Hydro Photovoltaic Technology- A new approachRupal Jain
A brief description about hydro photovoltaic technology- PV panels on water bodies to improve their efficiency and to reduce water evaporation losses. A government scheme on this technology in Khandwa district MP state
engineers are encouraged to take up new initiative under my mentorship to learn new things and do something good for the world.pl do encourage young engineers from colleges and adopt them for better future.
The project we have undertaken is “Solar Inverter”. A solar inverter, or PV inverter, converts the direct current (DC) output of a photovoltaic solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-line electrical network.
A solar inverter, or PV inverter, converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a critical component in a photovoltaic system, allowing the use of ordinary commercial appliances. Solar inverters have special functions adapted for use with photovoltaic arrays, including maximum power point tracking and anti-islanding protection.
Hydro Photovoltaic Technology- A new approachRupal Jain
A brief description about hydro photovoltaic technology- PV panels on water bodies to improve their efficiency and to reduce water evaporation losses. A government scheme on this technology in Khandwa district MP state
engineers are encouraged to take up new initiative under my mentorship to learn new things and do something good for the world.pl do encourage young engineers from colleges and adopt them for better future.
The project we have undertaken is “Solar Inverter”. A solar inverter, or PV inverter, converts the direct current (DC) output of a photovoltaic solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-line electrical network.
A solar inverter, or PV inverter, converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a critical component in a photovoltaic system, allowing the use of ordinary commercial appliances. Solar inverters have special functions adapted for use with photovoltaic arrays, including maximum power point tracking and anti-islanding protection.
Electrical and Solar PV Systems (www.solartraining.ca)Irtaza M. Syed
Overview and basics of conventional electric power distribution and solar Photo-voltaic (PV) systems. Generation, Transmission, distribution and utilization. Power flow, anti-islanding and PV systems connection to utility. PV applications and market. (www.solartraining.ca)
Off grid solar power systems design is said to be complex. In this presentation, a simple design process is described: starting by load assessment, then moving to estimating array energy output; estimating array power and determining required number of modules as well as the size of other system components.
This presentation is adapted from a course delivered online by Mathy Mpassy Isinki. After ten years spent providing energy solutions in remote off grid locations, he describes himself as an off grid energy solutions business and technical sales professional; his goal is to share with you what he has learned the last ten years.
Як часто ви кажете «Поклади планшет – треба вчити уроки!»? Діти сприймають комп’ютер виключно як іграшку? Пропонуємо міняти ситуацію зацікавивши дитину творчим завданням.
Є прекрасне оповідання Сергія Носаня «День блакитної весни». В тексті згадується велика кількість рослин і важливо, щоб діти їх побачили, бо текст не несе в собі розповідь про події, а створює атмосферу пізнання. Прочитайте разом з дитиною оповідання і складіть презентацію про рослини та птахів, що згадуються в оповіданні. Діти разом з вами попрацюють з комп’ютером.
Поділіться враженнями від спільної творчості в коментарях на наших сторінках в соціальних мережах?
https://www.facebook.com/ocinochki
https://vk.com/ocinochki
Більше матеріалів на нашому сайті http://ocinochki.com.ua/
En 2015 : 15 000 € + 21j/homme
Objectif
- Permettre aux entreprises de trouver les ressources dont elles ont besoin.
- Développer les compétences et les talents,
- Favoriser l’adéquation entre la demande (étudiants, demandeurs d’emploi, reconversions) et l’offre de formation,
Axe d’action majeur issu des travaux du think tank numérique régional.
Electrical and Solar PV Systems (www.solartraining.ca)Irtaza M. Syed
Overview and basics of conventional electric power distribution and solar Photo-voltaic (PV) systems. Generation, Transmission, distribution and utilization. Power flow, anti-islanding and PV systems connection to utility. PV applications and market. (www.solartraining.ca)
Off grid solar power systems design is said to be complex. In this presentation, a simple design process is described: starting by load assessment, then moving to estimating array energy output; estimating array power and determining required number of modules as well as the size of other system components.
