Current technology used in On-Grid PV systems has many drawbacks. The purpose of this paper is to discuss and categorize the problems and drawbacks inherent in residential and commercial photovoltaic systems.
Typical residential photovoltaic installations suffer from numerous problems that prevent this technology from realizing its full market potential. Many of the present problems stem from
power losses – whether due to module mismatch, orientation mismatch, or partial shading. Other
problems stem from system design limitations and constraints, lack of monitoring and lack of analysis
abilities. In addition, the absence of safety features poses risks to both workers installing or maintaining
the system, and to firefighters dealing with fires in the vicinity of PV installations.
Avnet Electronics Marketing ushers in the summer solstice with a white paper detailing the Fundamentals of Photovoltaic Solar Technology for Battery Powered Applications. Find more solar applications from Avnet at www.em.avnet.com/solar
J Lanka - SolarEdge provides next generation solar power harvesting and monitoring solutions that effectively remove all known system constraints across the photovoltaic energy space. Our Smart DC ASIC technology and active electronics enable increased production of clean, grid-ready energy at a lower cost.
Traditional photovoltaic installations suffer from a broad range of limitations that prevent them from reaching their full potential. Module mismatch and partial shading prevent systems from achieving their optimum. System design is made complex due to numerous constraints, such as the inability to leverage full roof real estate, to combine strings of different lengths, or to easily address differing roof facets. Traditional systems lack monitoring and analysis capabilities, as well as critical safety features. The systems can pose risks to workers installing or maintaining the system, as well as to firefighters dealing with fires in the vicinity of a PV installation.
development and experimental validation of a global simulation model of an high power electrical drive (Ansaldo Sistemi Industiali) in a cement plant (Italcementi)
Avnet Electronics Marketing ushers in the summer solstice with a white paper detailing the Fundamentals of Photovoltaic Solar Technology for Battery Powered Applications. Find more solar applications from Avnet at www.em.avnet.com/solar
J Lanka - SolarEdge provides next generation solar power harvesting and monitoring solutions that effectively remove all known system constraints across the photovoltaic energy space. Our Smart DC ASIC technology and active electronics enable increased production of clean, grid-ready energy at a lower cost.
Traditional photovoltaic installations suffer from a broad range of limitations that prevent them from reaching their full potential. Module mismatch and partial shading prevent systems from achieving their optimum. System design is made complex due to numerous constraints, such as the inability to leverage full roof real estate, to combine strings of different lengths, or to easily address differing roof facets. Traditional systems lack monitoring and analysis capabilities, as well as critical safety features. The systems can pose risks to workers installing or maintaining the system, as well as to firefighters dealing with fires in the vicinity of a PV installation.
development and experimental validation of a global simulation model of an high power electrical drive (Ansaldo Sistemi Industiali) in a cement plant (Italcementi)
This paper investigates the performances of different photovoltaic (PV) array under several shading condition. Four types of photovoltaic array configuration scheme which are ‘Series’ (S), Series-Parallel’ (SP), Total-Cross-Tied’ (TCT), and ‘Bridge-Link’ (BL) array topologies were tested by applying a 6x6 PV array under 6 different shading scenarios. The modeling is developed using Matlab/Simulink. The performances and output characteristics of photovoltaic array are compared and analyzed. System engineer can use the detailed characteristics of different array configuration to approximate the outcome power and pick the best configuration of the system by concerning the current natural condition to enhance the overall efficiency.
This paper presents a novel simplied PWM technique to drive switched capacitor type multi-level inverter fed from isolated type DC-DC converter for distributed generation. Distributed generation (DG) is renowned power generation at point of utility with no environmental aects and reduces transmission line losses. Photo-voltaic system is considered as renewable energy source for DG and the low voltage from PV system is boosted to required voltage using an isolated type single-input multi-output (SIMO) DC-DC converter. DC output from isolated SIMO DC-DC converter is fed to switched capacitor type multi-level inverter (SC-MLI) to feed the AC load. Isolated SIMO DC-DC converter apart from boosting the DG output voltage, also eliminates the problem of voltage unbalancing in SC-MLI topology. Closed loop operation of SIMO DC-DC converter employs only single PI controller instead of three controllers was presented in this paper. Modes of operation of SC-MLI and Novel PWM switching pattern was explained. Simulation of proposed system was developed using MATLAB/SIMULINK software. The prototype was developed for the proposed system and hardware results are also shown.
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic GeneratorsIJPEDS-IAES
Considering the optimization of a photovoltaic system, several studies show the advantage in the choice of a distributed structure. For such structures small power converters such as the boosts and buck converters appear as most appropriate. We have analysed the efficiency of small power boost- converters especially dedicated for photovoltaic energy conversion systems working in the middle and high voltage ranges. The setup studied is a photovoltaic generator connected to an AC grid working in 230 Volts via an inverter. Moreover, we considered the possibility of multiple electrical energy sources as photovoltaic, wind systems in the same energy production system, which obliged an adaptive converter structure. We evaluated the losses in the various stages of a boost converter and point out the importance of the power MOSFET used as the commutation element. New transistors databases obtained from manufacturers show the nonlinear dependency between the resistance drain-source when passing, Rdson and the maximum rating voltage when the transistor is off, Vdsmax, for all transistor families. Thus nonlinear dependency induces a huge increase of losses with the voltage in the MOSFET, and as a direct consequence in the converter the more as Vdsmax is higher. In order to minimize losses of the converter we have designed and realized a new high efficiency version of a Step-Up structure based on a commutation element integrating a low Vdsmax voltage MOSFET and very low Rdson.
