Model Of Photovoltaic Array Research Articles

Research on General Model and Parameter Characteristics of Photovoltaic Array

Under partial shading conditions, the P–U curve of PV (photovoltaic) array shows multiple local peaks. The traditional PV model cannot reflect this change. It is necessary to re-establish the mathematical model of the PV array suitable for complex lighting conditions. Based on the mathematical model of double diode PV cells, combined with the series–parallel theory of circuits, a detailed analysis of photovoltaic arrays under partial shading conditions is carried out, and the mathematical model of PV arrays under partial shading conditions is theoretically deduced by piecewise functions. The proposed general model is tested for irradiance intensity, temperature, and diode ideality factor and parallel resistance variable parameter sensitivity test in MATLAB. The output characteristics is tested and compared under uniform light and local shading conditions under random environment. The results show that the proposed model has good versatility and accuracy, and it can quickly and accurately reflect the I–U and P–U characteristics of PV arrays under complex lighting conditions under varying operating conditions, which provides strong support for related research on large-scale PV power generation systems.

Temperature Analysis of the Stand-Alone and Building Integrated Photovoltaic Systems Based on Simulation and Measurement Data

Sunlight is converted into electrical energy due to the photovoltaic effect in photovoltaic cells. Energy yield of photovoltaic systems depends on the solar array location, orientation, tilt, tracking and local weather conditions. In order to determine the amount of energy produced in a photovoltaic system, it is important to analyze the operation of the photovoltaic (PV) arrays in real operating conditions and take into account the impact of external factors such as irradiance, ambient temperature or the speed of blowing wind, which is the natural coolant of PV panels. The analysis was carried out based on mathematical models and actual measurement data, regarding the dependence of the average temperature of PV arrays on variable and difficult to predict ambient conditions. The analysis used standard (nominal operating cell temperature (NOCT)), King, Skoplaki, Faiman and Mattei thermal models and the standard model for flat-plate photovoltaic arrays. Photovoltaic installations PV1, PV2a and PV2b, being part of the hybrid power plant of the Bialystok University of Technology, Poland, were the objects of the research. In the case of a free-standing solar system, the Skoplaki model proved to be the best method for determining the average temperatures of the PV arrays. For building-integrated PV systems, a corrected value of the mounting coefficient in the Skoplaki model was proposed, and the original results were compared. The comparison of the accuracy measures of the average operating temperatures for three micro-power plants, differently mounted and located, is presented.

Research on Accurate Engineering Mathematical Model of PV Cells and Simulation Characteristics

It is an important basis for PV power generation and related technology research to establish an efficient and accurate photovoltaic (PV) array engineering mathematical model. For the difficult problem of traditional mathematical model of PV array to be solved, the engineering mathematical model of PV array is derived based on PV cell single diode model. The diode ideal factor, series resistance, temperature and radiation intensity of PV array on the output characteristics of PV array influences are analyzed. The model is improved and the parameters are optimized, an efficient iterative method is proposed to calculate the series resistance and parallel resistance. On Matlab platform, the comparison of 4 solar cell material property parameters is tested to verify the accuracy of the proposed solution. The results are compared with the traditional Newton iterative method and approximate fitting line method in 5 random environments, the error can be within 6%. The simulation results show that the proposed model has better versatility and sensitivity, quickly and accurately reflects the I–U and P–U output characteristics of PV arrays under variable working conditions; it meets the requirements of engineering accuracy, and provides strong support for large-scale PV power generation system and related research.

A reinforcement learning based approach for on-line adaptive parameter extraction of photovoltaic array models

