. The required training and test dataset were generated by using analytical solution models. In our case, there were used 600 samples: 300 for training, 100 for cross-validation, and 200 for testing. Different network structures were tested during this study to arrive at optimum network design. We notice that the single net methodology always brings about confusion in selecting the correct model even though the training results for the constructed networks are close to 1. We notice also that the principal component analysis is an effective strategy in reducing the number of input features, simplifying the network structure, and lowering the training time of the ANN. The results obtained show that the proposed model provides better performance when predicting new data with a coefficient of correlation approximately equal to 95% Compared to a previous approach 80%, the combination of the PCA and ANN is more stable and determine the more accurate results with lesser computational complexity than was feasible previously. Clearly, the aggregated predictor is more stable and shows less bad classes compared to the previous approach.
This paper presented the study, development and implementation of the maximum power point of a photovoltaic energy generator adapted by elevator converter and controlled by a maximum power point command. In order to improve photovoltaic system performance and to force the photovoltaic generator to operate at its maximum power point, the idea of the context of this paper deals with the exploitation of the technique of the artificial intelligence mechanism (neural network) certainly based on the three parts of the photovoltaic system (photovoltaic module inputs (temperature and solar radiation), photovoltaic module and control (MPPT)) that have been adopted within a simulation time of 24 hours. In addition, to reach the optimal operating point regardless of variations in climatic conditions, the use of a neuron network based disturbance and observation algorithm (P&O) is put into service of the system given its reliability, its simplicity and view that at any time it can follow the desired maximum power. The entire system is implemented in the Matlab / Simulink environment where simulation results obtained are very promising and have shown the effectiveness and speed of neural technology that still require a learning base so to improve the performance of photovoltaic systems and exploit them in energy production, as well as this technique has proved that these results are much better in terms (of its very great precision and speed of computation) than those of the controller based on the conventional MPPT method P&O.
IMPLEMENTATION OF A REAL TIME MONITORING SYSTEM FOR A PHOTOVOLTAIC GENERATION...adeij1
Generally PV generators are considered reliable compared to other systems, but like all processes, a PV system can be exposed to several failures causing the PV system to malfunction. Several studies have found that the reliability of PV systems is highly dependent on the equipment used for the construction of PV panels, temperature, humidity and solar radiation. A PV system can have several defects, be it defects of construction types, or material and electrical defects caused by climatic conditions. As such, we can cite the fault most commonly encountered in a PV generator which is the partial shading defect.
Mathematical Modelling and Computer Simulation Assist in Designing Non-tradit...IJECEIAES
The article deals with the application of the method for mathematical modeling and simulation at solving some issues in the area of electrostatic technology. It focuses on the processes in electrostatic separation and precipitation. Computer simulation is highly required for equipment design and for their diagnostics in critical operating states using theoretical calculations and experimental data evaluation. The presented computer models may be applied both by project and design engineers using the most advanced computer-aided design of electrostatic technologies.
Active vibration control of smart piezo cantilever beam using pid controllereSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Reconstruction of electrical impedance tomography images based on the expecta...ISA Interchange
Electrical impedance tomography (EIT) calculates the internal conductivity distribution within a body using electrical contact measurements. The image reconstruction for EIT is an inverse problem, which is both non-linear and ill-posed. The traditional regularization method cannot avoid introducing negative values in the solution. The negativity of the solution produces artifacts in reconstructed images in presence of noise. A statistical method, namely, the expectation maximization (EM) method, is used to solve the inverse problem for EIT in this paper. The mathematical model of EIT is transformed to the non-negatively constrained likelihood minimization problem. The solution is obtained by the gradient projection-reduced Newton (GPRN) iteration method. This paper also discusses the strategies of choosing parameters. Simulation and experimental results indicate that the reconstructed images with higher quality can be obtained by the EM method, compared with the traditional Tikhonov and conjugate gradient (CG) methods, even with non-negative processing.
AN IMPROVED METHOD FOR IDENTIFYING WELL-TEST INTERPRETATION MODEL BASED ON AG...IAEME Publication
This paper presents an approach based on applying an aggregated predictor formed by multiple versions of a multilayer neural network with a back-propagation optimization algorithm for helping the engineer to get a list of the most appropriate well-test interpretation models for a given set of pressure/ production data. The proposed method consists of three stages: (1) data decorrelation through principal component analysis to reduce the covariance between the variables and the dimension of the input layer in the artificial neural network, (2) bootstrap replicates of the learning set where the data is repeatedly sampled with a random split of the data into train sets and using these as new learning sets, and (3) automatic reservoir model identification through aggregated predictor formed by a plurality vote when predicting a new class. This method is described in detail to ensure successful replication of results. The required training and test dataset were generated by using analytical solution models. In our case, there were used 600 samples: 300 for training, 100 for cross-validation, and 200 for testing. Different network structures were tested during this study to arrive at optimum network design. We notice that the single net methodology always brings about confusion in selecting the correct model even though the training results for the constructed networks are close to 1. We notice also that the principal component analysis is an effective strategy in reducing the number of input features, simplifying the network structure, and lowering the training time of the ANN. The results obtained show that the proposed model provides better performance when predicting new data with a coefficient of correlation approximately equal to 95% Compared to a previous approach 80%, the combination of the PCA and ANN is more stable and determine the more accurate results with lesser computational complexity than was feasible previously. Clearly, the aggregated predictor is more stable and shows less bad classes compared to the previous approach.