In this paper a buck-boost dc-dc converter for pv application is proposed, which is mainly composed of a buck – boost converter, PV panel, load and a battery. Existing dc-dc converter can convert the power from the PV panel, but unfortunately the PV panel can only provide power when there is a high intensity of light. In order to provide power supply to the load without any interruption, buck-boost dc-dc converter is introduced. The power intermittency issue of PV panel can be overcome with the aid of a secondary supply which is in this case, the batter. The integration system between the primary and the secondary supply is controlled by a simple proposed control scheme. Battery act as a power in the low voltage side while PV panel is taking over in the high voltage side. Buck-boost converter is operated either is buck or boost mode according to the performance of the PV panel. This paper is presented the simple control scheme to decide the mode suitable for the buck and boost mode. Various conditions are simulated to verify the working operation of the buck-boost converter and to representing solar panel in real life. Simulation and experimental are carried out to verify the system.
Dynamic solar powered robot using dc dc sepic topologyeSAT Journals
Abstract This paper provides an idea to maintain constant voltage to the charging battery at both low and high level light intensity by using SEPIC topology in solar powered robot. Here two batteries are used, one is for charging and another is for discharging. When battery 1 get charged in mean time the battery 2 which is already charged is used to run the robot, Switching will be controlled by ARM processor using DPDT relay, and also voltage and current levels are monitored. Maximum Power Point tracking of solar will be done by single axis tracking system. Keywords: Battery system, Solar MPPT, Robot model, SEPIC topology
Performance of Photovoltaic Assisted Five Level Diode Clamped Inverter fed In...IJMTST Journal
This paper presents the simulation and analysis of Photovoltaic assisted three phase five level Diode Clamped multilevel inverter fed induction motor drive. Photovoltaic technology is one of the most promising for distributed low power generation. Its ability to produce power by directly converting solar energy has led to tremendous surge in its demand. The Photovoltaic output DC is fed to the boost converter to step up the voltage. The use of multilevel inverters have become popular in recent years for high power applications and an effective and practical solution for increasing power and reducing harmonics of AC waveforms. So, here a five level multilevel inverter is used for generating AC voltage from five levels of DC voltages and enhance the performance of the system. The proposed system is used to reduce the amplitudes of all harmonics at the output of the inverter. The power quality improves by reducing the harmonics level. The simulation results for the proposed system are verified using Mat lab / Simulink. The TOTAL HARMONIC DISTORTION (THD) for Diode Clamped multi-level inverter is compared with the three phase inverter and it can be observed that in the higher levels the THD is reduced.
This paper investigates the performances of different photovoltaic (PV) array under several shading condition. Four types of photovoltaic array configuration scheme which are ‘Series’ (S), Series-Parallel’ (SP), Total-Cross-Tied’ (TCT), and ‘Bridge-Link’ (BL) array topologies were tested by applying a 6x6 PV array under 6 different shading scenarios. The modeling is developed using Matlab/Simulink. The performances and output characteristics of photovoltaic array are compared and analyzed. System engineer can use the detailed characteristics of different array configuration to approximate the outcome power and pick the best configuration of the system by concerning the current natural condition to enhance the overall efficiency.
This paper presents a novel simplied PWM technique to drive switched capacitor type multi-level inverter fed from isolated type DC-DC converter for distributed generation. Distributed generation (DG) is renowned power generation at point of utility with no environmental aects and reduces transmission line losses. Photo-voltaic system is considered as renewable energy source for DG and the low voltage from PV system is boosted to required voltage using an isolated type single-input multi-output (SIMO) DC-DC converter. DC output from isolated SIMO DC-DC converter is fed to switched capacitor type multi-level inverter (SC-MLI) to feed the AC load. Isolated SIMO DC-DC converter apart from boosting the DG output voltage, also eliminates the problem of voltage unbalancing in SC-MLI topology. Closed loop operation of SIMO DC-DC converter employs only single PI controller instead of three controllers was presented in this paper. Modes of operation of SC-MLI and Novel PWM switching pattern was explained. Simulation of proposed system was developed using MATLAB/SIMULINK software. The prototype was developed for the proposed system and hardware results are also shown.
Basic MOSFET Based vs Couple-Coils Boost Converters for Photovoltaic GeneratorsIJPEDS-IAES
Considering the optimization of a photovoltaic system, several studies show the advantage in the choice of a distributed structure. For such structures small power converters such as the boosts and buck converters appear as most appropriate. We have analysed the efficiency of small power boost- converters especially dedicated for photovoltaic energy conversion systems working in the middle and high voltage ranges. The setup studied is a photovoltaic generator connected to an AC grid working in 230 Volts via an inverter. Moreover, we considered the possibility of multiple electrical energy sources as photovoltaic, wind systems in the same energy production system, which obliged an adaptive converter structure. We evaluated the losses in the various stages of a boost converter and point out the importance of the power MOSFET used as the commutation element. New transistors databases obtained from manufacturers show the nonlinear dependency between the resistance drain-source when passing, Rdson and the maximum rating voltage when the transistor is off, Vdsmax, for all transistor families. Thus nonlinear dependency induces a huge increase of losses with the voltage in the MOSFET, and as a direct consequence in the converter the more as Vdsmax is higher. In order to minimize losses of the converter we have designed and realized a new high efficiency version of a Step-Up structure based on a commutation element integrating a low Vdsmax voltage MOSFET and very low Rdson.
