Rozprawy doktorskie na temat „DTU PV POWER PLANT”

One of the most pressing problems nowadays is climate change and global warming. As it name indicates, it is a problem that concerns the whole earth. There is no doubt that the main cause for this to happen is human, and very related to non-renewable carbon-based energy resources. However, technology has evolved, and some alternatives have appeared in the energy conversion sector. Nevertheless, they are relatively young yet. Since the growth in renewable energies technologies wind power and PV are the ones that have taken the lead. Wind power is a relatively mature technology and even if it still has challenges to overcome the horizon is clear. However, in the PV case the technology is more recent. Even if it is true that PV modules have been used in space applications for more than 60 years, large scale production has not begun until last 10 years. This leaves the uncertainty of how will PV plants and modules age. The author will try to analyse the aging of a specific 63 kWp PV plant located in the roof of a building in Gävle, monitoring production and ambient condition data, to estimate the degradation and the new nominal power of the plant. It has been found out that the degradation of the system is not considerable. PV modules and solar inverters were studied, and even if there are more elements in the system, those are the principal ones. PV modules suffered a degradation of less than 5%, while solar inverters’ efficiency dropped from 95,4% to around 93%.

This thesis work focuses on the design of a hybrid PV-Gasification-Battery plant for a remote villagelocated on an Indonesian island and currently not electrified. As the objective of the study is to assess therelevance of the hybrid plant to make use of the local resources to satisfy the demand, the village situationis analyzed, and a representative load curve is built. The consumption of the whole village whose 3000households mainly live from fishing is assumed to reach 13.3 MWh/day by the plant year 10, peaking at920 kW at 6 pm. The local situation study raises important issues such as deforestation, lack of drinkablewater and food conservation solutions. This project not only intends to bring electricity access but adoptsan integrated and innovative approach to best serve the local needs and address the above-mentionedissues. This is why virtuous practices such as polygeneration with cooling, ice and clean water productionor load shaving are embraced. To determine its optimal sizing and behavior, a modelling of the plant isdeveloped, with a specific focus on the gasification plant operation and technical limits, and simulationsare carried out. The scenario in which the gasification plant runs at half load during the day while all thephotovoltaic power available is injected proves to be the best one as it engenders a smooth power curvewith a limited peak and a balanced ratio biomass/solar in energy. As for the optimal sizing, it is found tohave respective PV, gasification and storage capacities of 1600 kWpeak, 450 kW and 1274 kWh. It isdefined as optimal with regards to its performance on the three main criteria, introduced to make sure thataffordability, reliability and environmental sustainability remain at the core of the project. Indeed, theLevelized Cost of Energy (LCOE) is the lowest of all simulations and remains in the range of tariffsevoked by the Indonesian energy distributor PLN for Power Purchase Agreements in off-grid areas with141$/MWh, the 5%-minimum criterion is met for the share of blackout and the plantation size remainsreasonable with less than 50 hectares required. This configuration is finally compared to other hybridsolutions, both the association of PV and batteries and the PV-genset-storage solution boast higherLCOE with 286 and 157$/MWh respectively.
Denna magisteruppsats undersöker en konstruktion av ett kraftverk för en by i Indonesien som förnärvarande saknar elförsörjning. Konstruktionen görs med hjälp av fotovoltaik-förgasnings-batterier.Syftet med studien är att bedöma hybridkraftverks förmåga att utnyttja lokala naturresurser och om de ärkapabla att tillgodose byns behov. Därför analyseras byns situation och presenteras med en representativbelastningskurva. Förbrukningen av hela byn, det vill säga 3000 hushåll som försörjer sig huvudsakligenvia fiske, uppskattas till 13,3 MWh/dag för kraftverks år 10. En lokal undersökning tydliggör trehuvudproblem: avskogning, brist på drickbart vatten och brist på möjlighet att förvara mat. Projektetsyftar inte bara till att ge tillgång till el utan också till att tillgodose andra lokala behov. Därför används ettintegrerat och innovativt tillvägagångssätt: kylning, is och dricksvatten produceras; belastningsutjämningtillämpas. En modell utvecklas för att bestämma optimal dimensionering som fokuserar påförgasningskraftverkets drift och tekniska begränsningar. Därutöver utförs simuleringar. Bästa scenariouppstår när förgasningskraftverket körs vid halv belastning under dagen medan all tillgänglig solkraftutnyttjas, eftersom kraftproduktionen är jämn och peaken under dagen är begränsad samtenergiförbrukningen av sol/biomassa är balanserad. Den optimala konfigurationen är för respektive PV-,förgasnings- och batteris kapaciteter 1600 kWpeak, 450 kW och 1274 kWh. Det definieras som optimaltbaserat på tre huvudkriterier som bedömer kraftverkets överkomlighet, tillförlitlighet och miljöhållbarhet.LCOE (Levelized Cost of Energy) visar att det är det billigaste jämfört med de andra simuleringarna på141 $/MWh. Andelen blackout uppfyller 5 %-målet och plantagen har en rimlig storlek under 50 hektar.Slutligen jämförs den optimala konfigurationen med andra hybridkraftverk som båda är dyrare: PVbatterikraftverkmed en LCOE på 286$/MWh och PV-genset-batterikraftverk med en LCOE på157$/MWh.