This paper presented the study, development and implementation of the maximum power point of a photovoltaic energy generator adapted by elevator converter and controlled by a maximum power point command. In order to improve photovoltaic system performance and to force the photovoltaic generator to operate at its maximum power point, the idea of the context of this paper deals with the exploitation of the technique of the artificial intelligence mechanism (neural network) certainly based on the three parts of the photovoltaic system (photovoltaic module inputs (temperature and solar radiation), photovoltaic module and control (MPPT)) that have been adopted within a simulation time of 24 hours. In addition, to reach the optimal operating point regardless of variations in climatic conditions, the use of a neuron network based disturbance and observation algorithm (P&O) is put into service of the system given its reliability, its simplicity and view that at any time it can follow the desired maximum power. The entire system is implemented in the Matlab / Simulink environment where simulation results obtained are very promising and have shown the effectiveness and speed of neural technology that still require a learning base so to improve the performance of photovoltaic systems and exploit them in energy production, as well as this technique has proved that these results are much better in terms (of its very great precision and speed of computation) than those of the controller based on the conventional MPPT method P&O.
IMPLEMENTATION OF A REAL TIME MONITORING SYSTEM FOR A PHOTOVOLTAIC GENERATION...adeij1
Generally PV generators are considered reliable compared to other systems, but like all processes, a PV system can be exposed to several failures causing the PV system to malfunction. Several studies have found that the reliability of PV systems is highly dependent on the equipment used for the construction of PV panels, temperature, humidity and solar radiation. A PV system can have several defects, be it defects of construction types, or material and electrical defects caused by climatic conditions. As such, we can cite the fault most commonly encountered in a PV generator which is the partial shading defect.
Mathematical Modelling and Computer Simulation Assist in Designing Non-tradit...IJECEIAES
The article deals with the application of the method for mathematical modeling and simulation at solving some issues in the area of electrostatic technology. It focuses on the processes in electrostatic separation and precipitation. Computer simulation is highly required for equipment design and for their diagnostics in critical operating states using theoretical calculations and experimental data evaluation. The presented computer models may be applied both by project and design engineers using the most advanced computer-aided design of electrostatic technologies.
Active vibration control of smart piezo cantilever beam using pid controllereSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Active vibration control of smart piezo cantilever beam using pid controllereSAT Journals
Abstract In this paper the modelling and Design of a Beam on which two Piezoelectric Ceramic Lead Zirconate Titanate ( PZT) patches are bonded on the top and bottom surface as Sensor/Actuator collocated pair is presented. The work considers the Active Vibration Control (AVC) using Proportional Integral Derivative (PID) Controller. The beam is assumed as Euler-Bernoulli beam. The two PZT patches are also treated as Euler-Bernoulli beam elements. The contribution of mass and stiffness of two PZT patches in the design of entire structure are also considered. The beam is modelled using three Finite Elements. The patches can be bonded near the fixed end, at middle or near the free end of the beam as collocated pair. The design uses first two dominant vibratory modes. The effect of PZT sensor/actuator pair is investigated at different locations of beam in vibration control. It can be concluded from the work that best result is obtained when the PZT patches are bonded near the fixed end. Keywords: Smart Beam, Active Vibration control, Piezoelectric, PID Controller, Finite Element
LabVIEW Interface for Controlling a Test Bench for Photovoltaic Modules and E...IAES-IJPEDS
Numerical simulation using mathematical models that take into account
physical phenomena governing the operation of solar cells is a powerful tool
to predict the energy production of photovoltaic modules prior to installation
in a given site. These models require some parameters that manufacturers do
not generally give. In addition, the availability of a tool for the control and
the monitoring of performances of PV modules is of great importance for
researchers, manufacturers and distributors of PV solutions. In this paper, a
test and characterization protocol of PV modules is presented. It consists of
an outdoor computer controlled test bench using a LabVIEW graphical
interface. In addition to the measuring of the IV characteristics, it provides
all the parameters of PV modules with the possibility to display and print a
detailed report for each test. After the presentation of the test bench and the
developed graphical interface, the obtained results based on an experimental
example are presented.
Hybrid neural networks in cyber physical system interface control systemsjournalBEEI
The calculation and results of simulation of the magnetic control system for the spacecraft momentum are presented in the paper. The simulation includes an assessment of the reliability of calculating the Earth's magnetic field parameters, as well as an assessment of the quality of object stabilization by resetting the total momentum with the aid of the system under review. The outcome of a comparative analysis of resource efficiency and energy efficiency are demonstrated in the implementation of the proposed hardware models of controllers on FPGA. The strengths and weaknesses of the programming models are shown. The developed models will allow to be modified and perform more complex operations in the future.