At present, most methods for the fault detection and diagnosis (FDD) of the photovoltaic (PV) array strongly rely on comparing the on-line measured electrical parameters with the modeled reference ones, which are challenging the on-line accuracy and time cost of the parameter extraction for modeling the current-voltage (I-V) curves of the PV array. In this paper, a reinforcement learning (RL) based approach for on-line adaptive parameter extraction of PV array models is proposed. The model parameters, including the ideality factor, series and shunt resistance, and the compensated irradiance for the uncalibrated pyranometer, are extracted. Corresponding environmental states, actions, rewards, and the entire framework for the on-line adaptive parameter extraction are reasonably designed and investigated. The annual experimental results verify that the proposed RL-based approach can obtain higher on-line accuracy for modeling the I-V curve of PV array with fast extraction speed, compared with the conventional meta-heuristic-based approach and the analytical approach for parameter extraction. The annual experimental results reveal that the proposed approach can guarantee the 50% probability for obtaining the root mean square error (RMSE) less than 0.1, and 90% probability for obtaining the RMSE less than 0.25. The average computational time cost of the proposed approach is approximate 38.12 ms. In addition, the annual trend of extracted model parameters is analyzed. The annual results also show that the series and shunt resistance have the inverse seasonal trend. Besides, the measurement error of the pyranometer can be identified statistically. The proposed RL-based approach can also be integrated with the presented on-line FDD method, which realizes the on-line training of RL agents and the FDD of PV array simultaneously.

Modeling PV installations under partial shading conditions

This paper deals with the development of a photovoltaic (PV) array model under partial shading conditions. Based on the one diode equivalent circuit of a PV cell, and mathematical developments proposed in literature, the authors propose a simple and accurate model of PV arrays under partial shading conditions. First, the equations to calculate the needed I–V curve parameters are presented. Then, the paper synthesizes a simple implementation of these equations on MATLAB software. In order to validate the author’s propositions, experimental results are carried out on two parallel connected 180 W PV modules. Each module has 72 mono-crystalline cells, connected in series and organized in 3 cell strings. Each cell string has 24 cells and is protected by one bypass diode. The simulation and experimental results aim to prove the performances of the proposed modeling methodology of the PV module and/or array when partially shaded.

A Solution of Implicit Model of Series-Parallel Photovoltaic Arrays by Using Deterministic and Metaheuristic Global Optimization Algorithms

The implicit model of photovoltaic (PV) arrays in series-parallel (SP) configuration does not require the LambertW function, since it uses the single-diode model, to represent each submodule, and the implicit current-voltage relationship to construct systems of nonlinear equations that describe the electrical behavior of a PV generator. However, the implicit model does not analyze different solution methods to reduce computation time. This paper formulates the solution of the implicit model of SP arrays as an optimization problem with restrictions for all the variables, i.e., submodules voltages, blocking diode voltage, and strings currents. Such an optimization problem is solved by using two deterministic (Trust-Region Dogleg and Levenberg Marquard) and two metaheuristics (Weighted Differential Evolution and Symbiotic Organism Search) optimization algorithms to reproduce the current–voltage (I–V) curves of small, medium, and large generators operating under homogeneous and non-homogeneous conditions. The performance of all optimization algorithms is evaluated with simulations and experiments. Simulation results indicate that both deterministic optimization algorithms correctly reproduce I–V curves in all the cases; nevertheless, the two metaheuristic optimization methods only reproduce the I–V curves for small generators, but not for medium and large generators. Finally, experimental results confirm the simulation results for small arrays and validate the reference model used in the simulations.

Active distribution system state estimation incorporating photovoltaic generation system model

The inherently intermittent and varying power generation of distributed energy resources (DER) makes the situational awareness of active distribution systems (ADS) a challenging issue. Considering the detailed photovoltaic (PV) system model and environmental influencing factors including solar irradiance and temperature, this paper develops a state estimation model for the ADS with integrated PV power generation systems. Firstly, in order to achieve high computational efficiency, an explicit function fitting model of PV arrays is proposed and used to accurately approximate the conventional five-parameter model. Then, the state variables of a PV generation system are selected, and the measurement equations and the Jocobian matrix are derived. Finally, combined with the conventional distribution network model, state estimation and bad data processing of an ADS with PV systems are realized. A generalized per unit system is also developed for unified standardization of electrical and non-electrical quantities. Simulation results in the IEEE 33-bus system show that the proposed model significantly expands the scopes and capabilities of state estimation and bad data processing in ADSs, which facilitates comprehensive and reliable monitoring of ADSs.