In this paper a buck-boost dc-dc converter for pv application is proposed, which is mainly composed of a buck – boost converter, PV panel, load and a battery. Existing dc-dc converter can convert the power from the PV panel, but unfortunately the PV panel can only provide power when there is a high intensity of light. In order to provide power supply to the load without any interruption, buck-boost dc-dc converter is introduced. The power intermittency issue of PV panel can be overcome with the aid of a secondary supply which is in this case, the batter. The integration system between the primary and the secondary supply is controlled by a simple proposed control scheme. Battery act as a power in the low voltage side while PV panel is taking over in the high voltage side. Buck-boost converter is operated either is buck or boost mode according to the performance of the PV panel. This paper is presented the simple control scheme to decide the mode suitable for the buck and boost mode. Various conditions are simulated to verify the working operation of the buck-boost converter and to representing solar panel in real life. Simulation and experimental are carried out to verify the system.
Dynamic solar powered robot using dc dc sepic topologyeSAT Journals
Abstract This paper provides an idea to maintain constant voltage to the charging battery at both low and high level light intensity by using SEPIC topology in solar powered robot. Here two batteries are used, one is for charging and another is for discharging. When battery 1 get charged in mean time the battery 2 which is already charged is used to run the robot, Switching will be controlled by ARM processor using DPDT relay, and also voltage and current levels are monitored. Maximum Power Point tracking of solar will be done by single axis tracking system. Keywords: Battery system, Solar MPPT, Robot model, SEPIC topology
Performance of Photovoltaic Assisted Five Level Diode Clamped Inverter fed In...IJMTST Journal
This paper presents the simulation and analysis of Photovoltaic assisted three phase five level Diode Clamped multilevel inverter fed induction motor drive. Photovoltaic technology is one of the most promising for distributed low power generation. Its ability to produce power by directly converting solar energy has led to tremendous surge in its demand. The Photovoltaic output DC is fed to the boost converter to step up the voltage. The use of multilevel inverters have become popular in recent years for high power applications and an effective and practical solution for increasing power and reducing harmonics of AC waveforms. So, here a five level multilevel inverter is used for generating AC voltage from five levels of DC voltages and enhance the performance of the system. The proposed system is used to reduce the amplitudes of all harmonics at the output of the inverter. The power quality improves by reducing the harmonics level. The simulation results for the proposed system are verified using Mat lab / Simulink. The TOTAL HARMONIC DISTORTION (THD) for Diode Clamped multi-level inverter is compared with the three phase inverter and it can be observed that in the higher levels the THD is reduced.
Paul Farmer,
Chief Executive, Mind
Paul Farmer has been Chief Executive of Mind since 2006 and is currently the Chair of the Charities Consortium and leads the NHS England Mental Health Patient Safety Board. Previously, he has worked for Rethink Mental Illness and Samaritans.
Mr Farmer was praised by his charity sector peers when he was voted most admired charity chief executive at the Third Sector Most Admired Charities Awards 2013. He also received an Honorary Doctorate from the University of East London in recognition of his promotion of the understanding and support of mental health.
In June 2013, Mind released a review into the use of restraint in mental health settings and it has been instrumental in highlighting the issues to policy makers.
Presentation Topic: Listening to experience, reduce restraint
Dave Atkinson
Lead on Department of Health’s Positive and Safe Guidance
Independent Consultant Nurse working who led on Department of Health's ' 'Positive and Proactive Care'
It is a well-known fact that modules interfere negatively with each other in a serial connection; while the modules’ peak operating points are diverse, traditional inverters use a ‘one-size-fits-all’ approach to harvest their energy. Partial shading, or uneven exposure to sunlight, diversifies the modules even further as some can produce more than others now.