Short Term Electrical Load Forecasting by Artificial Neural NetworkIJERA Editor
This paper presents an application of artificial neural networks for short-term times series electrical load
forecasting. An adaptive learning algorithm is derived from system stability to ensure the convergence of
training process. Historical data of hourly power load as well as hourly wind power generation are sourced from
European Open Power System Platform. The simulation demonstrates that errors steadily decrease in training
with the adaptive learning factor starting at different initial value and errors behave volatile with constant
learning factors with different values
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
This presentation was given at the 2009 SPIE conference in San Diego, CA.
Actuators employing ferroelectric or ferromagnetic compounds are solid-state, efficient, and compact making them well-suited for aerospace, aeronautic, industrial and military applications. However, they also exhibit frequency, stress and thermally-dependent hysteresis and constitutive nonlinearities which must be incorpo-rated in models for accurate device characterization and control design. A critical step in the use of these models is the estimation or re-estimation of parameters in a manner that is both efficient and robust. In this presentation, we discuss techniques to estimate densities in the homogenized energy model based on Galerkin expansions using physically motivated basis functions. The yields highly tractable optimization algorithms in which initial parameter estimates can be obtained from measured properties of the data. The efficiency and accuracy of the models and estimation algorithms are validated with experimental data.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
A Comparative Analysis of Intelligent Techniques to obtain MPPT by Metaheuris...IJMTST Journal
Main objective of this paper is to develop an intelligent and efficient Maximum Power Point Tracking (MPPT) technique. Most recently introduced of intelligent based algorithm Cuckoo search algorithm has been used in this study to develop a novel technique to track the Maximum Power Point (MPP) of a solar cell module. The performances of this algorithm has been compared with other evolutionary soft computing techniques like ABC, FA and PSO. Simulations were done in MATLAB/SIMULINK environment and simulation results show that proposed approach can obtain MPP to a good precision under different solar irradiance and environmental temperatures.
Improving the efficiency of photovoltaic cells embedded in floating buoysIJECEIAES
Solar cells are used to power floating buoys, which is one of their applications. Floating buoys are devices that are placed on the sea and ocean surfaces to provide various information to the floats. Because these cells are subjected to varying environmental conditions, modeling and simulating photovoltaic cells enables us to install cells with higher efficiency and performance in them. The parameters of the single diode model are examined in this article so that the
I-V, P-V diagrams, and characteristics of the cadmium telluride (CdTe) photovoltaic cell designed with three layers (CdTe, CdS, and SnOx) can be extracted using a solar cell capacitance simulator (SCAPS) software, and we obtain the parameters of the single diode model using the ant colony optimization (ACO) algorithm. In this paper, the objective function is root mean square error (RMSE), and the best value obtained after 30 runs is 5.2217×10-5 in 2.46 seconds per iteration, indicating a good agreement between the simulated model and the real model and outperforms many other algorithms that have been developed thus far. The above optimization with 200 iterations, a population of 30, and 84 points was completed on a server with 32 gigabytes of random-access memory (RAM) and 30 processing cores.
Comparative study of one and two diode model of solar photovoltaic celleSAT Journals
Abstract Modeling of solar cell is a very difficult task. This is because of the non linear behavior of the cell. Different types of modeling for solar cells are available in the literature. The theme of the modeling is based on the solar radiation and temperature of the system and environment. Determination of cell parameters like Iph, Is, Rs ,Rsh and ideality factor generally affects the performance of the solar cell. This paper will basically describe about the one diode model of the solar cell. The initial parameter are evaluated by generating some random number through a computer program and from the manufacturer data sheet provided by the manufacturer. The result of the simulation will describe about the performance of two types of model. Keywords: Solar PV, One diode model, Two diode model
Study and Simulation of Inccond Based Maximum Power Point Tracking (MPPT) Alg...paperpublications3
Abstract: The entire world is facing a challenge to overcome the hurdle of energy crisis. It is fairly evident that a need exist for developing alternative energy sources. Amongst all the available renewable energy sources, solar energy appears to be a viable option as it is easily and widely available. If used in a proper way, it has a capacity to fulfill numerous energy needs of the world. Hence there is great scope of work in field of solar photovoltaic aiming at improved and efficient performances. Solar PV modules convert solar energy into electrical form but are having high non-linear current-voltage relationship which implies that they can operate at only one single point for maximum power. So extraction of maximum power in itself becomes a challenge under varying set of conditions of irradiation and temperature. A step by step approach is followed to analyze and address the problem with high frequency switching DC-DC converters that act as an interface between the module and the load and adjust the switching duty ratio so as to match the load line with that of Maximum Power Point load line. Further there exist various control algorithms to modify duty ratio. Their study is done and one such technique Incremental Conductance (IncCond) is used to process current and voltage of PV array to get the duty ratio. The results are obtained for changing radiation as well. In the present study, a review of Hill Climbing MPPT techniques, has been carried out with detailed flowcharts of algorithms and includes latest research papers published on MPPT techniques.
