A Novel Model for Daily Energy Production Estimation of Grid-Connected Photovoltaic System

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Li Fen ◽  
Yan Quanquan ◽  
Duan Shanxu ◽  
Zhao Jinbin ◽  
Ma Nianjun ◽  
...  

The rapidly growing markets for distributed and centralized grid-connected photovoltaic (PV) systems require the reliable and available information for reflecting and predicting the electricity generation of PV systems. In this work, the relationship between PV energy production and meteorological environmental factors is discussed by correlation analysis and partial correlation analysis. Meteorological data available, including the clearness index, diurnal temperature range, the global radiation on horizontal surface, and etc., are used as inputs. Then, according to factor analysis, these various interaction factors are extracted as two independent common factors. Finally, a new method based on factor analysis and multiple regression analysis has been developed for estimating the daily PV energy production. The meteorological data are collected from Wuhan Observatory, and power data from a roof grid-connected PV system located at Huazhong University of Science and Technology in Wuhan. The data of the whole year (from March in 2010 to February in 2011) has been used for model calibration and the following data of March in 2011 is used to test the predictions. The results show that there is significant positive correlation between the estimated values and the measured values; the rMBE per day is −0.14%, MAPE per day is 13.60% and rRMSE per day is 18.04%.

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
A. Charki ◽  
R. Laronde ◽  
D. Bigaud

This article presents a method developed for carrying out the energy production estimation considering the energy losses in different components of a photovoltaic (PV) system and its downtime effect. The studied system is a grid-connected photovoltaic system including PV modules, wires, and inverter. PV systems are sensitive to environmental conditions (UV radiation, temperature, humidity) and all components are subjected to electrical losses. The proposed method allows obtaining the production of photovoltaic system and its availability during a specified period using meteorological data. The calculation of the production takes into account the downtime periods when no energy is delivered in the grid during this period. The time-to-failure and the time-to-repair of photovoltaic system are considered following a Weibull distribution. This method permits to have a best estimation of the production throughout the lifetime of the photovoltaic system.


Proceedings ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 50 ◽  
Author(s):  
G. Almonacid-Olleros ◽  
G. Almonacid ◽  
J. I. Fernandez-Carrasco ◽  
Javier Medina Quero

In this paper we present Deep Learning (DL) modelling to forecast the behaviour and energy production of a photovoltaic (PV) system. Using deep learning models rather than following the classical way (analytical models of PV systems) presents an outstanding advantage: context-aware learning for PV systems, which is independent of the deployment and configuration parameters of the PV system, its location and environmental conditions. These deep learning models were developed within the Ópera Digital Platform using the data of the UniVer Project, which is a standard PV system that was in place for the last twenty years in the Campus of the University of Jaén (Spain). From the obtained results, we conclude that the combination of CNN and LSTM is an encouraging model to forecast the behaviour of PV systems, even improving the results from the standard analytical model.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3152 ◽  
Author(s):  
Huadian Xu ◽  
Jianhui Su ◽  
Ning Liu ◽  
Yong Shi

Conventional photovoltaic (PV) systems interfaced by grid-connected inverters fail to support the grid and participate in frequency regulation. Furthermore, reduced system inertia as a result of the integration of conventional PV systems may lead to an increased frequency deviation of the grid for contingencies. In this paper, a grid-supporting PV system, which can provide inertia and participate in frequency regulation through virtual synchronous generator (VSG) technology and an energy storage unit, is proposed. The function of supporting the grid is implemented in a practical PV system through using the presented control scheme and topology. Compared with the conventional PV system, the grid-supporting PV system, behaving as an inertial voltage source like synchronous generators, has the capability of participating in frequency regulation and providing inertia. Moreover, the proposed PV system can mitigate autonomously the power imbalance between generation and consumption, filter the PV power, and operate without the phase-locked loop after initial synchronization. Performance analysis is conducted and the stability constraint is theoretically formulated. The novel PV system is validated on a modified CIGRE benchmark under different cases, being compared with the conventional PV system. The verifications demonstrate the grid support functions of the proposed PV system.


Author(s):  
Mohammed Bouzidi ◽  
Abdelkader Harrouz ◽  
Tadj Mohammed ◽  
Smail Mansouri

<p>The inverter is the principal part of the photovoltaic (PV) systems that assures the direct current/alternating current (DC/AC) conversion (PV array is connected directly to an inverter that converts the DC energy produced by the PV array into AC energy that is directly connected to the electric utility). In this paper, we present a simple method for detecting faults that occurred during the operation of the inverter. These types of faults or faults affect the efficiency and cost-effectiveness of the photovoltaic system, especially the inverter, which is the main component responsible for the conversion. Hence, we have shown first the faults obtained in the case of the short circuit. Second, the open circuit failure is studied. The results demonstrate the efficacy of the proposed method. Good monitoring and detection of faults in the inverter can increase the system's reliability and decrease the undesirable faults that appeared in the PV system. The system behavior is tested under variable parameters and conditions using MATLAB/Simulink.</p>


2019 ◽  
Vol 9 (1) ◽  
pp. 141 ◽  
Author(s):  
Slawomir Gulkowski ◽  
Agata Zdyb ◽  
Piotr Dragan

This study presents a comparative analysis of energy production over the year 2015 by the grid connected experimental photovoltaic (PV) system composed by different technology modules, which operates under temperate climate meteorological conditions of Eastern Poland. Two thin film technologies have been taken into account: cadmium telluride (CdTe) and copper indium gallium diselenide (CIGS). Rated power of each system is approximately equal to 3.5 kWp. In addition, the performance of a polycrystalline silicon technology system has been analyzed in order to provide comprehensive comparison of the efficiency of thin film and crystalline technologies in the same environmental conditions. The total size of the pc-Si system is equal to 17 kWp. Adequate sensors have been installed at the location of the PV system to measure solar irradiance and temperature of the modules. In real external conditions all kinds of modules exhibit lower efficiency than the values provided by manufacturers. The study reveals that CIGS technology is characterized by the highest energy production and performance ratio. The observed temperature related losses are of the lowest degree in case of CIGS modules.