Organization of the Power Sector
Main expectations from the Sri Lanka Electricity Act 2009 as related to tariff
Corner stones in the Sri Lanka Electricity Act for Tariff Determination
Prerequisites for Tariff Determination in the legislation
Filing of Licensee Revenue Requirements
Generation Revenue Requirements
Transmission Revenue Requirements
Distribution Revenue Requirements
A summary of CEB Operational Costs
Simulation of incremental conductance mppt with direct control method using c...eSAT Journals
Abstract PV Module Maximum Power Point Tracker (MPPT) is a photovoltaic system that uses the photovoltaic array as a source of electrical power supply. Every photovoltaic (PV) array has an optimum operating point, called the maximum power point, which varies depending on cell temperature, the insulation level and array voltage. The function of MPPT is needed to operate the PV array at its maximum power point. The design of a Maximum Peak Power Tracking (MPPT) is proposed utilizing a cuk converter topology. Solar panel voltage and current are continuously monitored by a MPPT, and the duty cycle of the cuk converter continuously adjusted to extract maximum power. The design consists of a PV array, DC-DC cuk converter and many such algorithms have been proposed. However, one particular algorithm, the Incremental Conductance method, claimed by many in the literature to be inferior to others, continues to be by far the most widely used method in commercial PV MPPT’s. The general model was implemented on Mat lab, and accepts irradiance and temperature as variable parameters and outputs the I-V characteristic and P-V characteristic Index Terms: PV system; Maximum power point tracking (MPPT); Incremental conductance (Inccond); digital signal processor (dsp)
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Simulation of a 13-Level Inverter with Facts Capability for Distributed Energ...IJMTST Journal
This Paper Presents A whole New resonant twin active bridge(DAB) topology, that uses a tuned inductor-capacitor-inductor(LCL) network. As compared to ancient DAB topologies, the planned topologies significantly reduced the bridge current, lowering every physical phenomenon and alter losses and conjointly VA rating associated with the bridges. The performance of the DAB is investigated using a mathematical model at a lower place varied operational conditions. Experiment results of a model is reduced the outflow current of the circuit. are presented with discussion to demonstrate the improved performance of the LCL DAB topology. Result clearly that the planned DAB Topology provide higher efficiency over an oversized vary of every input voltage and as compared to ancient DAB topology
A SIMSCAPE based design of a dual maximum power point tracker of a stand-alon...IJECEIAES
This paper presents the simulation of a dual maximum power point tracker (dual-MPPT) and attempt to get the global maximum power point GMPP under partial shading conditions for a solar photovoltaic module using MATLAB SIMSCAPE. Traditional single MPP trackers are less efficient than dual MPP trackers and have greater sensitivity to partial shading. By using dual MPP trackers, one can get several features such as the possibility of connecting two arrays with different string sizes or different solar azimuths or tilts within high efficiency. This paper focuses on making the photovoltaic system work at maximum possible power under partial shading condition by using dual MPP trackers to achieve the convergence toward the global maximum power point GMPP.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed
The SolarEdge system outperforms SMA inverter and Enphase microinverter systems, in a standardized National Renewable Energy Laboratory (NREL) shading study conducted by PV Evolutions Lab (PVEL). This study simulates partial shading scenarios of typical residential rooftop photovoltaic (PV) systems, and evaluates the impact of different power conversion topologies on system performance.
The SolarEdge system harvests 1.9%, 5.0% and 8.4% more energy than SMA string inverter system with light, medium and heavy shading, respectively. The SolarEdge system produces more energy than Enphase microinverter system as well.
The test also determines a Shading Mitigation Factor (SMF) which represents the annual energy recovery of a power optimizer or microinverter system, compared to a traditional string inverter. The study found that the SolarEdge system recovered 28.3%, 21.9%, and 24.3% of energy lost by the string inverter system, with light, medium and heavy shading, respectively. These results indicate higher SMF results than even the Enphase microinverter system.
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.
SolarEdge technology Optimizing at the Module Level Get more power, more revenue, and more insight into your system performance.
Get professional advice on SolarEdge Residential and Commercial Solar PV Systems : http://goo.gl/dQBCyl
This powerpoint presentation is produced by IPCC Working Group I for outreach purposes. It is based on the figures and approved text from the Working Group I Summary for Policymakers with some additional information on the process. The IPCC Working Group I website www.climatechange2013.org provides comprehensive access to all products generated by Working Group I during the fifth assessment cycle of the IPCC.
IPCC Working Group II Contribution to AR5
The Working Group II contribution to the Fifth Assessment Report considers the vulnerability and exposure of human and natural systems, the observed impacts and future risks of climate change, and the potential for and limits to adaptation. The chapters of the report assess risks and opportunities for societies, economies, and ecosystems around the world.
The WGII AR5 Summary for Policymakers was approved at the 10th Session of Working Group II, held in Yokohama, Japan, from 25 to 29 March 2014. The Session also accepted the underlying scientific and technical assessment.
Original source : http://ipcc-wg2.gov/AR5/
Connecting SolarEdge power optimizers to solar PV panels makes them SMART PANELS that produce MORE POWER at all times.
SolarEdge is the proven leader in PV power optimisation with over 2 million
power optimisers installed in over 45 countries worldwide. The power optimizers connected to the panels enable them to produce more energy from your system, compared to a traditional system, for a better return on your investment.
The objectives of these guidelines are to:
Improve the safety, performance and reliability of solar photovoltaic power systems installed in the field.
Encourage industry Best Practice for all design and installation work involving solar photovoltaic power systems.
Provide a network of competent solar photovoltaic power systems designers and installers.
Increase the uptake of solar photovoltaic power systems, by giving customers increased confidence in the design and installation work.
The performance of a reliable installation that fulfills customer expectations requires both careful design and correct installation practice.