Finding the optimum inter-row spacing and installation tilt for tilted or ground mounted PV systems is a big issue in designing the large-scale PV systems. Increasing the array spacing leads to higher annual generated energy because of the reduced impact of row-shading, but on the other hand, it increases costs of land purchase/lease and wiring costs. Many compromises between performance and cost should be done to design an optimum large-scaled solar plant. One of the criteria in designing of solar power plants is reducing of LCOE, which reflects the cost of every unit of generated energy. Site locations have large impacts on the optimal design of pitch distance and title angles, but such impacts have not been studied extensively in the existing studies, so it is going to bridge this research gap in this thesis.   The main purpose of this research is to investigate the impact of climate conditions on the pitch distance and tilt angle for large-scale PV plant and finding the optimal pitch distance and tilt according to the least cost of production. The impact of climate and meteorological data on the self-shading loss and yield of energy are investigated through a simulation tool, which is PVsyst software here, in different tilt angles and distances between rows. The different climates can be considered by choosing site locations in different latitudes to cover all climate zones. Six cities in temperate climate, three cities in tropic climate and one city in polar climate have been selected. LCOE minimizing is a measure in finding the optimum tilt and pitch distance for a 1 MW solar system installed in different latitudes. In this study the type, size and cost of components have been assumed constant in different climate conditions. There is a wide range of variability in some economic indicators like interest rate and discount rate as well as the cost of land in different climates or even countries in the same climate; then to highlight the impacts of climate conditions on the optimal tilt and pitch distance, these parameters were assumed to be constant in this study.   The results show the optimal tilt of angles increases with getting far of equator in a range between 0° and 40° to capture more direct sunlight, and the optimal raw spacing grows in further locations to equator in a range between 4 m to 11 m to reduce self- shading loss. Moreover, the best module configuration for PV arrays (portrait or landscape) can be different in different climates.

This research thesis covers the latest research on renewable energy globally and focuses on the solar panel and biofuels market. A full macroeconomic analysis is done on the Chinese Taipei, and this results in some parameters which then become the basis of this research. The macroeconomic parameters are then put into a tabular form and applied to India, Turkey and Australia to see how much weight the analysis can hold and if there is enough data per country on the macroeconomic parameters chosen. This research thesis conducts a shorter, custom version of a macroeconomic analysis on a South African area, and considers the national Gross Domestic Product, pollution, length of transmission lines, weather factors such as sunlight and temperature and more. Following from this, a hybrid power system is developed under these circumstances and the information is compared with past research. A very informative discussion is then had as to what the model means on a macroeconomic scale and how it performs technically. The technical solution at this point has no economic barriers. Economics can be a tool and not a financial hurdle in the face of technological advancement.