Comparative analysis of evolutionary-based maximum power point tracking for ...IJECEIAES
The characteristics of the photovoltaic module are affected by the level of solar irradiation and the ambient temperature. These characteristics are depicted in a V-P curve. In the V-P curve, a line is drawn that shows the response of changes in output power to the level of solar irradiation and the response to changes in voltage to ambient temperature. Under partial shading conditions, photovoltaic (PV) modules experience non-uniform irradiation. This causes the V-P curve to have more than one maximum power point (MPP). The MPP with the highest value is called the global MPP, while the other MPP is the local MPP. The conventional MPP tracking technique cannot overcome this partial shading condition because it will be trapped in the local MPP. This article discusses the MPP tracking technique using an evolutionary algorithm (EA). The EAs analyzed in this article are genetic algorithm (GA), firefly algorithm (FA), and fruit fly optimization (FFO). The performance of MPP tracking is shown by comparing the value of the output power, accuracy, time, and tracking effectiveness. The performance analysis for the partial shading case was carried out on various populations and generations.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
A study on modelling and simulation of photovoltaic cellseSAT Journals
Abstract This Paper presents a detailed study on the types of modelling of the PV Panel for simulation studies. The main concern of this study is to analyze the results and compare them under standard test conditions. PV systems are generally integrated with specific control algorithms in order to extract the maximum possible power. Hence it is highly imperative that the Maximum Power Point (MPP) is achieved effectively and thus we need to design a model from which the MPPT algorithm can be realized in an efficient way. Also other parameters should be taken into account for finding the best model for the use in simulation. It is very important to choose the appropriate model based on the application. The models used for study in this paper include the single diode model, two diode model and Simscape modelling. MATLAB/Simulink presents a powerful tool to study such systems. The work tests the accuracy of the models under different temperature and irradiance conditions. The two diode model is known to have better accuracy at low irradiance levels which allows for a more accurate prediction of PV system performance. Simscape, part of Simulink environment, has a solar cell block that makes building a PV model straightforward and much easier programming with full demonstration to all system details. On the basis of the study, the best model that can be used for simulation purposes can be selected. It is envisaged that the work can be very useful for professionals who require simple and accurate PV simulators for their design. All the systems here are modeled and simulated in MATLAB/Simulink environment. Keywords: PV cell, STC, MATLAB Simulink, Ideality Factor
Active vibration control of smart piezo cantilever beam using pid controllereSAT Journals
Abstract In this paper the modelling and Design of a Beam on which two Piezoelectric Ceramic Lead Zirconate Titanate ( PZT) patches are bonded on the top and bottom surface as Sensor/Actuator collocated pair is presented. The work considers the Active Vibration Control (AVC) using Proportional Integral Derivative (PID) Controller. The beam is assumed as Euler-Bernoulli beam. The two PZT patches are also treated as Euler-Bernoulli beam elements. The contribution of mass and stiffness of two PZT patches in the design of entire structure are also considered. The beam is modelled using three Finite Elements. The patches can be bonded near the fixed end, at middle or near the free end of the beam as collocated pair. The design uses first two dominant vibratory modes. The effect of PZT sensor/actuator pair is investigated at different locations of beam in vibration control. It can be concluded from the work that best result is obtained when the PZT patches are bonded near the fixed end. Keywords: Smart Beam, Active Vibration control, Piezoelectric, PID Controller, Finite Element
LabVIEW Interface for Controlling a Test Bench for Photovoltaic Modules and E...IAES-IJPEDS
Numerical simulation using mathematical models that take into account
physical phenomena governing the operation of solar cells is a powerful tool
to predict the energy production of photovoltaic modules prior to installation
in a given site. These models require some parameters that manufacturers do
not generally give. In addition, the availability of a tool for the control and
the monitoring of performances of PV modules is of great importance for
researchers, manufacturers and distributors of PV solutions. In this paper, a
test and characterization protocol of PV modules is presented. It consists of
an outdoor computer controlled test bench using a LabVIEW graphical
interface. In addition to the measuring of the IV characteristics, it provides
all the parameters of PV modules with the possibility to display and print a
detailed report for each test. After the presentation of the test bench and the
developed graphical interface, the obtained results based on an experimental
example are presented.
Hybrid neural networks in cyber physical system interface control systemsjournalBEEI
The calculation and results of simulation of the magnetic control system for the spacecraft momentum are presented in the paper. The simulation includes an assessment of the reliability of calculating the Earth's magnetic field parameters, as well as an assessment of the quality of object stabilization by resetting the total momentum with the aid of the system under review. The outcome of a comparative analysis of resource efficiency and energy efficiency are demonstrated in the implementation of the proposed hardware models of controllers on FPGA. The strengths and weaknesses of the programming models are shown. The developed models will allow to be modified and perform more complex operations in the future.
Short Term Electrical Load Forecasting by Artificial Neural NetworkIJERA Editor
This paper presents an application of artificial neural networks for short-term times series electrical load
forecasting. An adaptive learning algorithm is derived from system stability to ensure the convergence of
training process. Historical data of hourly power load as well as hourly wind power generation are sourced from
European Open Power System Platform. The simulation demonstrates that errors steadily decrease in training
with the adaptive learning factor starting at different initial value and errors behave volatile with constant
learning factors with different values
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
This presentation was given at the 2009 SPIE conference in San Diego, CA.