Comprehensive Modeling of Large Photovoltaic Systems for Heterogeneous Parallel Transient Simulation of Integrated AC/DC Grid

Detailed nonlinear transient modeling of the photovoltaic (PV) system enables an accurate study of the host integrated AC/DC grid. In this article, the parallel architecture of the graphics processing unit (GPU) catering to a massive number of PV modules is utilized in conjunction with CPU for efficient transient simulation. To reflect the exact operation status of the solar power system subjected to various temperatures and nonuniform solar irradiance in the electromagnetic transient (EMT) simulation, all necessary panels are modeled individually, and therefore, a scalable PV array model with a flexible level of aggregation is proposed in addition to its fully detailed discrete counterpart so as to improve the computational efficiency. The single-instruction multiple-thread implementation mode of the GPU enables up to 10 million PV panels, regardless of the size or type, to be computed concurrently, and noticing that the hybrid AC/DC grid has a significant irregularity, the CPU is also adopted to tackle systems with inadequate parallelism. Meanwhile, since the AC grid dynamic interaction has a distinct tolerance on the time-step to that of the remaining part, a multi-rate scheme is employed to expedite the heterogeneous CPU-GPU computation for dynamic-EMT co-simulation, whose results are validated by the commercial off-line tools MATLAB/Simulink and DSATools/TSAT.

Application of Artificial Intelligence Techniques for Modeling and Simulation of Photovoltaic Arrays

A method for modeling photovoltaic (PV) arrays - based on artificial intelligence techniques, namely genetic algorithm (GA) and cuckoo optimization algorithm (COA) - is presented. COA and GA are used to obtain the parameters of the PV array model using the PV cell’s datasheet information. The adopted models – using GA and COA - are implemented on a simulation platforms using MATLAB 2020a environment for two-diode and single-diode models. The proposed optimization method fits the mathematical current-voltage (I-V) characteristic to the three (V, I) remarkable points without the need to guess or to estimate any other parameter. The obtained models are tested and validated with experimental data taken from the Mutah university’s PV power plant. The results show that for both of the employed optimization algorithms, the two-diode model is more accurate than the single-diode model. The results also disclose that, at different values of temperature and solar irradiance, the COA – compared to the GA – better handles the optimization problem with low iterations and better fitness value.

Impact of Partial Shading on Various PV Array Configurations and Different Modeling Approaches: A Comprehensive Review

Since the last decade, partial shading conditions (PSCs) and its adverse influences on photovoltaic (PV) system performance have received due attention. It motivates researchers to explore methods to diminish/disperse the shading effects and/or novel PV array configurations to sustain under PSCs. To diminish the effects of PSCs, this article presents a comprehensive review of various PV array configuration models for PV systems and metaheuristic approaches for shade dispersion effectively. Different PV array modeling approaches are identified, emphasizing their benefits, inadequacies and categorized according to vital features such as shade dispersion and improved performance in terms of efficiency; fill factor (FF), and maxima power, minimized power losses (PL) primarily. Besides these various PV array configurations such as hybrid, reconfigured, mathematical/game puzzle based advanced configurations are uniquely discussed with the existing configurations. In the current scenario, the metaheuristic algorithms are explored and widely accepted by researchers due to the less wire length requirement for PV array reconfiguration. This article discusses and deliberates recent developments in methods of solar PV performance enhancement that deserves further study. Overall, the present study is helpful for academicians and researchers in the committed solar power installation area.

Droop Control Based Grid-Connected Solar Photovoltaic Inverters for Distributed Generation

In day to day the demand of electrical energy has been increasing in worldwide, as well the share of solar photovoltaic power generation has increased extremely because of population growth, urbanization, etc. Although the power generated from solar photovoltaic is erratically, and it makes the stability and reliability problems in a utility grid. This paper projects a P/Q droop control strategy for a grid-tied PWM inverter. This paper introduces an entire model of grid-connected solar photovoltaic array; inverter with droop control, and loads are developed for this operation. The locus points of the both power sharing of the DG system is developed by the proposed control operation. PI controllers were used in this droop control was espoused to adjust the constraints of PI controller. The results of the proposed droop control inject positive and reactive power into a variation of loads and improving the quality of power as compared to the conventional PID controllers.