The aim of the Thesis is theoretical clarification of the issues of photovoltaic power plants, their diagnostics, inspection and performance measurement, including negative impacts on their operation and subsequent application of theoretical knowledge during practical inspection and diagnostics of PV power plants. In its introductory part, the Thesis deals with design, manufacturing and development of PV cells and panels and describes other necessary elements and components, including their use in individual types of photovoltaic systems. Another part describes electric parameters of PV cells and panels, especially the parameters that can be found out by measurement of V-A characteristics and also the parameters affecting the shape of the V-A characteristics. The third part is focused on failures of photovoltaic systems, which include various defects of photovoltaic cells and panels, it also provides for adverse factors affecting operation of the entire system, associated not only with weather influences but also with the actual design of the photovoltaic system. The fourth part deals with possibilities of increasing the cost-effectiveness of electricity generation by PV power plants on the basis of practical experience of their operators. The subsequent part determines, on the basis of technical standards, procedures for PV power plant inspections, the procedures for measurement and diagnostics of PV power plants and also other prerequisites connected with inspections and measurements. This part includes also a description of requirements for measuring devices, most frequent measurement errors, adverse impacts affecting measurements and methods of assessment of the data measured. The last part of the Thesis is practical. At first it deals with verification of the impact of defects of PV modules on the shape of their V-A characteristics, then with execution of inspections and diagnostics of a particular PV power plant, evaluation of the data identified and measured, as well as with a proposal of optimisation measures to increase cost-efficiency of the operation of that particular PV power plant.

The current energy situation is taking a turn towards renewable energies, due to the new pacts to curb global warming. These agreements, together with governmental aid, are facilitating an escalation in the production and improvement of new energy systems and the price decrease due to a larger-scale production. Within these energy alternatives, solar energy is found, specifically the subject to be treated in this project is photovoltaic energy, due to its exponential growth in the last 10 years, new tools are being developed for its monitoring and modelling. Therefore, the main objective of this thesis is to develop a method  for installation testing of a PV-system. The method should give the installed nominal power of the system and show if the maximum power point trackers work as expected. A large PV-system was installed on the roof of Gävle Arenaby during 2017. A measurement system for monitoring of the power of the system and of the solar irradiance was installed. Different parameters have been taken into account for the adjustment of the model that vary the performance of the system. These factors are: the irradiance received, the module temperature and the angle of incidence. It has been concluded that the results obtained indicate a correct adjustment of the theoretical power against the real power, which means, a correct operation of the generated model. Besides, the expected power follows a linear trend, reaching the power set by the manufacturer for Standard Test Conditions. The results show that the monitored modules-strings fulffill the promised performance and the method for installation testing work as expected. The linear correlation between corrected power and irradiance means that the maximum power point tracker in the inverter works independent of the power.

Main purpose of the thesis is to create proposal of the photovoltaic hybrid system for commercial building in accordance with applicable rules for energy savings program. The introductory part of the thesis describes the rules regarding the photovoltaic system parts. The next part of the thesis describes the available technical solution for realization of the photovoltaic system design and the possibilities of electric energy accumulation in these systems and how to deal with power overflows using the power flow controller and what is the negative impacts on the distribution network when switching the connected load. In the next part the design of the PV system is carried out according to the valid assumptions described in the theoretical part of the thesis. Verification of power flow controller and measurement results in UEEN laboratories. The last part of the thesis is an evaluation of the economic part of the proposed system.

Fossil fuels and non-renewable resources are being replaced with, as modern day society has coined the term, green energy. This movement towards green energy creates a demand for renewable energy resources, such as solar photovoltaic (PV) systems. This study used Geographic Information Systems (GIS) in conjunction with Remote Sensing (RS) practices and two weighting systems the Analytical Hierarchy Process (AHP) and Rank-Order methods for PV site selection. Six multi-criteria models were developed using spatial factors and constraining images to locate potential photovoltaic power plant sites for three settings of fixed axis PV arrays. This analysis was performed at a macro regional scale and further analysis is encouraged for micro site selection.