Actuators employing ferroelectric or ferromagnetic compounds are solid-state, efficient, and compact making them well-suited for aerospace, aeronautic, industrial and military applications. However, they also exhibit frequency, stress and thermally-dependent hysteresis and constitutive nonlinearities which must be incorpo-rated in models for accurate device characterization and control design. A critical step in the use of these models is the estimation or re-estimation of parameters in a manner that is both efficient and robust. In this presentation, we discuss techniques to estimate densities in the homogenized energy model based on Galerkin expansions using physically motivated basis functions. The yields highly tractable optimization algorithms in which initial parameter estimates can be obtained from measured properties of the data. The efficiency and accuracy of the models and estimation algorithms are validated with experimental data.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
A Comparative Analysis of Intelligent Techniques to obtain MPPT by Metaheuris...IJMTST Journal
Main objective of this paper is to develop an intelligent and efficient Maximum Power Point Tracking (MPPT) technique. Most recently introduced of intelligent based algorithm Cuckoo search algorithm has been used in this study to develop a novel technique to track the Maximum Power Point (MPP) of a solar cell module. The performances of this algorithm has been compared with other evolutionary soft computing techniques like ABC, FA and PSO. Simulations were done in MATLAB/SIMULINK environment and simulation results show that proposed approach can obtain MPP to a good precision under different solar irradiance and environmental temperatures.
Improving the efficiency of photovoltaic cells embedded in floating buoysIJECEIAES
Solar cells are used to power floating buoys, which is one of their applications. Floating buoys are devices that are placed on the sea and ocean surfaces to provide various information to the floats. Because these cells are subjected to varying environmental conditions, modeling and simulating photovoltaic cells enables us to install cells with higher efficiency and performance in them. The parameters of the single diode model are examined in this article so that the
I-V, P-V diagrams, and characteristics of the cadmium telluride (CdTe) photovoltaic cell designed with three layers (CdTe, CdS, and SnOx) can be extracted using a solar cell capacitance simulator (SCAPS) software, and we obtain the parameters of the single diode model using the ant colony optimization (ACO) algorithm. In this paper, the objective function is root mean square error (RMSE), and the best value obtained after 30 runs is 5.2217×10-5 in 2.46 seconds per iteration, indicating a good agreement between the simulated model and the real model and outperforms many other algorithms that have been developed thus far. The above optimization with 200 iterations, a population of 30, and 84 points was completed on a server with 32 gigabytes of random-access memory (RAM) and 30 processing cores.
Comparative study of one and two diode model of solar photovoltaic celleSAT Journals
Abstract Modeling of solar cell is a very difficult task. This is because of the non linear behavior of the cell. Different types of modeling for solar cells are available in the literature. The theme of the modeling is based on the solar radiation and temperature of the system and environment. Determination of cell parameters like Iph, Is, Rs ,Rsh and ideality factor generally affects the performance of the solar cell. This paper will basically describe about the one diode model of the solar cell. The initial parameter are evaluated by generating some random number through a computer program and from the manufacturer data sheet provided by the manufacturer. The result of the simulation will describe about the performance of two types of model. Keywords: Solar PV, One diode model, Two diode model
Study and Simulation of Inccond Based Maximum Power Point Tracking (MPPT) Alg...paperpublications3
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The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
A study on modelling and simulation of photovoltaic cellseSAT Journals
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software Scilab to obtain the characteristics (I-V), then we will study the influence of every parameter on
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ESTIMATION OF THE PARAMETERS OF SOLAR CELLS FROM CURRENT-VOLTAGE CHARACTERISTICS USING GENETIC ALGORITHM
1. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
DOI :10.5121/ijscai.2016.5103 25
ESTIMATION OF THE PARAMETERS OF SOLAR CELLS
FROM CURRENT-VOLTAGE CHARACTERISTICS
USING GENETIC ALGORITHM
Suresh E. Puthanveettil1
, Mengu Cho2
and Amrita Suresh3
1
Solar Panel Division, ISRO Satellite Centre, Bangalore 560017, India.
2
Laboratory of Spacecraft Environment Interaction Engineering, Kyushu Institute of
Technology, Kitakyushu, Japan, 804-8550
3
Birla Institute of Technology and Science Pilani- K K Birla Campus, Zuari Nagar,
Goa,India
ABSTRACT
This paper presents a method for calculating the light generated current, the series resistance, shun
resistance and the two components of the reverse saturation current usually encountered in the double
diode representation of the solar cell from the experimental values of the current-voltage characteristics
of the cell using genetic algorithm. The theory is able to regenerate the above mentioned parameters to
very good accuracy when applied to cell data that was generated from pre-defined parameters. The
method is applied to various types of space quality solar cells and sub cells. All parameters except the
light generated current are seen to be nearly the same in the case of a cell whose characteristics under
illumination and in dark were analyzed. The light generated current is nearly equal to the short- circuit
current in all cases. The parameters obtained by this method and another method are nearly equal
wherever applicable. The parameters are also shown to represent the current-voltage characteristics
well.