Modeling and Simulation of Disturb and Detect Maximum Power Point Tracking Algorithm for Standalone Solar System

Modeling and simulation of photovoltaic (PV) module is presented in this work using Matlab/Simulink environment. The simulated PV array model will consider the temperature and irradiance as variable parameters inputs and I-V, P-V characteristics as outputs. Algorithms designed in this paper to achieve the maximum power point (MPP) at all time. DC-DC boost converter has been calculated and designed in this work. Analysis and study of the PV system and MPPT performance with variable parameters under transient conditions.

Modeling Of Pv Array For Dc-Dc Flyback Converter With Asymmetrical Output Voltage

This paper manages the modeling of PV(Photovoltaic) array for Flyback converter (FBC) with Asymmetrical voltage. The Solar PV system is fed with Flyback converter on transformer in primary side. The MOSFET switch is controlled by using Maximum power tracing system with the switching frequency of 65KHz. The Petrub and Observe algorithm is utilized in the system for controlling the switch in the converter. The Output of Flyback converter with four different asymmetrical output voltage. The input FBC is 24V and output FBC is 6.3 Vdc,12.6 Vdc,26.2 Vdc and 52.4 Vdc respectively. The output capacitor is used for filter the pure DC output voltage of this system. The asymmetrical output voltage is used for Asymmetrical multilevel inverter. The system is design in MATLAB and overall system is implemented in real time system suing ARDUINO Controller, MOSFET driver circuit and ferrate core transformer.

An Improved P&O Algorithm for Single-Stage Grid-Connected Photovoltaic System under Rapidly Changing Environment Conditions

In producing its power, Photovoltaic (PV) performance is influenced by environmental factors, such as solar irradiance and temperature. System stability is needed to maintain safe operation of the system. This paper presents a Maximum Power Point Tracking (MPPT) control model of PV array to improve system reliability and the performance of MPPT. The main parameters in Matlab/Simulink simulation that become the highlight influences are the changes in solar irradiance from 500W/m2 to 1000W/m2 and ambient temperatures from 25°C to 50°C. With the control algorithm that has been made in the Perturb and Observe (P&O) method, it obtains the optimal voltage control point in each PV conditions in a power system. System simulation shows that the voltage stability was maintained above 510 Volt in various conditions of solar irradiance and temperature. The results of the control scheme show the stability of the system and the optimal performance of PV.

Statistical sensorless short-circuit fault detection algorithm for photovoltaic arrays

One of the main challenges for the conventional protection system of a photovoltaic (PV) array is the occurrence of light fault conditions including a low location mismatch fault, a fault with a high fault path resistance, and a fault under low solar irradiance because the fault current increment is not enough for triggering current-based protective devices. The operation of the maximum power point tracking system and utilizing blocking diodes may also result in a light fault condition. An undetected fault condition causes a potential fire hazard and energy loss. This paper proposes a waveshape based statistical fault detection algorithm for light fault detection. The proposed algorithm quantifies the waveshape tailedness of superimposed PV array power by the kurtosis function. The proposed algorithm is able to discriminate the light fault condition from severe partial shading and is also effective for open-circuit faults. In addition to no need for additional sensors, it does not require a training dataset and prior information about the PV array. The merits of the proposed algorithm are corroborated through several case studies on a simulation model of a test PV array considering the parameter uncertainty and the presence of noise in the signals.

Analysis of attitude planning and energy balance of stratospheric airship

Solar energy is an essential energy source collected by photovoltaic (PV) cells for long-endurance stratospheric airships. Attitude control is crucial for the energy production of the PV array attached to the airship hull. This study was conducted to analyze the energy balance of stratospheric airships with attitude planning. A solar radiation and PV array model is proposed, then a steerable attitude strategy is established considering the roll, pitch, and yaw control of the PV array. The energy balance of the model is analyzed under an attitude planning scheme based on an actual airship design. The daily net energy of the airship is calculated according to monthly wind data of various latitudes. The influence on the net energy considering the conversion efficiency of PV cells and specific density of the energy stored system (ESS) is also analyzed. The results shows that attitude planning has a significant effect on both the energy production and wind resistance of the airship. The energy balance of the airship is markedly improved when PV conversion efficiency is high and ESS energy capacity is large. The results presented here may prove valuable for future stratospheric airship applications.