O objetivo deste trabalho é modelar a arquitetura de uma usina solar fotovoltaica arrefecida intitulada UFVa, utilizando um protótipo de verificação. A metodologia se baseia na medição, verificação e análise dos dados de temperatura e produção de energia elétrica dos strings de teste (arrefecido) e comparação (não arrefecido), estudo do comportamento da alimentação de água do sistema de arrefecimento e o impacto das condições climáticas na operação do protótipo de UFVa. Por meio das análises dos dados constatou-se que, para o período entre as 09h00min e as 17h30min, os módulos PV do string de teste sempre operam com temperaturas inferiores aos módulos PV do string de comparação. Durante o período de testes, no qual a temperatura dos módulos PV do string de comparação operou acima de 55,0°C, as temperaturas médias e máximas registradas nos módulos PV do string de teste foram inferiores a 37,0 °C, operando sempre abaixo da temperatura nominal de operação da célula (NOCT). A produção de energia elétrica no string de teste superou a do string de comparação em 3,0kWh/dia. Portanto, o sistema de arrefecimento reduz a temperatura de operação dos módulos PV, principalmente no período de máxima geração elétrica, que corresponde ao período das 11h00min às 15h00min, proporcionando ganhos médios de rendimento de 5,9% na produção de energia, 10,3% na potência e 5,4% no FC.
In this work we use a verification prototype to model the architecture of a solar photovoltaic power plant equipped with a cooling system. The power plant we model is called UFVa. The methodology is based on the measurement, verification, and data analysis of temperature, electricity generation, test strings (cooled) and comparison strings (not cooled), along with a study of the water feeding behavior of the cooling system, and the impact of climatic conditions in the UFVa prototype operation. By analyzing the data we observed that, for the period between 09:00am and 5:30pm, the PV modules of the test string operate at temperatures below those of the PV modules of the comparison string. During the tests, in which the temperature of the PV modules of the comparison string operated above 55.0°C, the average and the maximum temperatures recorded in the PV modules of the testing string lied below 37.0°C, operating below the NOCT. Regarding the generation of electricity, the test string generated 3.0 kWh/day more than the comparison string. Hence, the cooling system decreases the operating temperature of the PV modules, particularly during the maximum power generation period which is from 11am to 3pm. This leads to efficiency average gains of up to 5.9% in the generation of electricity, 10.3% in the power, and 5.3% in the PR and PF.

The main point of this thesis is the extension of the complex solar radiation simulator, the creation of new functionalities, and the cooperation of this complex simulator with the PV power plant. This work builds on the work done in the area of solar radiation modeling. The thesis deals with the continuation, or improvement of some shortcomings, removing shortcomings, such as fixing the beginnings and ends of the simulation, correcting the calculation of sunrise and sunset, but also adding different types of clouds, combinations of different preset cloud situations, or data input, and more. These deficiencies are found in the bachelor's thesis "Complex Simulator of the solar irradiance", and PSCAD is the main tool in this work. Another important point of this work is the realization of the simulation where an improved solar radiation simulator works in cooperation with a model of a photovoltaic panel or a PV power plant, respectively. It has different operating states created in PSCAD. These include, for example, cloud crossings, both over the entire power plant and only partial. In addition, there are experiments that prove the fact that the direction of the incoming cloud plays a role in the power of the PV power plant.

Renewable energy resources, especially photovoltaics, have experienced enormous boom all over the world in the past few years. It was completely the same in Czech Republic where you would not find anybody without his own opinion regarding PV business. Installation of PV power plants has become very attractive business, with very significant role in 2011 in Czech Republic. At this time, this solar boom has found its "home" in other European countries, particularly in Eastern Europe. The post of the new Eastern Europe's "powerhouse" can defend even Romania, that's the cause I have chosen this country as the subject of this thesis. The aim of this thesis is to create a business plan for PV power plant and evaluate the investment opportunity of its installation in Romania. And then by means of a sensitivity analysis find out the impact of external factors that can significantly affect the profitability of the project.