This presentation is adapted from a course delivered online by Mathy Mpassy Isinki. After ten years spent providing energy solutions in remote off grid locations, he describes himself as an off grid energy solutions business and technical sales professional; his goal is to share with you what he has learned the last ten years.
Як часто ви кажете «Поклади планшет – треба вчити уроки!»? Діти сприймають комп’ютер виключно як іграшку? Пропонуємо міняти ситуацію зацікавивши дитину творчим завданням.
Є прекрасне оповідання Сергія Носаня «День блакитної весни». В тексті згадується велика кількість рослин і важливо, щоб діти їх побачили, бо текст не несе в собі розповідь про події, а створює атмосферу пізнання. Прочитайте разом з дитиною оповідання і складіть презентацію про рослини та птахів, що згадуються в оповіданні. Діти разом з вами попрацюють з комп’ютером.
Поділіться враженнями від спільної творчості в коментарях на наших сторінках в соціальних мережах?
https://www.facebook.com/ocinochki
https://vk.com/ocinochki
Більше матеріалів на нашому сайті http://ocinochki.com.ua/
En 2015 : 15 000 € + 21j/homme
Objectif
- Permettre aux entreprises de trouver les ressources dont elles ont besoin.
- Développer les compétences et les talents,
- Favoriser l’adéquation entre la demande (étudiants, demandeurs d’emploi, reconversions) et l’offre de formation,
Axe d’action majeur issu des travaux du think tank numérique régional.
Axe 4 : Communication et visibilite - Frenchsouth.digitalFrenchsouth.digital
Donner une plus grande visibilité aux entreprises.
Pour l’ensemble des membres du FRENCHSOUTH.digital, mais également l’intégralité de la filière régionale du Numérique.
This project proposes a simplified PV module simulator with MPPT. The PV model is designed in Matlab/Simulink based on various mathematical equations. This paper explains the use of MPPT technique in a photovoltaic system. The MPPT is implemented by incremental conductance or perturbation and observation methods. The overall system is designed, developed and validated by using MATLAB/SIMULINK
Fuzzy Sliding Mode Control for Photovoltaic SystemIJPEDS-IAES
In this study, a fuzzy sliding mode control (FSMC) based maximum power point tracking strategy has been applied for photovoltaic (PV) system. The key idea of the proposed technique is to combine the performances of the fuzzy logic and the sliding mode control in order to improve the generated power for a given set of climatic conditions. Different from traditional sliding mode control, the developed FSMC integrates two parts. The first part uses a fuzzy logic controller with two inputs and 25 rules as an equivalent controller while the second part is designed for an online adjusting of the switching controller’s gain using a fuzzy tuner with one input and one output. Simulation results showed the effectiveness of the proposed approach achieving maximum power point. The fuzzy sliding mode (FSM) controller takes less time to track the maximum power point, reduced the oscillation around the operating point and also removed the chattering phenomena that could lead to decrease the efficiency of the photovoltaic system.
Improved strategy of an MPPT based on the sliding mode control for a PV system IJECEIAES
The energy produced using a photovoltaic (PV) is mainly dependent on weather factors such as temperature and solar radiation. Given the high cost and low yield of a PV system, it must operate at maximum power point (MPP), which varies according to changes in load and weather conditions. This contribution presents an improved maximum power point tracking (MPPT) controllers of a PV system in various climatic conditions. The first is a sliding mode MPPT that designed to be applied to a buck converter in order to achieve an optimal PV array output voltage. The second MPPT is based on the incremental conductance algorithm or Perturb-and-Observe algorithm. It provides the output reference PV voltage to the sliding mode controller acting on the duty cycle of the DC-DC converter. Simulation is carried out in SimPower toolbox of Matlab/Simulink. Simulation results confirm the effectiveness of the sliding mode control MPPT under the parameter variation environments and shown that the controllers meet its objectives.
