Radiação solar: estudo e criação de plataforma de apoio à conceção de um sensor de radiação solar

Este trabalho apresenta os resultados de uma plataforma de simulação da radiação solar. A plataforma de simulação apresentada permite simular radiação solar através de dados medidos ou dados históricos. Para utilização dos dados históricos, apresenta-se o instrumento Environment Simulator que juntamente com a base de dados meteorológicos permite obter variáveis meteorológicas para qualquer posição e tempo. Os resultados da utilização da plataforma de simulação de radiação solar foram comparados com os valores medidos durante na campanha ALEX2014

Analysis of Noise with Curve Fitting Method of a PV cell

Solar photovoltaic technology is a major contender in the race for renewable, sustainable and green energy.This paperintroduces the characteristics of different PV cell equivalent circuit and its output behaviour. It describes and implements the proposed characterization method by using a selected model. It generates I-V and P-V curve usingiterative method. Noise analysis and observation of curve fitting are briefly described here.The white noise effect and its related output characteristics are explained too. To introduce and implement the generalized method, a photovoltaic electrical equivalent circuit is used here. The fundamental equation of a PV cell is used to study the model and to analyze the best fit of observed data. The values of ideal parameters are used to study the model’sbehaviour. The main objective is to measure the noise in data approximation and on the polynomial curve fitting method for both the I-V and P-V curve.ERASMUS MUNDUS LEADER PROGRA

MATHEMATICAL MODELLING AND SIMULATION TECHNIQUES REVIEW FOR HYBRID PHTOVOLTAIC THERMAL SYSTEM

In this work, solar hybrid photovoltaic thermal (PVT) panel’s different mathematical modelling and simulation techniques are described. Mathematical and thermal model development and simulation technique is considered as the initial conditions to simulate the system’s behavior. This article discusses about improved modelling and implementation technique of hybrid PVT technology to enhance the panels effective efficiency by increasing energy output. Characterization and parameters identification including sensitivity analysis by using adapted numerical methods is studied and analyzed. Different types of simulation models are reviewed to establish by analyzing mathematical, thermal and physical model with advance computational tool

Modelling for classifying different shadow of obstacles on a c-Si PV panel

Shadow of Obstacles (SoO) on a PV Panel is classified depending on time with changing pattern of the shadow. Due to obstacles, the performance of a silicon c-Si PV panel reduces by a significant level. Different types of obstacles cast shadow on the panel and interrupt to get irradiation reducing the generated power. The simulation model is implemented in Matlab/Simulink to observe the changing pattern and variation of output power with changing shadow pattern of the obstacles. The results show identical behaviors. It is clearly viewed in both PV generated I-V and P-V curves. Their pattern of graphs is changed depending on the time for time-dependent obstacles. Graphs pattern is also changed with depending on time-independent obstacles and that does not vary with time. The identification of the behavior of the obstacle is vital to improve the PV system performance

A Comparative Review on Cooling Techniques to Develop Hybrid PV/T Panel

Renewable energy will be the leading source of power on the upcoming days. Solar irradiation is one of the most convenient sources due to abundance in nature. Right now scientist are facing challenges to mitigate the heat induced by the solar panel during the conversion process. Excessive heat degrades the electrical property of photovoltaic panel thus resulting in reduced efficiency. To improve the efficiency different cooling techniques have been introduced namely active and passive cooling. It is really important to select the right cooling technique while developing the PV panel. It is found that, passive cooling technique is more preferable in-terms of operating cost, ease of use and reliability

Analysis of a Non-Iterative Algorithm for the Amplitude and Phase Difference Estimation of Two Acquired Sinewaves

In this paper, a non-iterative algorithm for amplitude and phase difference estimation of two acquired sinewaves is presented and analyzed. The method is based on the least-squares fitting of ellipses where the common signal frequency is eliminated from the algorithm

A New Approach of Total Least Square Algorithm for Parameter Extraction of a Photovoltaic Panel: A Comparison Study