Este trabalho apresenta um estudo de medições e simulações de fluxo harmônico na Usina Solar Fotovoltaica do Estádio Mineirão em Belo Horizonte/MG. O objetivo foi verificar o comportamento dos inversores solares fotovoltaicos na geração de harmônicos e a atenuação ocorrida pela agregação de múltiplos inversores. Para isso, foram realizadas medições em seis pontos estratégicos da usina investigada, por meio de analisadores de qualidade de energia, o que possibilitou a verificação do comportamento da usina em horários distintos e condições climáticas diversas. Foi avaliada a injeção de harmônicos no sistema elétrico pelos inversores e comparados os valores com os limites previstos em normas, procedimentos e recomendações vigentes. Além disso, o modelo completo da usina foi desenvolvido e simulado utilizando os softwares OpenDSS, ANAH e PowerFactory para análise harmônica e sua validação com os dados de medição. Os resultados obtidos indicam boa conformidade das medições e adequações dos modelos desenvolvidos.
This work presents a study of harmonic measurements and flow simulations in Photovoltaic Solar Plant of the Mineirao Stadium in Belo Horizonte/MG. The objective was to verify the behavior of photovoltaic solar inverters in the generation of harmonics and the attenuation occurred by the aggregation of multiple inverters. For this, measurements were performed on six strategic points of the investigated plant through power quality analyzers, allowing the verification of the plant's behavior at different times and different climates. It was evaluated the injection of harmonics in the electrical system for inverters and compared the values with the limits laid down in standards, procedures and current recommendations. In addition, the complete model of the plant was developed and simulated using the OpenDSS, ANAH and PowerFactory softwares to harmonic analysis and its validation with the data measurement data. The results indicate good agreement between measurement and developed models.