A Novel Approach on Photovoltaic Technologies for Power Injection in Grid Usi...IJERA Editor
The paper presents the simulation of the Solar Photovoltaic module using Matlab Simulink. This model is based on mathematical equations and is described through an equivalent circuit including a photocurrent source, a diode, a series resistor and a shunt resistor. This paper presents integration of the grid distribution network in Indian scenario with solar power technology to meet the additional electrical energy demand of urban as well as rural sectors which are both rapidly expanding. First of all the data of a real life power plant having 24V, 230W Power PV module has been compared and analyzed with that of matlab program output for identical module and it has been find out that a variation in temperature affects the parameters values as well as the performance of the solar module. After the above analysis the design and Simulink implementation for single phase power grid connected PV system has been done. The system includes the PV array model, the integration of the MPPT with boost dc converter , dc to ac inverter, single phase series load connected to ac grid. It is demonstrated that the model works well at different temperature conditions and predicting the General behavior of single-phase grid- connected PV systems .
EFFECT OF HOT-SPOTTED CELL ON PV MODULE PERFORMANCEIAEME Publication
In this paper, the effects of the hot-spotted cell on PV module were evaluated. The
experimental observation was based on 100 kW PV array composed of 20 PV modules.
It was found that an increasing number of hot-spotted solar cells in a PV module would
likely increase its output power loss. It was also noticed that most of the PV modules
affected by hot-spotted PV string are relatively affected by high-temperature levels,
dust, and Partial shading due to trees or tall vegetation. Furthermore, the average
performance ratio (PR) and degradation rate (DR) of all examined PV modules were
analyzed. PR was observed to have a higher value of 0.78 in a non-hot-spotted PV array,
whereas low PR of 0.65 was observed in a hot-spotted PV array. High DR of 3.13/year
was observed in hot-spotted PV array; while low DR of 1.48/year was found in a module
with no hot-spot. It was evident that the mean PR is significantly reduced due to the
existence of hot-spots in the PV modules. DR was also increased due to hot-spot in the
PV array. Hence, it is important to select materials that have the highest thermal
stability to avoid mild hot spot situations that will lead to immediate damage of the
panel. Hot-spot study analysis will help increase PV lifetime power output by detecting
and preventing hot spotting before it permanently damages the PV panel.
Ijaems apr-2016-3 A Study of nature of the Photovoltaic modules under the inf...INFOGAIN PUBLICATION
The behaviour of the solar photovoltaic array will be rapidly changing under the influence of partial shading phenomenon. When two (or) more photovoltaic modules are embedded in series, then the total output voltage and the net output power obtained from the series connected photovoltaic modules will mainly depends upon the solar insolation which is being projected upon each and every module respectively. Small perturbation in solar irradiation levels will lead to large considerable change in the output parameters. This paper mainly focuses on observing the effect of partial shading on photovoltaic modules which are connected in series. The main objective of this paper is to examine about the mismatching phenomenon that occurs while tracking the global maxima point which plays a vital role in extracting maximum power from solar photovoltaic array in an effective manner.
Modeling and Simulation of Fuzzy Logic based Maximum Power Point Tracking (MP...IJECEIAES
This paper presents modeling and simulation of maximum power point tracking (MPPT) used in solar PV power systems. The Fuzzy logic algorithm is used to minimize the error between the actual power and the estimated maximum power. The simulation model was developed and tested to investigate the effectiveness of the proposed MPPT controller. MATLAB Simulink was employed for simulation studies. The proposed system was simulated and tested successfully on a photovoltaic solar panel model. The Fuzzy logic algorithm succesfully tracking the MPPs and performs precise control under rapidly changing atmospheric conditions. Simulation results indicate the feasibility and improved functionality of the system.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...Yayah Zakaria
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence,
multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...IJECEIAES
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence, multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
The purpose of this article is to extract the maximum power point at which the photovoltaic system can operate optimally. The system considered is simulated under different irradiations (between 200 W/m2 and 1000 W/m2), it mainly includes the established models of solar PV and MPPT module, a DC/DC boost converter and a DC/AC converter. The most common MPPT techniques that will be studied are: "Perturbation and Observation" (P&O) method, "Incremental Conductance" (INC) method, and "Fuzzy Logic" (FL) control. Simulation results obtained using MATLAB/Simulink are analyzed and compared to evaluate the performance of each of the three techniques.