KEYWORDS
Solar cell, current-voltage characteristics, reverse saturation current, series resistance, shunt resistance,
particle radiation, genetic algorithm
1. INTRODUCTION
It is important to have the full characteristics of the solar cells and thus the solar array because
of several reasons. Space solar arrays are optimized for end of life conditions (EOL). Since
space systems require high reliability, the margins used are usually high and thus even at the
end of life the solar array does not operate at maximum power point. The space array
continuously undergoes irradiation by charged particles in geosynchronous orbit, low earth orbit
or medium earth orbit due to trapped protons and electrons. Solar flare protons affect even the
satellites that are situated away from the earth. Since the current from the array depends on
where the array operates at each point in its life time, it is necessary to have a proper estimate of
the full characteristics of the solar array. Sometimes, certain off-optimality for small periods is
allowed in the design of the solar array so that it operates at points between the maximum power
point and the open-circuit voltage. This is another reason why the
2. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
26
knowledge of the full I-V characteristics of the cell is necessary for optimum design and analysis
of the performance. Full I-V characteristics of solar cells are obtained from limited data by several
means. Usually, the solar cell parameters like diffusion and recombination currents, light generated
current, series resistance and shunt resistance are obtained from the measurements of several points
on the I-V curve and then using these parameters the entire I-V curve is plotted using equations
representing appropriate models. The knowledge of these parameters in itself is highly important
for studying solar cells and for the design and manufacture of the solar cells. The effect of various
environments like charged particle environment and the impact of solar array arcing have been
seen to impact some or all of these parameters.
Diffusion current is characterized by an ideality factor equal to one and it varies with forward bias
Vj and temperature T following the expression given by [1]
This double diode model has been in use for obtaining solar array currents at different voltages and
intensities and aspect angles by people working in the area of solar arrays especially those in space
industry. The accuracy of this model is found to lie within 1 to 2% for space quality silicon and
gallium arsenide solar cells. Although this model is very attractive, the actual calculation of the
two components of the reverse saturation current as well as the series resistance and shunt
resistance is not easy. It is also not possible to directly apply a least squares method because of the
non linear nature of the problem. This problem is compounded by the fact that we have to solve
implicit equations also.
This problem has been attacked from different angles by different authors. S. Mottet[2] has given a
least-square solution of the problem. Since the solar cell equation is implicit, the solution is not
straightforward, but uses iteration procedure for estimating the series resistance. Sharma et. al. [3]
have employed an analytical solution to the problem. However, the equations in this method are
complicated and in practice, the analytical solution is not straight forward and the use of software
is usually required. Another limitation of this method is that the light generated current is assumed
to be equal to the short-circuit current and shunt resistance is totally neglected. Recently, Suresh
Puthanveettil [4] has suggested a spread sheet solution to the problem. Even though the light
generated current appears as an output, here again shunt resistance is totally neglected.
3. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
27
Genetic Algorithms belong to the group of evolutionary computation methods. These are adaptive
search algorithms used to tackle optimization problems. These algorithms are heuristic in nature
and the search is conducted by creation of generations of solutions. The search is refined by
information gained from previous generations. The fitness of each solution is computed and the
final solution is based on the principle of the survival of the fittest as in Darwin‟s theory of
evolution.
In the present paper, we employ Genetic Algorithm to solve the problem and to arrive at
the parameters defined above. There are several advantages to Genetic Algorithm. One is
that a full search of the solution space is not required. Another advantage is that this
software can be easily adapted for a more general equation of the
form
I(V)=IL-I01{exp [(V+IRs)K/mT] –1}- I02{exp [(V+IRs)K/2nT] – 1} -(V+IRs)/Rsh (5)
where m and n are new parameters which may sometimes be necessary for more accuracy.
Similarly, the dark cell I-V measurement can be used directly without altering the software
to estimate all parameters except the light generated current. In fact to the best of our
knowledge the first use of genetic algorithm for solar cells was made by Okumura et al.,
[5] to obtain the parameters of solar cell under dark condition employing a single diode
model of the form
I(V)=I01{exp [(V+IRs)K/mT] –1} -(V+IRs)/Rsh (6)
2. ALGORITHM
The algorithm can be broken down into the following steps
i.Generation of initial population is done by random number generation. The number of initial
population is chosen as 1000 in our case, but this number can be varied depending on the choice
of the user. Each parameter like the light generated current, series resistance and so on are
represented by a 16 bit binary number( The number of bits can be increased for more accuracy).
This binary number is converted to decimal number and the value for each of these parameters
is calculated by dividing the range of (the difference between upper and lower limits) of the
variables which are chosen initially in a logarithmic fashion.
ii.The fitness of the first and other generations are calculated by comparing the I-V curve
generated from the solution to the experimental values by least squares. The one where the sum
of the least squares is minimum is ranked as one, the next one as two and so on.
iii. The next generation is created by choosing the parents and creating offsprings. Here we have
allowed only the first 30% of the population (arranged rank wise) to
create off-springs. The off-springs are created by crossing over of the bits of the father and
mother after a certain bit which is randomly chosen. We have also used the principle of elitism
by retaining the first five ranks in the next generation without change.
iv.A small percentage of the bits are randomly altered (to effect mutation) so as to increase
diversity.
v.The ranking, selection of parents, reproduction, selection of elites and mutation are repeated for
each generation.
vi.A total of 100 generations is created and the first rank of the last generation is chosen as the
fittest solution.
4. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
28
3. RESULTS AND ANALYSIS
The first analysis we have carried out with this software is with imaginary Silicon 2 ohm-cm solar
cell with the following parameters which are given in Table1.
Table 1. Input parameters for obtaining the current-voltage characteristics of a simulated solar cell
Parameter Value
IL 1.00 amp
I01 1x10
-10
amp
I02 5x10
-7
amp
Rs 0.025 ohm
Rsh 1000 ohm
Using these parameters we have calculated the I- V characteristics of the solar cell. Using these
current and voltage values as input, we have run the genetic code to get back the parameters and
the results are given in Table2.
Table 2. Output parameters of the simulated solar cell of Table 1. obtained through genetic algorithm
Parameter Value
IL 0.9999 amp
I01 1.1184x10
-10
amp
I02 4.958x10
-7
amp
Rs 0.02488 ohm
Rsh 980 ohm
From this table we understand the most of the parameters can be known very accurately if the
input current and voltage values are measured properly. There is some inaccuracy as far as I01 is
concerned which here is about 12%. Shunt resistance inaccuracy is about 2% and all other errors
are minimal. This gives an indication of the accuracy of this method of estimating the parameters
given in Tables 1 and 2.
Next, we have used the developed software to analyze 10 ohm Si solar cells of nominal
dimension 2cm x 4cm before and after radiation to a fluence level of 3x1013
electrons/cm2
. The
cell types are both BSR type cells. Figure.1 gives the I-V characteristics of unirradiated BSR cell
at 28°C. The I-V characteristics of the same cell irradiated to a fluence of 3x1013
1
MeVelectrons/cm2
at 28°C are given in Figure.2. The experimental data is represented by discrete
points and the data according to our theory is presented as a continuous line in both the cases.
This continuous line is generated using the parameters evaluated using genetic algorithm. In both
of the above, one can notice the close match that exists between theory and experiment. It is to be
noted that the experimental data were obtained by using the standard facilities and methods used
in space industry.
The results of the parameters evaluated are tabulated below:
5. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
29
Table 3. Output parameters of a silicon solar cell before and after electron irradiation obtained through
genetic algorithm
Parameter Value before irradiation Value after irradiation
IL 0.31819 amp 0.31012 amp
I01 8.86168x10-11
amp 1.2437x10-10
amp
I02 6.4422x10-7
amp 9.46299x10-7
amp
Rs 0.0561 ohm 0.0539 ohm
Rsh 531.8 ohm 632.4 ohm
It is seen that the light generated current decreases, I01 and I02 both increase as expected. There
is no remarkable change in series resistance and we believe that the apparent increase in shunt
resistance also is due to the limitations of the model or method rather than a real increase in shunt
resistance.
Further, we have compared the dark and illuminated characteristics of a silicon solar cell and
the result is given in Table below.
Table 4. Output parameters of a silicon solar cell in dark and under illumination obtained
through genetic algorithm
Parameter Value for cell not illuminated Value for illuminated cell
IL 1e-20 amp 1.0690 amp
I01 1.4329x10-10
amp 1.3395x10-10
amp
I02 3.1619x10-7
amp 4.869x10-7
amp
Rs 0.025148 ohm 0.023355 ohm
Rsh 447.2 ohm 945.2 ohm
There is a good match between the two values of I01 and Rs. Both the values of I02 are
comparable, but not quite identical. The differences can be due to measurement inaccuracy
and the limitations of the model.
We have also used the developed software to analyze the following types of solar cells and
the results are given below.
i. GaInP solar cells
ii. (In)GaAs solar cells
iii.Ge solar cells
Table 5. Output parameters of a GaInP solar cell in under illumination obtained through genetic algorithm
Parameter Value
Isc(measured value) 0.50798 amp
Voc(measured value) 1.3961V
IL 0.508875 amp
I01 1.9989x10-25
amp
I02 9.87147x10-13
amp
Rs 0.043591 ohm
Rsh 192.7 ohm
6. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
30
Table 6. Output parameters of an (In)GaAs solar cell in under illumination obtained through
genetic algorithm
Parameter Value
Isc(measured value) 0.55074 amp
Voc(measured value) 1.0305V
IL 0.5505 amp
I01 2.359x10
-18
amp
I02 3.5898x10
-10
amp
Rs 0.053179 ohm
Rsh 9999 ohm
Table 7. Output parameters of a Ge solar cell in under illumination obtained through genetic
algorithm
Parameter Value
Isc(measured value) 0.84733amp
Voc(measured value) 0.2474V
IL 0.85929 amp
I01 2.766x10
-5
amp
I02 4.4109
-
x10
-3
amp
Rs 0.02306 ohm
Rsh 199.98 ohm
The three cells mentioned above comprise the sub-cells of triple junction solar cells usually used
in the space industry. In all the cases, it is seen that the light generated current is nearly equal to
the short circuit current as expected.
Next, we have compared the results of the parameters generated by the method of Puthanveettil to
the method employing genetic algorithm. It can be seen that there is very good agreement
between the parameters estimated by both methods wherever applicable.