PV System Basics
Introduction to relevant Codes and Standards
Permit and Field Inspector Guidelines for PV Systems
Summary of Changes in 2005/2008 National Electrical Code
One promising means of reducing the transmission and distribution losses is through the distributed generation of electricity closer to the end user such as net metering schemes. And the other approach is managing customer consumption of electricity in response to supply conditions, for example, stimulating electricity customers to reduce their consumption at critical times or in response to market prices, thereby reducing the peak demand for electricity. In order to assist consumers to make informed decisions on how to manage and control their electricity consumption, consumers should have a system to monitor their real-time electricity consumption as well as a communication network with the service provider. But traditional electricity meters only record energy consumption progressively over time, normally in monthly basis and provide no information of when the energy was consumed. Therefore the necessity of Advanced Metering Infrastructure (AMI) has been emerged to address the above matters. Nowadays most of the nations are looking to rollout into Smart Meters enabling faster automated communication of information to consumers on their real time electricity consumption, and to service providers.
a smart meter electronically measures how much energy is being used and how much it costs, and then communicates it to the energy supplier and the customer. Smart meters can also enable the provision of new services to consumers as it can record consumption of electric energy in intervals of an hour or less, and also gather data for remote reporting using two-way communication between the meter and central system.
Results of a series of tests designed by the National Renewable Energy Laboratory (NREL) and conducted by PV Evolution Labs (PVEL) to measure the performance of various inverter technologies in various shading conditions were published today. The test determined the annual percentage of energy recovered by power optimizers and micro inverters when compared to traditional string inverter systems in shaded conditions.The results indicate that the SolarEdge optimized system generates 2%, 5% and over 8% more energy than traditional string inverters in light, medium and heavy shading scenarios, respectively.The SolarEdge system outperformed all systems in annual energy production demonstrating higher results than the leading micro inverter solution as well.
"The SolarEdge system yielded more energy than the string inverter system in all tests. On an annual average, the SolarEdge system recovered 24.8% of energy lost due to shading, while the microinverter system recovered 23.2%," says Matt Donovan, PV Evolution Labs.
A presentation by Dr. Tilak Siyambalapitiya on Electricity Costing and Tariffs in Sri Lanka
Visualize the sub-businesses within the power industry, and their stated costs for 2013
How reasonable are the cost components?
Appreciate the correction mechanism
Understand the cost of supply to each customer category
Appreciate the subsidies and surcharges on each customer category
Look at the past and visualize where Sri Lanka got it wrong
Look into the future to examine the cost profiles.
Industry and government decision makers and others
with a stake in the energy sector all need WEO-2012. It
presents authoritative projections of energy trends through
to 2035 and insights into what they mean for energy security,
environmental sustainability and economic development.
SolarEdge Technologies provides next generation power conversion electronics that effectively remove the known system constraints across the photovoltaic energy space. Our Smart DC ASIC technology and active electronics enable cost efficiency and an increased production of clean, grid-ready energy. SolarEdge presents a unique, patent-pending distributed solar power harvesting system, comprised of the following elements:
SolarEdge Power Optimizer
The SolarEdge power optimizer is integrated into each module, replacing the traditional solar junction box. The SolarEdge power optimizers maximize energy throughput from each and every module through constant tracking of the Maximum Power Point individually, per module. Furthermore, the power optimizers monitor the performance of each module and communicate performance data to the SolarEdge monitoring portal for enhanced, cost-effective maintenance. When working with SolarEdge inverters, power optimizers automatically maintain a fixed string voltage, allowing optimal efficiency of the SolarEdge inverter and giving installers greater flexibility to design optimal PV systems.
The independent optimization (IndOP™) technology allows power optimizers to be installed without the need for additional interface hardware and to operate directly with any inverter.
Each power optimizer is equipped with the unique SafeDC™ feature which automatically shuts down modules' voltage whenever inverter or grid power are shut down.
SolarEdge PV Inverter
The SolarEdge Inverter is a highly reliable DC-AC PV inverter. Because MPPT and voltage management are handled separately for each module by the power optimizer, the inverter is only responsible for DC to AC inversion. Consequently, it is a less complicated, more reliable solar inverter. The fixed string voltage ensures operation at the highest efficiency at all times (>97% weighted efficiency) independent of string length and temperature.
SolarEdge PV Monitoring Portal
A web-based application provides module-level, string-level and system-wide monitoring. The solar monitoring software automatically provides alerts for accurate fault detection, localization and remote troubleshooting at the module level. Module performance is communicated across existing power lines, so no extra wiring is required.
SolarEdge provides distributed solar power harvesting and PV monitoring systems. The company’s technology maximizes power generation for residential, commercial and large-scale PV systems.
The SolarEdge portfolio of products includes power optimizers, highly reliable PV inverters and a web portal for module-level monitoring and fault detection.
The fuel sunlight is free and abandon
No running / maintenance or
Almost free of maintenance
Very high warranty periods for the equipments
Supports green concepts directly
Other important benefits
Electricity Tariff can be fixed for the next 25 years
Ease of financial planning
Saving in electricity
Reduced carbon footprint and gain in green credits
Added marketing values for both local and foreign markets
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.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
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
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!