The degradation of the photovoltaic panels due to their long outdoor exposure leads to a variation in their internal parameters. The function describing the I-V characteristic of the photovoltaic cell is known to be non-linear and implicit, with five unknown parameters. To identify these photovoltaic parameters, the cost function used for optimization is the Total Least Square function (TLS), defined as a sum of quadratic terms representing the quantification of the errors between a mathematical model and a measured set of experimental data, which is usually accompanied by measurement uncertainties (measuring current and voltage). However, the studies that have been done so far to extract the photovoltaic parameters work with the Ordinary Least Square (OLS) function defined as the sum of quadratic terms representing the quantification of the errors between a mathematical model and a measured set of experimental data of one variable (current only), because it is facile to apply, especially in the case of nonlinear models. Nether less, taking into account both differences in measurement uncertainties accompanying both variables will help to achieve more efficient optimization and more precise results. This work presents a new iterative, simple to implement algorithm that can calculate the value of the Total Least Square function at each step of the optimization process. The results are then compared with the ones obtained by applying the OLS function

Non-iterative MPPT Method: A Comparative Study

The presented work is a contribution to maximum power point tracking problem with improved performance. The analysed and discussed method is based on mathematical model of a PV panel. The output power of PV panel is dependent on the load as well as the almost unpredictable behaviour of the environment. It has a non-linear implicit behaviour on the load due to the weather parameters dependency. Due to different conditions of PV curve, it may have several local maxima. Existing MPPT techniques are mainly based on iterative method which are more time consuming and complex in nature considering the sense of comparative techniques. The most used approach is based on P&O algorithm with gradient comparison. The proposed technique improves the performance on the basis of time and computational complexity. During a low changing environmental condition this method achieves good result on the way to reach the overall point for maximum power. Taking into account the data sheet values of the panel along with the usage of existing knowledge from the datasheets, this technique is possible to implement and flexible for digital signal processing platform. An experimental setup is also done to verify the accuracy, robustness and simplicity of the introduced algorithm. It is found that the proposed technique is less complex and can be coupled with other method too

Modeling and Sensitivity Analysis of Hybrid Solar System

Efficiency in the solar energy system is obtained by studying, modeling and analyzing the emerging hybrid photovoltaic thermal (PVT) technology that produces simultaneous electrical and thermal energy [1]. This paper describes the study and analyses of mathematical [2] model including thermal and electrical modeling [3-4] to obtain the effective efficiency of the hybrid photovoltaic thermal system.The important and efficient task is to investigate the parametric analysis of the hybrid PVT as it is combined with non-linear equations with high complexity. Environmental conditions and other related parameters have a great influence in the output of the hybrid PVT system [5]. A sensitivity analysis [6] of the parameters variation is briefly described and conducted to study the influence in this work. It is also studied and observed the thermal and electrical efficiency due to the effects of parameters variation. From the result, it is found that there is a great impact on the overall energy output including electrical, thermal and overall efficiency of the PVT module

Temperature Impact and Efficiency Analysis of Hybrid PVT System

Hybrid photovoltaic thermal (PV/T) systems are a type of solar system that combines the functions of a photovoltaic and a solar thermal in one unit [1]. The PV panels generate electricity from sunlight, while the thermal collection system captures the excess heat produced by the PV panels and uses it to produce warm water or space heating [2]. According to the recent analysis, the efficiency of the solar energy production in particular solar photovoltaic system is still low [3]. There are several factors to be considered that affect the energy production during the operation of hybrid PVT system. There are several internal and external or environmental parameters are responsible for this output disruption. The parameters found to be affecting are solar irradiance, environmental and module surface temperature, humidity, wind speed, shading, dust and many others [3]. Solar irradiance and temperature are the key role-players among all the variables. The light intensity or solar irradiance value is related with PV production as it affects short circuit current of the absorbed photons in the semiconductor material. The most important parameter which is the main concern of this work is the inside and outside temperature of the panel. If there is rise in ambient temperature, then the short circuit current only increases that results in decrease in power output [3-4]. As a result, the maximum power point (MPP) also decreases with the rise of temperature. Temperature is considered as a negative parameter in the panel, but it turns into positive in the proper use of hybrid PVT system. In this work, the impact of temperature rises in the panel and its related power output is shown which clearly identifies the negative result on the panel. Additionally, the MPP output due to temperature rise is also explained in the figure. Afterall, the changes in efficiency due to the temperature rise also analyzed in this work. One of the main advantages of hybrid PVT system is that it helps to regulate the panel temperature that tends to improve its efficiency. The PVT system can keep the panels cooler with high efficiency by capturing and using the excess produced heat. Temperature can be regulated in a PVT panel using several methods which will improve overall efficiency. Thus how, the PVT panel will be cooled producing more electric energy including thermal energy. This work proves that the impact of temperature rise can be mitigated, and efficiency is improved using hybrid PVT system properly