MAXIMUM POWER POINT TRACKING ALGORITHMS APPLIED TO WIND-SOLAR HYBRID SYSTEMArunkumar Tulasi
Importance od PV system, Wind energy conversion system.Renewable energy is the energy which comes from natural resources such as sunlight, wind, rain,
tides and geothermal heat. These resources are renewable and can be naturally replenished.
Therefore, for all practical purposes, these resources can be considered to be inexhaustible,
unlike dwindling conventional fossil fuels [1]. The global energy crunch has provided a renewed
impetus to the growth and development of Clean and Renewable Energy sources. Clean
Development Mechanisms (CDMs) [2] are being adopted by organizations all across the globe.
Apart from the rapidly decreasing reserves of fossil fuels in the world, another major factor
working against fossil fuels is the pollution associated with their combustion. Contrastingly,
renewable energy sources are known to be much cleaner and produce energy without the harmful
effects of pollution unlike their conventional counterparts.
When the irradiance distribution over the photovoltaic panels is uniform, the pursuit of the maximum power point is not reached, which has allowed several researchers to use traditional MPPT techniques to solve this problem Among these techniques a PSO algorithm is used to have the maximum global power point (GMPPT) under partial shading. On the other hand, this one is not reliable vis-à-vis the pursuit of the MPPT. Therefore, in this paper we have treated another technique based on a new modified PSO algorithm so that the power can reach its maximum point. The PSO algorithm is based on the heuristic method which guarantees not only the obtaining of MPPT but also the simplicity of control and less expensive of the system. The results are obtained using MATLAB show that the proposed modified PSO algorithm performs better than conventional PSO and is robust to different partial shading models.
Modeling and Simulation of Solar Photovoltaic module using Matlab/SimulinkIOSR Journals
Abstract: This paper presents the circuit model of photovoltaic (PV) module. Simulation and modeling is done
using MATLAB/ Simulink software package. The proposed model is user friendly and can be used as a common
platform for both applied physics scientist and power electronics engineers. A detailed modeling procedure is
presented. The designed model is verified by using STP255-20/Wd PV module. The IV and PV characteristics
are simulated at different temperature and irradiance conditions and the results are verified. The proposed
model is very simple fast and accurate. The designed model can be used for analysis of PV characteristics and
for simulation of maximum power point tracking algorithms
Eternal Sun Group - Bifacial measurements, towards a new norm!Marcello Passaro
ITRPV and customers feedback show that there is a shift towards bifacial modules, however a concern on how to correctly test bifacial modules. Eternal Sun Group has together with research and development institutes like ECN looked at the complications and implications hereof.