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
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• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
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
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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
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.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024
Problems and Disadvantages in Current Residential & Commercial On-grid PV Systems
1. Problems and Disadvantages in
Current Residential & Commercial
On-grid PV Systems
SolarEdge Technologies
Background
Current technology used in On-Grid PV systems connected in a string of modules so that a voltage
has many drawbacks. The purpose of this paper high enough for DC/AC inversion (150V to 800V) is
is to discuss and categorize the problems and achieved. More power can be added to the system
drawbacks inherent in residential and commercial by adding strings. Since the strings are connected
photovoltaic systems. Typical residential photovoltaic in parallel, they have to match the other strings
installations suffer from numerous problems that in all parameters i.e. type of panels, length and
prevent this technology from realizing its full market orientation. The entire array is connected to a solar
potential. Many of the present problems stem from inverter which is responsible for harvesting the
power losses – whether due to module mismatch, electrical energy and inverting it to AC so it can be
orientation mismatch, or partial shading. Other fed into the grid.
problems stem from system design limitations and
constraints, lack of monitoring and lack of analysis
abilities. In addition, the absence of safety features
poses risks to both workers installing or maintaining
the system, and to firefighters dealing with fires in Inverter
the vicinity of PV installations.
MPPT
For an overview of the SolarEdge distributed power
harvesting system, which overcomes the limitations = ~
of traditional systems, please refer to the SolarEdge
paper “SolarEdge Architecture Overview”.
Typical System Architecture
Current residential PV systems are typically built
from ten to a few hundred PV modules connected in Solar Strings
a series-parallel connection, as shown in Figure 1.
Several panels (10 to 15 typically) are series- Figure 1
1
2. The inverter handles maximum power point tracking 4
for the entire array. This is done by finding the DC
working point in which the most power is harvested
3
from the array. The harvested power is inverted
Ii
from DC into AC power that is fed into the grid. The Ii
inverter is also responsible for conforming to the Ii
2
electrical and safety regulation requirements. IMPP
1
PV System Drawbacks
0
In the following section we will discuss the different 0 10 20 30
U1, U2, U3, UMPP
40 50
causes for power losses in typical PV systems, as
well as other key drawbacks of these systems. Figure 2
Module Mismatch Losses
4
The manufacturing process of PV cells produces Ii
cells with relatively large tolerances in their power Ii 3
Ii
output capability. To reduce the difference between
Ii
cells in the same module, they are sorted during IMPP 2
manufacturing to different power categories (bins)
IMPP_3
and modules are assembled with cells from the 1
IMPP3
same bin. This produces panels with smaller
tolerance variances in output power. The panels IMPP_3
0
themselves are not sorted and panels in the market Ui UMPP_3
today have a 3% tolerance in output power. U1i, U2i, U3i, 3 , UMPP, UMPPi, 3
When several modules are connected in series, 120
each one has a slightly different MPP current. The
100
series connection does not allow the optimal MPP P1i
P2i
current to be drawn from each module. The inverter P3i
80
will select the current which gives the average peak Pi
3
power point of the string or array. This peak power is PMPP
60
always less than the theoretical sum of the individual 40
PMPP1
peak power points of every module. Figure 2 shows
PMPP_3
the I-V and power curves of 3 mismatched modules 3
20
(3% tolerance). In Figure 3 the accumulated I-V and 0
power curves of these modules are shown. It is 0 10 20
Ui
30
UMPP_3
40 50
clear that the string’s peak power point is different U1i, U2i, U3i, 3 ,
UMPP UMPPi, 3
,
from the sum of peak power of the three modules.
Figure 3
120
100
The loss demonstrated here is referred to as
mismatch loss. In standard residential and
P1i
80 commercial PV installations, it can be as high as
P2i
60
5%.
P3i
PMPP
40
20
0
0 10 20 30 40 50
U1, U2, U3, UMPP
2
3. Partial Shading Losses losses are estimated to contribute between 5% to
25% annual power losses.
Partial shading occurs when part of a panel or panels
are shaded, causing different levels of illumination
on the cells in the panel. This can happen due to
shade from the building itself, light posts, chimneys,
trees, cloud fronts, dirt, snow and other light-blocking
obstacles.
Shading on any part of the array will reduce its output,
but this reduction will vary in magnitude depending
on the electrical configuration of the array. Clearly,
the output of any shaded cell or module will be
lowered according to the reduction of light intensity
falling on it. However, since this shaded cell or panel
is electrically connected to other unshaded cells and
modules, their performance may also be lessened
since this is essentially a mismatch situation.
For example, if a single module in a series string is
partially shaded, its current output will be reduced
and this may dictate the operating point of the entire
string. Alternatively, the module’s bypass diodes
may conduct, causing this module to stop producing
power1. Partial shading of crystalline solar modules
will result in dramatic reduction of solar module
output. One completely shaded cell can reduce a
solar module’s output by 40% to 95%.