Energy plays a key role in both the economic growth & prosperity of the country. It determines the pace of development of the developing countries. There is a close relation between the Energy & future growth of a nation. Not only in India but also in the whole world, there is a never-ending and diverging need for energy. Since, ancient times, the energy are derived from one source or another. In much older periods, the demand for light & fuel was met with traditional sources like wood or animal dung or waste plants. Later they got replaced by coal, water & nuclear energy which were then available in abundance. But, as the time goes on, the limitations & drawbacks are stepping forward making the hunt for alternative sources of energy a must, considering the future generation & their needs with a long term vision. As its high time to think upon the quality of the environment, more and more awareness is generating for making the use of the environment friendly resources and products. Though sunlight is considered to be a “convincing solution” to the “need for clean, abundant, cheaper, renewable and environment friendly source of energy,” solar energy currently provides only about 0.01 percent of the total electricity supply needs; this indicates the huge scope of solar SPV in a sub-tropical country like India and rest of the world. Further, recent market trends, regulatory pressures, consumer incentives, and rapid technological advancements are together driving solar energy costs drastically down relative to conventional fossil fuel-derived energy. Now Solar Power is more affordable to common people as compared to the previous era and the only thing, which is missing, is the awareness to be spread about this environment friendly and clean source of energy. Compared to conventional and other renewable energy sources, solar power is especially attractive because it can be easily scaled up Solar electricity can also be generated nearer to consumers and even on site, which greatly reduces or eliminates transmission costs and losses. It always available to us as ready to use source of energy in the daytime. Furthermore, the increasing adoption of variable pricing or net metering schemes also favours solar electricity. Under these schemes electricity rates are higher when peak demand is highest and this generally correlates to when more solar energy is available and electric output highest. Solar PV/module costs are also presently being lowered through higher volume production, improved manufacturing techniques, and alternative solar technologies, reduced size of solar V | P a g e panels due the lesser use of semiconductor material and increased efficiencies of the solar panels. Total costs of installed system of Solar Photovoltaic (SPV) systems are further being minimized through economical “balance-of-system” components such as inverters through improved design and installation techniques. Fundamentally, the solar industry as a whole has advanced and grown to the point where solar solutions are not only an environment friendly option but also a cost effective too. The Ministry of Power (MoP) has an obligation to promote and support co-generation technologies and renewable sources for Power generation under the supervision of Nodal agencies and henceforth it will play a major role in mainstreaming renewable energy sector with other conventional energy sources in India. In view of the efforts of government and favourable government policies in renewable sector has compelled various agencies and institutions to look forward in this regard. Delhi technological University has took a step forward and decided to have a SPV rooftop system of 432 KW power. Assuring robust project design, reliability and best support, M/s Hero Future Energies Limited got this opportunity to implement a 432 kW SPV power Plant under the supervision and guidance of the esteemed professors on the rooftops of the buildings of the Delhi Technological University. This research work brings out the technical details & overall cost mitigating this pioneer project. The total power to be produced by the solar cells will be 432 kW. The cell technology, which is being used, is crystalline type. The main objective of this project is to study the economic feasibility and practicality of the of the rooftop solar power systems, also to assess the environmental impact of these type of SPVs. Now days we are in the era of rapid development, which require exponential growth of energy demand. Due to this increasing energy demand the burden on fossil fuels is rising which is a major concern for the sustainable development and healthy environment. Therefore, to avoid this huge concern a way out is to be required some reliable, renewable and clean energy sources is required. Solar power is one the best solution of this problem and must be focused to make it more practical and accessible to the common people. Keeping this thing in mind this particular project related to 432 KWp rooftop solar photovoltaic power plant installed at the campus of Delhi Technological University is chosen so as to enhance the understanding in the practicality of the PV modules and to analyse their design and feasibility in the real world. VI | P a g e As we, all are aware that government is also serious in this regard & has taken many game changer decisions in this field like subsidised solar panels, industry favoured policies for the SPV manufacturers etc. Government of India has recently started JNNSM program to promote solar projects in India. Under this program, many policies are coming in MW scale project as well as in roof top level. Most of industries are running on conventional sources like coal-based energy, diesel sets etc. According to this policy, any industry, commercial, domestic can plan to set up a solar project for their captive consumption. For this purpose, they can use their un-utilized space like space available on roof, sheds, BIPV etc. Till the time all rooftop policies are for captive consumption only. Some of state governments have started some initiatives for net metering policy. Under this scheme, if any solar project has excess generation (which is more than their individual load demand), they can feed that generation to utility grid. This scheme will take some time to finalize. All solar projects that are to be implemented under this policy will be mounted on roofs; sheds etc. only and total power generation from solar will be used in-house only. There is a huge potential available for generating solar power using unutilized space on wastelands, shedding and rooftops around buildings. In fact, small quantities of power generated by each individual household, industrial building complex, commercial building complex or any other type of building can be utilized to partly fulfil the power requirement of the building occupants and surplus, if available, can be fed into the grid. The rooftop SPV systems on building’s rooftops can be installed to substitute DG’S for operation during load shedding. As an advantage setting up the grid interactive solar power plants on the rooftops would help in reducing the consumption of diesel fuel during the day time in the areas where grid power is intermittent. If the grid power is continuous, the solar power generated will be utilized along with the grid power and accordingly the proportionate amount of grid power usage will be reduced. During minimum load periods (e.g. during weekends, holidays etc.), the excess/surplus power generated from solar systems (SPVs) could be fed into the grid. In turn, the State Government can compensate the consumer for the exported/traded power as per policy. Connectivity of these projects to the grid also has to be in agreement with the prevailing CEA guidelines or policy by the State regulators/ DISCOMs. VII | P a g e The work for making DTU a clean energy developing university was assigned to M/s Hero Solar Energy Pvt. Ltd. Who is pioneer in this field and has working parallel on many other projects like as follows: 1. Indraprastha University (GGSIPU, Dwarka, Delhi) 2. Netaji Subhash Institute of Technology (NSIT, Dwarka, Delhi) Delhi Technological University (DTU) until 1962, the college was under the direct control of Ministry of Education, Government of India. But, in 1963 the administration/command of the college was handed over to Delhi Administration. Delhi College of Engineering (DCE) was under the direct administrative control of Department of Technical Education & Training, Govt. of NCT of Delhi. For academic purposes, the college was initially affiliated to University of Delhi since 1952. Whereas, from July 2009, the Delhi College of Engineering (DCE) has become Delhi Technological University (DTU) vide Delhi act 6 of 2009. The erstwhile Delhi College of Engineering has functioned/operated from its historic Kashmiri Gate Campus for about 55 years and has shifted in 1996 to its lush green sprawling campus of 164 Acres at Bawana Road, adjoining Sector-17, Rohini, Delhi-110042. Its shifting to its new campus has added new dimensions of research and triggered innovations in plenty, which has received high national and international acclaim. As Delhi Technological University (DTU), it has the desired self-sufficiency to outshine and shape itself as a world class Technological University. Now DTU is heading towards the green and clean energy university title. Therefore, it was decided to conduct detailed study on this rooftop SPV system to analyse its mathematical analysis, feasibility and profitability.