In photovoltaic (PV) systems, maximum power point tracking (MPPT) techniques are used to track the maximum power from the PV array under the change in irradiance and temperature conditions. The perturb and observe (P&O) is one of the most widely used MPPT techniques in recent times due to its simple implementation and improved performance. However, the P&O has limitations such as oscillation around the MPP during which time the P&O algorithm will become confused due to rapidly changing atmospheric conditions. To overcome the above limitation, this paper uses the fuzzy logic controller (FLC) to track the maximum power from the PV system under different irradiance, integrates it with a DC-DC boost converter as a tracker. The result of the FLC performance is compared with the traditional P&O method and shows the MPPT algorithm based on FLC ensures continuous tracking of the maximum power within a short period compared with the traditional P&O method. Besides that, the proposed method (FLC) has a faster dynamic response and low oscillations at the operating point around the MPP under steady-state conditions and dynamic change in irradiance.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Generating a custom Ruby SDK for your web service or Rails API using Smithyg2nightmarescribd
Have you ever wanted a Ruby client API to communicate with your web service? Smithy is a protocol-agnostic language for defining services and SDKs. Smithy Ruby is an implementation of Smithy that generates a Ruby SDK using a Smithy model. In this talk, we will explore Smithy and Smithy Ruby to learn how to generate custom feature-rich SDKs that can communicate with any web service, such as a Rails JSON API.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Neuro-symbolic is not enough, we need neuro-*semantic*
C05410915
1. IOSR Journal of Engineering (IOSRJEN) www.iosrjen.org
ISSN (e): 2250-3021, ISSN (p): 2278-8719
Vol. 05, Issue 04 (April. 2015), ||V1|| PP 09-15
International organization of Scientific Research 9 | P a g e
The influence of temperature of photovoltaic modules on
performance of solar power plant
Modestas Pikutis1
, Dominykas Vasarevičius2
, Romanas Martavičius3
1(
PhD student, Department Of Electronic System, Vilnius Gediminas Technical University, Vilnius, Lithuania)
2
(PhD, Department Of Electronic System, Vilnius Gediminas Technical University, Vilnius, Lithuania)
3
(Professor, Department Of Electronic System, Vilnius Gediminas Technical University, Vilnius, Lithuania )
Abstract: - Studies and research of photovoltaic power plants in real world conditions with a goal to find more
effective control algorithms require significant investment in equipment and takes a lot of time. To accelerate the
research, mathematical models are designed, which allow to simulate processes in photovoltaic power plant
under conditions close to the real ones. To investigate the effects of temperature variations, the block of
temperature is designed, which allows imitating the processes lasting for month or even several years. This
block is used in a model of photovoltaic power plant, developed in earlier studies. The model described in this
paper consists of four structural blocks: a block, imitating the solar energy flux; the block, for simulation of
temperature variations; the block, imitating photovoltaic module and the control algorithm, in which the
maximum power point tracking is performed using IncCond algorithm. The model of photovoltaic power plant is
implemented in Matlab/Simulink environment. The model is used to investigate the effects of photovoltaic
module temperature on performance of the power plant during a cloudy day. It is proved, that due to overheated
photovoltaic modules the efficiency of power plant is decreased. It is proved, that it is possible to increase the
efficiency of photovoltaic power plant from 11 % to 31 % applying forced cooling to all of the photovoltaic
modules.
Keywords: temperature of photovoltaic cell, maximum power point tracking, shadows.
I. INTRODUCTION
Many researches are conducted with a goal to improve physical properties of photovoltaic (PV) cells.
The efficiency of the most of PV cells is less than 20 %. Since the efficiency of PV cells is small, it is important,
that they always operate at maximum power point (MPP). To maintain such operational conditions, special
controllers, implementing different maximum power point tracking (MPPT) algorithms are used [1], [2]. The
selected control algorithm influences how quickly MPP of the PV module will be found and how precisely it
will be tracked.
MPP tracking in solar power plant is complicated because of unpredictably varying environmental
conditions and different characteristics of different PV cells or modules. These differences can appear on some
of the PV models of a single power plant if it affected be partial shadow, snow cover, hoarfrost, dust or tree
leaves stuck on the surface of some PV modules. These effects are of random nature and it is impossible to
predict their influence for different PV modules. Because of these effects it is not possible to predict the correct
load of solar power plant at certain time intervals.
It is very important to keep the correct loading of PV modules, because only in this case the solar
power plant will operate at MPP and will utilize the available solar power flux (SPF) with highest efficiency.