Development of a dynamic model for photovoltaic modules and arrays

In the work, a dynamic model is proposed in Simulink, to model the behavior of photovoltaic modules and arrays. A novel methodology is proposed to obtain exactly the five parameters of the simple diode model, through the data provided by the manufacturer in the data sheet. The model proposes the calculation of the Volt-Ampere curve from environmental conditions, solar irradiance, ambient temperature and second-order effects, such as: the influence of temperature on the photocurrent generated and on the open circuit voltage, as well as the spectral and optical effects. The validity and accuracy of the proposed model is checked by comparing its results, with curves and experimental data from the manufacturer's data sheet. In addition, curves of the module are shown, allowing to evaluate its behavior taking in to account the optical and spectral effects.

Lithium-ion energy storage battery in PV-smart building application

Photovoltaic (PV) panels with energy storage batteries represents a feasible solution for powering domestic loads. The service life of the batteries and the power management are the main challenges by developing the energy supply system of smart homes. Therefore, in this paper an efficient algorithm is developed in order to power a house by extracting the maximum power from the PV panels, enhancing the battery service life and minimizing the power supply from the smart grid. The smart metering, advanced inverter and rule-based energy management strategy ensure safe and optimal operation of the energy supply system. Matlab/Simulink model of typical PV array, lithium-ion battery, inverter with the associated controllers are developed to evaluate the performance of the proposed system. Starting from the actual solar irradiance data, the maximum power of PV array will be extracted as a function of the available irradiance and ambient temperature. The daily battery state of charge (SOC) and its internal temperature are calculated depending on the load, PV power and the battery charge/discharge modes. Simulation results show that the proposed algorithm can enhance the performance of energy supply system, extract the maximum solar power and minimize the power from smart grid. Key words PV array, MPPT controller, Li-ion storage battery, energy management, hybrid power system.

A comprehensive state-space model of two-stage grid-connected PV systems in transient network analysis

The large-scale deployment of distributed photovoltaic (PV) systems on the low voltage distribution network (LVDN) poses significant challenges to network operators related to the dynamic interactions of the PV systems and the network. To address these challenges and implement grid support services (GSS’s), accurate and efficient PV system models are required that allow large networks with integrated PV to be simulated in an economical time frame. For this purpose, an accurate, computationally inexpensive, linearised, state-space model of a two-stage PV system in the dq0 rotating reference frame is presented in this paper. The model includes both the DC/DC and DC/AC converters, all system controllers, parasitic components, system losses, and an efficient PV array model. The performance of the model is validated with measured experimental data from a power hardware in the loop (PHIL) testbed at various simulated step changes in irradiance. The developed model is applied to a modified radial European LVDN benchmark with multiple distributed PV systems to demonstrate some of the functions, applications and advantages. A combined active and reactive power voltage-dependent droop control characteristic for GSS’s is demonstrated with solar irradiation step changes and measured solar irradiation data applied to each PV system. A full electromagnetic transient (EMT) PV system model developed in MATLAB is presented and compared to the linear state-space (LSS) model. The results demonstrate a computational burden reduction of 116:1 without loss of accuracy providing significant benefits and functionality for the study of large-scale grid integration of PV systems.

Correntropy‐based parameter estimation for photovoltaic array model considering partial shading condition

Analytical modelling of photovoltaic (PV) array is crucial for studying the current–voltage (I–V) characteristic of PV array and maximum power point tracking. A PV array model generally contains some undetermined parameters and the values of the parameters cannot be measured by sensors. It is difficult to correctly determine those model parameters. They should be estimated based on experimental data. Since the experimental data gathered from the solar panel equipment usually contain random and gross errors, a robust parameter estimation method, correntropy-based parameter estimation (C-PE) is proposed for PV array model considering partial shading condition here. First, the theoretical model of PV array considering partial shading condition is investigated. Second, compared with the most common estimator, weighted least squares (WLS), robustness of the proposed correntropy estimator is analysed by using influence function (IF), and then C-PE method is developed for the PV array model. The WLS-based parameter estimation (WLS-PE) and C-PE methods are used in the simulation example. The results show that the C-PE method is more robust than WLS-PE method. Finally, the experimental data of PV array under ideal condition and partial shading condition are also used to demonstrate the feasibility and effectiveness of C-PE method.