2018 ◽  
Vol 225 ◽  
pp. 04004
Author(s):  
Tan Dei Han ◽  
Mohamad Rosman M. Razif ◽  
Shaharin A. Sulaiman

Solar photovoltaic (PV) systems has the potential of supplying infinite electricity from renewable energy to rural areas around Malaysia. Various preterm failures happening frequently on the system lead to its drop in efficiency and breakdown. Lack of studies on the system in Malaysia hinders the development in terms of operation and maintenance. There is no proper documentation relevant to the premature failure of the system in Malaysia. The main objective of this project is to study the nature of premature failure of stand-alone solar photovoltaic system in Malaysia in order to improve the operation and maintenance of the system. The present study would provide reference for proper planning on operation and maintenance of the PV system. The study was conducted base on expert’s input and extensive literature survey. FMEA method and ISM approach are applied to analyze the data collected. Poor cooling system have the highest risk priority number. Poor workmanship is the least depending factor for premature failure to happen thus requires most attention. Highest driving force of premature failure is poor monitoring and maintenance. More focus should be given to these premature failure during the planning for operation and maintenance due to its severity and impact.


2011 ◽  
Vol 356-360 ◽  
pp. 2393-2398
Author(s):  
Qi Qi Wei ◽  
Bei Yue Tan

photovoltaic system, optimum tilted angle, siphon principle, water treatment Abstract. Based on the recent research at home and abroad and the local meteorological data, this study aims to determine the optimum tilt angle of the solar-cell array surface and the best month on the system to achieve the optimal design of PV system. Full mechanical automatic control system is designed by using lever principle and siphon principle to realize the purpose of all-day and maintenance-free operational situation. It can replace the motor control system and at the same time,enjoys reliability, low cost, long life and energy conservation. The indoor and local river data of the experiment shows that this system has an evident effect on water decontamination. Furthermore, comparing with traditional aeration system. It has many advantages, for instance, it can save more than 20 thousand and carbon emission can be reduced by 683 ton and other aspects.


2020 ◽  
Vol 12 (6) ◽  
pp. 2233
Author(s):  
Tamer Khatib ◽  
Dhiaa Halboot Muhsen

A standalone photovoltaic system mainly consists of photovoltaic panels and battery bank. The use of such systems is restricted mainly due to their high initial costs. This problem is alleviated by optimal sizing as it results in reliable and cost-effective systems. However, optimal sizing is a complex task. Artificial intelligence (AI) has been shown to be effective in PV system sizing. This paper presents an AI-based standalone PV system sizing method. Differential evolution multi-objective optimization is used to find the optimal balance between system’s reliability and cost. Two objective functions are minimized, the loss of load probability and the life cycle cost. A numerical algorithm is used as a benchmark for the proposed method’s speed and accuracy. Results indicate that the AI algorithm can be successfully used in standalone PV systems sizing. The proposed method was roughly 27 times faster than the numerical method. Due to AI algorithm’s random nature, the proposed method resulted in the exact optimal solution in 6 out of 12 runs. Near-optimal solutions were found in the other six runs. Nevertheless, the nearly optimal solutions did not introduce major departure from optimal system performance, indicating that the results of the proposed method are practically optimal at worst.


Author(s):  
T. NARASIMHA PRASAD ◽  
V. LAKSHMI DEVI

Solar energy has become a very potential new energy; Connected directly with grid-connected photovoltaic (PV) systems does not require bulk and lossy battery. Distributed generation and on-site supply of PV system reduces losses of transmission and distribution, and mitigates environment pollution. This paper establishes a Dynamic model of grid-connected PV system by Matlab/Simulink with d-and q-axis as coordinates which is synchronously rotating with the grid voltage to reflect the characteristics of the system accurately. Based on the accurate modeling system, optimum control and fault analysis are studied. The simulation and analysis verify the effectiveness of the proposed algorithm, and demonstrate that the proposed control system has good static performance.


Author(s):  
Carlos Andrés Ramos-Paja ◽  
Daniel Gonzalez-Motoya ◽  
Juan Pablo Villegas-Seballos ◽  
Sergio Ignacio Serna-Garces ◽  
Roberto Giral

The wide range of step-up and step-down input-output voltage characteristic of the Cuk converter makes it a good candidate to interface photovoltaic arrays in both classical and distributed maximum power point tracking systems. Because its two inductor structure, Cuk converters have continuous input and output currents, which reduce the additional filtering elements usually required for interfacing dc/dc converter topologies. However, PV systems based on Cuk converters usually do not provide formal proofs of global stability under realistic conditions, which makes impossible to ensure a safe operation of the PV installation. Therefore, this paper proposes a high performance sliding-mode controller for PV systems based on Cuk converters, which regulates the PV voltage in agreement with the commands imposed by a MPPT algorithm, rejecting both load and environmental perturbations, and ensuring global stability for real operation conditions. Finally, the performance of the regulated PV system is tested using both simulations and experiments.


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