Table 8. Output parameters of a silicon solar cell under illumination obtained through the
spread sheet method and through genetic algorithm
Parameter Puthanveettil Genetic algorithm
IL 0.3180 amp 0.3182 amp
I01 8.106x10
-11
amp 8.862x10
-11
amp
I02 7.034x10
-7
amp 6.442x10
-7
amp
Rs 0.0626 ohm 0.0561 ohm
Rsh infinite 531.8 ohm
The last question which we addressed is the utility of genetic algorithm on the reproduction of the
current voltage characteristics of the solar cells. In all the cells which we have carried out the
study, the results show a very good match between the measure values and the values estimated
from the parameters like I01 and I02 which we have obtained using genetic algorithm. An
example is given in Figure 1 for a silicon BSR solar cell.
7. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
31
4. CONCLUSION
A method of calculating the solar cell parameters like the two different components of the reverse
saturation current and the series resistance, the shunt resistance and the light generated current
was developed using genetic algorithm applied to the experimental current voltage characteristics
of the cell. The data obtained were physical and the variations seen in the parameters due to
irradiation were as expected in the silicon solar cell. Similarly, the parameters except the light
generated current did not vary much when the illuminated and dark cell characteristics of the
same silicon cell were analyzed using genetic algorithm. The algorithm was used to analyze other
types of cells and there was very close match between values generated by genetic algorithm and
by another method proposed by Puthanveettil. The algorithm was applied to get back the solar
cell parameters from the characteristics of an ideal cell which was generated using the solar cell
equation from the solar cell parameters and the reproduction of values was seen to be very good.
There was close match between the current-voltage characteristics generated from the parameters
obtained by genetic algorithm and the original experimental values. All these point to the
adequacy of genetic algorithm to obtain the solar cell parameters.
REFERENCES
[1] H.Y. Tada, J. R. Carter, B. E. Anspaugh and R. G. Downing, "Solar cell radiation handbook", JPL
Publication 82-69
[2] S.Mottet,”Solar cell modellng for computer-aided design and irradiation degradation of generators”,
Photovoltaic generators in space, ESA-SP-147, Heidelberg, 1980.
[3] S. K. Sharma, D. Pavithra, N. Srinivasamurthy and B. L. Agarwal, "Determination of solar cell
parameters: an analytical approach", Journal of Physics D: Applied Physics, PP. 1130-1133, Vol. 26,
1993.
[4] Suresh Puthanveettil, “Prediction of full current-voltage characteristics of space silicon solar cells
from limited data by using a spreadsheet function”, Journal of Spacecraft Technology, Vol22,No2,
pp01-06,June 2012
[5] Teppei Okumura, Shunichiro Ninomiya, Hirokazu Masui, Kazuhiro Toyoda, Mitsuru Imaizumi,
Mengu Cho, „Solar cell degradation due to ESD for international standardization of solar array ESD
test‟ Proceedings of 10th Spacecraft Charging Technology Conference, published in CD, 2007,
Biarritz, France
AUTHORS
Suresh E. Puthanveettil obtained his Master‟s Degree in Physics from Brooklyn College
of the City University of New York where he was also teaching Physics and Astronomy.
After a brief stint as a lecturer in Physics with the Regional Engineering College, Calicut
(now National Institute of Technology), he joined the Solar Panel Division of ISRO
Satellite Centre, where he has been working for the last 29 years. Presently he is Head of
Solar Panel Division. His areas of major interest are solar panel design, fabrication and
testing, particle radiation estimation of satellites in general and solar panels in particular
and electrostatic discharge on solar panels. He has been invited to give talks on his work both in India and
abroad by educational institutions. He has guided several Master of Computer Application students for their
projects. He has translated „Gita Sadhana-a Samvit Stair-case‟, a book of great erudition in practical
Vedanta, from Hindi to English.
8. International Journal on Soft Computing, Artificial Intelligence and Applications (IJSCAI), Vol.5, No.1, February 2016
32
Mengu Cho received the B.S. and M.S. degrees from the Department of Aeronautics
and Astronautics, University of Tokyo, in 1985 and 1987, respectively, and the Ph.D.
degree from the Department of Aeronautics and Astronautics, Massachusetts Institute of
Technology, the United States of America, in 1992. From 1992 to 1995, he was a
Research Associate with Kobe University, Japan. From 1995 to 1996, he was a Teaching
Associate with International Space University, France. Since 1996, he has been with the
Department of Electrical Engineering and Electronics, Kyushu Institute of Technology,
where he was an Assistant Professor in 1996 and an Associate Professor in 1997 and has been a Professor
and also the Director of the Laboratory of Spacecraft Environment Interaction Engineering since 2004. He
has been with the Department of Applied Science for Integrated system engineering since 2010. His
research interest is spacecraft environment interaction, especially spacecraft charging, and small satellite
systems engineering.
Amrita Suresh is currently pursuing her Bachelor‟s Degree in Computer Science from
BITS Pilani K K Birla Goa Campus. She is doing her thesis at IIT Bombay, in Parallel
Algorithms and Circuit Complexity. She briefly interned with Intuit India, and worked in
the QuickBooks Development Team. She also interned in the Indian Space Research
Organization, in the Power Systems Group. Her research interests are Theory of
Computation, Algorithms, and Complexity Theory.