The position of MPP in current-voltage characteristics of PV module can vary because of temperature
[3]. Earlier simulations were performed, assuming, that the temperature is 25°C and is constant. MPPT
algorithms were investigated only depending on variations of SPF. However, in order to accurately assess and
investigate the operation of solar power plant under conditions, close to real world, it is important assess the
influence of variations of PV module temperature.
Studies and research of solar power plants in real world conditions require significant investment in
equipment and takes a lot of time. This can be avoided by investigating the developed mathematical model of
solar power plant and simulating real world conditions. This allows to compare the operation of solar power
plant at certain time intervals, when only preferred parameters are changed.
2. The influence of temperature of photovoltaic modules on performance of solar power plant
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In this work, the influence of temperature performance of separate PV modules and whole solar power
plant is investigated. To achieve this, the Matlab/Simulink model, developed in previous works is used [4]. A
block, imitating temperature variations at defined time interval is added.
II. INFLUENCE OF TEMPERATURE TO THE PERFORMANCE OF
PHOTOVOLTAIC MODULE
From previous studies it is known that the power plant controller is particularly sensitive to rapid
changes of SPF. However, it is not known how the controller responds when to main factors, influencing it`s
operation are varying simultaneously – changing SPF and module temperature [5]. The operation of the solar
power plant is studied in the following order: firstly the impact of environmental conditions on one PV model is
studied, then on solar power plant, consisting of four PV modules.
Figure 1 MPP at different SPF and temperatures [6]
Varying SPF, falling to the surface of PV module is simulated, when module temperature grows from
25°C to 50°C. Simulated current-voltage characteristics are presented in Fig. 1. The first series show the
location of MPP, when PV module temperature is 25°C and it is illuminated by SPF equal to 1000 W/m2
. The
second series show the location of MPP, when PV module is illuminated by SPF equal to 600 W/m2
while the
temperature is the same 25°C. The third series show MPP when SPF is only 400 W/m2
and the temperature is
still the same 25°C. These series characterize the location of MPP at the same temperature and different SPF.
The fourth and fifth curves show the influence of temperature rise from 25°C to 50°C on the location of MPP.
Comparing first, second and third series reveals, that at constant temperature, the decrement of SPF
causes significant decrement of PV modules output current. The decrement of SPF from 1000 W/m2
to
600 W/m2
causes the decrement of current by 1.9 A and voltage by 1.1 V. Thus power decreases by 32.7 W
(series 1 and 2). When the temperature of the PV module is 50°C and SPF falls from 800 W/m2
to 600 W/m2
–
the current decreases by 0.97 A and voltage –by 0.6 V (series 4 and 5). This causes the decrement of power by
14.2 W. When SPF is at constant level of 600 W/m2
and temperature rises from 25°C to 50°C, the output current
of PV module remains almost unchanged, but the voltage decreases by 2.3 V, so the power decreases by 9 W
(series 2 and 4).
According to series 2 and 4 it is seen, that when the SPF is 600 W/m2
, the output power of PV module
is higher at lower temperature. Analysis of the model proves that the increment of PV modules temperature
decreases its efficiency, so less power is available at the output of the model at the same SPF. It can be stated
that the characteristics of operation of PV module depend not only on SPF, but also on module temperature and
it is necessary to keep it as low as possible.
III. STRUCTURAL DIAGRAM OF A MODEL
In Fig. 2 the structural diagram of solar power plant, for evaluation of temperature effects on
performance is presented. In this model, the power plant can consist of the required number of PV modules.
Each PV module consists of 28 PV cells. The overall power of the PV module at standard test conditions is
78 W. For this experiment four modules are being used so the total power of the solar power plant is 300 W.
Similar signal ST, imitating SPF is sent to each PV module. It is generated by SPF block. The parameters of
this block are selected in such a way, that it imitates SPF signal, close to the real one on a partially cloudy day.
3. The influence of temperature of photovoltaic modules on performance of solar power plant
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To simulate the effects of temperature to the performance of the solar power plant, the temperature simulation
block is used. In the model it is assumed, that all the modules are of the same type, and they are affected with
the same solar radiation, so the same temperature signal is used for all the modules. Thus, these blocks simulate
SPF and instantaneous temperature of the modules [4],[7].