Figure 4
If several modules are shaded, the string voltage
may be reduced to the point where the open-circuit MPP Efficiency Losses
voltage of that string is below the operating point
of the rest of the array (under voltage situation), The MPPT performance is a very significant aspect
resulting in that string not contributing to the array of the characterization of PV systems, since PV
output. systems, like other systems based on renewable
energies, must harvest the maximum available
The reduction of output from an array with partial energy at every moment from the renewable
shading can be significantly greater than the resource. The global efficiency of the MPPT algorithm
reduction in the illuminated area. This is due to the depends on its ability to make the inverter operate at
loss of output from unshaded cells in the partially the maximum power point (MPP) at every moment.
shaded module, the loss of power from illuminated In order to achieve this, the MPPT algorithm has to
modules in any severely shaded string that cannot accurately track the MPP variations, which can be
maintain operating voltage and the loss of power caused by factors such as irradiance, temperature
from the remainder of the array because the strings variations and partial shading. Obviously, this
are not operating at their individual peak power accuracy will be strongly influenced by both the
points2. amplitude and the dynamics of the variations of the
MPP. MPP losses occur due to two main factors:
For residential systems, it is impossible to avoid all
shading without severely restricting the size of the 1. Static losses caused by the inability of the MPP
array and hence losing output at all times (see Figure algorithm to locate the array’s peak power point. In
4 for examples). In these systems, partial shading some cases, the MPPT algorithm can lock itself in
local maxima.
3
4. 2. Dynamic losses caused by the inability of the process at the end of the day. The second day
MPPT algorithm to track changes in the peak power corresponds to a cloudy day in which atmospheric
point at the right speed. conditions are varying quickly. The figure shows the
evolution during both days of the maximum power
The main cause of static losses in PV systems is local of the generator, obtained from the measured I–V
peaks in the array’s power curve. Shading effects characteristic curves.
cause the array’s power curve to exhibit more than
one maximum power point. More specifically, two or Evolution of the maximum power during day 1
more peak power points appear in the curve, where 4500
different modules contribute power to different local 4000
peaks. Most MPPT algorithms are not designed to 3500
handle local peaks efficiently and when the MPPT
3000
is locked on a local peak, the MPPT efficiency falls
dramatically. Figure 5 shows measured MPPT static 2500
maximum power (W)
efficiency of 4 different inverters in the market3. The 2000
results differ showing losses of 1% to 10%. 1500
1000
500
1 1
0
8 10 12 14 16 18
time (hours)
0.9 0.9
MPPT efficiency
MPPT efficiency
Evolution of the maximum power during day 2
4500
0.8 0.8
4000
3500
0.7 0.7
0 20 40 60 80 100 0 20 40 60 80 100
% of nominal DC power % of nominal DC power 3000
a) PCU A b) PCU B
2500
maximum power (W)
2000
1 1
1500
1000
0.9 0.9
MPPT efficiency
MPPT efficiency
500
0
0.8 0.8 8 10 12 14 16 18
time (hours)
0.7 0.7 Figure 6
0 20 40 60 80 100 0 20 40 60 80 100
% of nominal DC power % of nominal DC power
c) PCU C d) PCU D
With this information, it is possible to calculate
the real maximum energy that could have been
Figure 5 obtained with optimal MPPT during these days. This
value was then compared with the energy effectively
Dynamic losses are directly related to the speed and harvested by the leading PV inverters in the market.
accuracy of the MPPT algorithm. The peak power The comparison of the available energy to that
point shifts mainly due to changes in the irradiance. actually harvested in the first (sunny) day is shown
While these shifts are slow and often monotonous in Figure 7.
under clear, cloudless atmospheric conditions, they
can also be relatively quick during some atmospheric The graph shows how, during most of the day, the
conditions. Figure 6 shows measurements from two MPPT algorithm tracks the maximum power point
consecutive days in Spain4. The first day corresponds quite well. However, during the final part of the day
to a sunny day that is affected by a partial shading (circled in red), due to the process of partial shading,
4
5. the MPPT algorithm fails to track the evolution of System Design and Roof Utilization
the generator maximum power point. During these
hours, the performance of the MPPT algorithm in In addition to the power loss contributors previously
terms of energy harvested from the generator (MPPT discussed, current PV system architecture also
efficiency) is 96%, that is, 4% of the energy has been presents great challenges to installers and system
lost due to the fact that the MPPT algorithm is not designers. The following factors result in a system
able to handle this real life scenario. which is less optimal and, in many cases, smaller
than desired:
Test and characterization of PV commercial inverter (day 1)
4500
4000
Maximum power point
Inverter operating point The string’s voltage is bound by the specific
inverter and MPP (W) and energy (kWh/200)
inverter’s minimum and maximum permissible
3500
power voltages
3000
2500 The strings are placed in parallel and must be
2000
identical in length, combined with the specific
geographical and physical constraints of the roof
1500
energy
1000
When designing the system, the installer has to take
500 into account the inverter’s maximal input voltage
0
and make sure that in the most extreme open-
8 10 12 14
time (hours)
16 18
circuit conditions, the string’s voltage won’t reach
this maximal voltage. This is difficult because many
Figure 7 parameters like voltage tolerance, temperature
variations and sunlight have to be taken into
The results for the second day pattern are shown account. On the other hand, the minimal inverter
in Figure 8. The day is cloudy with quick variations input voltage must be maintained at all times in
in irradiance due to atmospheric conditions. The order to keep harvesting power. Taking into account
MPPT efficiency of the inverter in terms of energy the same parameter changes and the possibility of
extracted from the PV generator is reduced to 95% partial shading in the string make things even more
during the entire day. complicated. In some cases, these constraints lead
to low roof utilization. There are many documented
events5 where installers elected to use a shorter
Test and characterization of PV commercial inverter (day 2)
4500 string in order to increase roof utilization, causing
Maximum power point
system under-voltage during the summer.
inverter and MPP (W) and energy (kWh/400)
4000 Inverter operating point
3500
The roof utilization issue is even more dramatic on
3000 energy commercial roofs, where the roofs’ irregular shapes
2500 and additional obstructions (chimneys, vents, air-
2000 power conditioning units, etc.) increase the difficulty in
selecting just one string length. The average roof
1500
utilization in commercial roofs is 65% to 70% due
1000
to roof-related problems.
500
0 Multi-faceted roofs represent another set of
8 10 12 14 16 18
time (hours)
challenges related to PV Systems. In these cases the
use of multiple inverters enables better utilization
Figure 8 of the roof surface. For example an installation
on a roof with 2 facets (south-east and south-west
facets) will require two inverters or a multi-input
inverter. Both solutions are less cost effective.
5
6. It is clear that the serial-parallel architecture puts Retrofit and Long Term Fault Tolerance
many constraints on the PV system, preventing the
full utilization of the roof and reducing the actual
Another drawback of PV systems is the difficulty of
annual energy harvested from the system.
retrofitting and replacing faulty modules throughout
their life cycle. If a PV module breaks in an installation
(due to extreme weather conditions or accidents),
System Feedback and Troubleshooting it has to be replaced with a module with similar
electrical characteristics, and since PV modules are
Another inherent problem of the serial-parallel improving all the time, it is not possible to use a new
connection is the inability to verify the proper PV module in an old installation. For this reason, PV
installation and operation of every element in the module companies keep an inventory of cells and
system. The only data points available are measured modules for 25 years as a supply for old systems.
at the inverter (input voltage, input power) and The same reason prevents the gradual retrofit of
can only partially assist in evaluating the system old systems—you are essentially stuck with old
performance. technology.
Since usually only overall power output is monitored,
significant problems with an installation can go System Safety
undetected yet cost the owners 10% or more of
their energy payback. Without actionable diagnostic The safety of PV systems has always been an
information, the only alternative when operating issue of concern. Over the years, many codes and
problems are suspected is to deploy technicians to standards were devised and discussed to improve
the site to search for the problem with little direction the safety of these systems. Two main safety issues
or guidance. This search becomes more difficult remain:
as the installation size increases. The average
commercial solar site installed in California in 2004 1. The risk of electrocution while installing the
had 1,000 solar modules, making this difficulty very system. Even the series connection of two PV
real. modules exposed to sunlight generates an unsafe
voltage with enough power to kill whoever touches
The parallel connection of strings prevents the the exposed contacts. Many work procedures and
detection of defective modules and in some cases safety precautions employed during the installation
the detection of a disconnected string. For example, processes slow the work but maintain employee
in a system with 8 strings, the detection of 12.5% safety.
power loss, which is equivalent to one string, is
not trivial, especially since the system’s expected 2. The risk to firemen during a fire. The first thing
power output is dependant on all the other criteria firemen do in a building fire is cut the power. This
mentioned above. enables them to spray water and use axes to cut
holes in the roof to let smoke out. These actions
Even when a fault is suspected and technicians are dangerous when PV systems are installed on
are sent to the site, maintenance is expensive the roof. Firemen are trained to cut the power to
because it requires the deployment of skilled the building. After doing so, they believe that there
technicians to the solar site. Once on-site, is no power source that can endanger them. In
their only recourse is to dismantle the system PV installed buildings cutting the power does not
and search for the cause of the failure. eliminate the dangerous voltages present at the
The same lack of feedback also increases the initial string ends. Firemen preparing to chop a hole in
installation time due to lengthy verification and the roof or to use water could be electrocuted6.
debugging. Regulatory bodies and firefighting officials are
pushing for new regulations that will ensure the
shutdown of PV modules in case of fire.
6
7. Conclusion
We described the structure of PV systems and several
drawbacks and disadvantages in the way these
systems are designed and built. Though previous
works focused on improving different aspects of
photovoltaic systems, no single holistic approach
was presented that could solve many of the current
problems present in PV installations. SolarEdge
Technologies distributed power harvesting system is
the only power harvesting system and architecture
that offers a full, robust solution that harvests up to
25% more energy and resolves the issues described
in this paper.
1
“Effects of Reverse-Biased PV Cell in Panels”,
SolarEdge Technologies (2006)
2
“Photovoltaic Modules, Systems and Applications”,
Nicolla M. Pearsall & Robert Hill (2001)
3
“Performance Assessment of the Inverter based
Grid Connection of Photovoltaic Systems”,
Gianfranco Chicco, Roberto Napoli, Filippo Spertino
(2004)
4
“On the Testing, Characterization, and Evaluation
of PV Inverters and Dynamic MPPT Performance
Under Real varying OperatingConditions”, Pablo
Sanchis, Jesu´s Lo´pez, Alfredo Ursu´a, Eugenio
Gubı´a and Luis Marroyo (2007)
5
“PV Installations, A Progress Report”, John C.
Wiles, Bill Brooks, Bob-O Schultze (2002)
6
“Commercial Building Product Magazine”, (2007)
7