Figure 2 Structural diagram of a mathematical model
PV modules affected by SPF and temperature output voltage UFVM and the current IFVM, which
flows through the load. In the analyzed solar power plant MPPT is performed according to IncCond algorithm
[2]. According to the algorithm, PV modules output power derivative with respect to voltage dP/dU is
calculated. The result describes the position of systems operation point in the power characteristic in relation
with MPP. According to the results, the load resistance is increased or decreased by step ΔR1.
IV. MATHEMATICAL MODEL OF SOLAR POWER PLANT
To investigate the influence of temperature variations on performance of solar power plant, according
to described structural diagram (Fig. 2) the mathematical model is developed in Matlab/Simulink environment
(Fig. 3). The core of the model is block, imitating SPF signal. This block has the following inputs: inclination
angle, albedo, day of the year, longitude and time zone. These parameters can be adapted to simulate SPF falling
to the inclined surface in any location on Earth at any time.
The model also includes the block to simulate cloud cover. This block attenuates the SPF signal and
imitates additional diffused and reflected components of solar radiation. After applying Gaussian filter, the SPF
signal, imitating real world conditions is formed [8].
The generated SPF signal imitates sunrise at 6:00 o’clock and sunset – 21:00 o’clock. Thus tem
maximum power point tracking in solar power plant continues for 15 hours – the whole daylight time. The
similar SPF signal falls to all four PV modules of the solar power plant.
The temperature of PV modules is defined in temperature simulation block, which sends generated
signal to all PV modules. This block sets the temperature of PV modules depending on intensity of solar
radiation and wind speed [9]. The goal of research is to determine the influence of temperature variation of PV
modules on performance of solar power plant, when temperature changes rather fast (high wind speed) and slow
(low wind speed).
4. The influence of temperature of photovoltaic modules on performance of solar power plant
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Figure 3 Matlab/Simulink model with temperature block
V. PLANT INCCOND ALGORITHM
In this work, IncCond algorithm is selected to perform maximum power point tracking [10]. This
algorithm has simple control structure and is able to keep the system in MPP, when it is found. Simple
mathematical implementation of algorithm allows achieving fast operation on the equipment with limited
hardware resources such as embedded systems. The flowchart of IncCond algorithm is presented in Fig. 4.
The MPPT algorithm implemented in the model allows fast and precise finding of MPP and has the
ability to keep the system in MPP, until the environmental conditions will change. Most of other algorithms are
not able to precisely track MPP, and the system oscillates around it.
Figure 4 The flowchart of IncCond algorithm, implemented in the model of solar power plant
MPPT is performed by calculating the power derivative with respect to voltage.
( )dP d IV dI
I V
dV dV dV
(1)
5. The influence of temperature of photovoltaic modules on performance of solar power plant
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Expression (1) allows to calculate the derivative in voltage-current characteristics and to determine the
direction of change in load resistance. According to Fig 3 the load resistance changes can be described by these
conditions:
, ,
, ,
, ,
dI I
R = R + Rl ldV V
dI I
R = R Rl ldV V
dI I
R RmldV V
(2)
where, ΔR – step of load resistance change, Rl – load resistance for PV modules, Rm characteristic load
resistance, at which the PV module is operating with maximum power output.
The solar power plant operates at MPP when the third condition of expression (2) is satisfied.
VI. INFLUENCE OF TEMPERATURE ON PERFORMANCE OF SOLAR
POWER PLANTS
A conclusion section must be included and should indicate clearly the advantages, limitations, and
possible applications of the paper. Although a conclusion may review the main points of the paper, do not
replicate the abstract as the conclusion. A conclusion might elaborate on the importance of the work or suggest
applications and extensions.
Figure 5 Solar power flux (a), temperature of PV modules during a slightly windy day without
forced cooling (b-1), temperature of PV modules during a slightly windy day with forced cooling to 18°C
(b-2), instantaneous power of solar power plant without forced cooling (c-3), instantaneous power of solar
power plant with forced cooling to 18°C (c-4), instantaneous difference of output power (d).
In this work different environmental conditions were simulated in separate tests. First test assumed
slow rate of change of temperature of PV modules, which sometimes rise to 75°C. This scenario is common for
a clear day with small wind speed. Increasing the SPF causes the rise of PV modules temperature. The SPF
chart, shown in fig. 6 a) imitates daylight time, when SPF varies from 0 to 1000 W/m2
. In fig 6 b) the first series
show the variation of PV modules temperature during day. The second series show the temperature of PV
modules when the forced cooling is engaged. Forced cooling is enabled when temperature reaches 18°C. In fig 6
c) series 3 show the instantaneous power at the output of solar power plant, when the forced cooling is not used
and series 4 – when the temperature of PV modules is cooled to 18°C or lower. Fig 6 d) shows the instantaneous
difference in power when the PV modules are not cooled and with forced cooling.
6. The influence of temperature of photovoltaic modules on performance of solar power plant
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When the temperature of PV modules is dependent on environmental conditions, the solar power plant
during a daylight time produces 1558 Wh of energy. During the same period of time and under the same
environmental conditions, the solar power plant with forcibly cooled modules produces 2051 Wh of electrical
energy.
The second test assumes the faster rate of change of PV modules temperature and it sometimes rises to
50°C. This pattern is typical for a day with a gusty wind. Strong wind causes faster cooling of PV modules, so
their temperature cannot rise significantly. Fig. 7 a) shows SPF signal, which is similar to the previous test. In
fig. 7 series 1 shows the dependence of PV modules temperature in dependence on SPF and series 2 shows the
temperature of PV modules, when the forced cooling is used. In fig. 7 c) series 3 show instantaneous output
power when PV modules are not cooled and series 4 – when forced cooling is used. Same as in previous test the
comparison of output power between cooled and not cooled system is provided (Fig. 7 d)).
Figure 6 Solar power flux (a), temperature of PV modules during windy day without forced cooling (b-1),
temperature of PV modules during windy day with forced cooling to 18°C (b-2), instantaneous power of
solar power plant without forced cooling (c-3), instantaneous power of solar power plant with forced
cooling to 18°C (c-4), instantaneous difference of output power (d).
When wind is gusty, the temperature of PV modules changes rapidly, and it does not rise significantly.
During the 15 hours of daytime the power plant produces 1822 Wh of electrical energy. In case of forced
cooling, when the temperature of PV modules is kept not higher than 18°C, the solar power plant produces 2029
Wh of electrical energy during the same period of time.
This study show that during the 15 hours of daylight, the amount of energy, produced in the solar
power plant was by 264 Wh smaller when the temperature of PV modules changed slowly and reached 75°C.
When the forced cooling of PV modules is used during a day with small wind speeds, the energy production of
solar power plant increases by 492 Wh, and in case of a day with strong, gusty wing, the energy increment is
207 Wh.
VII. CONCLUSION
The efficiency of PV module decreases when its temperature increases. Studies have shown:
1. The efficiency of solar power plant can be significantly increased by applying the forced cooling of PV
modules, especially, when solar power plant is installed in the location with small wind speeds.
2. Applying a forced cooling to PV modules and keeping their temperature not higher than 18°C, during a day
with small wind speed, the electrical energy output of solar power plant increases by 31.5 %, compared to
the case, when cooling is not used.
3. Applying a forced cooling to PV modules and keeping their temperature not higher than 18°C, during a day
with strong, gusty wind, the electrical energy output of solar power plant increases by 11.3 %, compared to
the case, when cooling is not used.
7. The influence of temperature of photovoltaic modules on performance of solar power plant
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