abstract: This is a two part thesis: Part – I This part of the thesis involves automation of statistical risk analysis of photovoltaic (PV) power plants. Statistical risk analysis on the field observed defects/failures in the PV power plants is usually carried out using a combination of several manual methods which are often laborious, time consuming and prone to human errors. In order to mitigate these issues, an automated statistical risk analysis (FMECA) is necessary. The automation developed and presented in this project generates about 20 different reliability risk plots in about 3-4 minutes without the need of several manual labor hours traditionally spent for these analyses. The primary focus of this project is to automatically generate Risk Priority Number (RPN) for each defect/failure based on two Excel spreadsheets: Defect spreadsheet; Degradation rate spreadsheet. Automation involves two major programs – one to calculate Global RPN (Sum of Performance RPN and Safety RPN) and the other to find the correlation of defects with I-V parameters’ degradations. Based on the generated RPN and other reliability plots, warranty claims for material defect and degradation rate may be made by the system owners. Part – II This part of the thesis involves the evaluation of Module Level Power Electronics (MLPE) which are commercially available and used by the industry. Reliability evaluations of any product typically involve pre-characterizations, many different accelerated stress tests and post-characterizations. Due to time constraints, this part of the project was limited to only pre-characterizations of about 100 MLPE units commercially available from 5 different manufacturers. Pre-characterizations involve testing MLPE units for rated efficiency, CEC efficiency, power factor and Harmonics (Vthd (%) and Ithd (%)). The pre-characterization test results can be used to validate manufacturer claims and to evaluate the product for compliance certification test standards. Pre-characterization results were compared for all MLPE units individually for all tested parameters listed above. The accelerated stress tests are ongoing and are not presented in this thesis. Based on the pre-characterizations presented in this report and post-characterizations performed after the stress tests, the pass/fail and time-to-failure analyses can be carried out by future researchers.
Dissertation/Thesis
Masters Thesis Engineering 2015

碩士
國立中央大學
國際永續發展碩士在職專班
103
The objective of this thesis is to assess the prefeasibility of a photovoltaic (PV) power plant for rural electrification in Honduras to improve the reliability and redundancy of the grid. The proposed location of the power plant is at Alianza, Valle in a region has an average global horizontal irradiation of 6.09 kWh/m2/day; one of the highest irradiance registered in the country. The proposed size of the PV power plant is 720 kWp which is equal to the highest demand by the community in the 20 years lifetime of the project The assessment is based on the monthly average irradiance data from the Solar and Wind Energy Resource Assessment Program (SWERA). The technical assessment is performed with the software PVsyst, a tool for designing PV systems. The financial assessment of the project is evaluated using the software RETScreen, widely used software for the analysis of renewable energy technologies. The assessment analyzes two configurations for the tracking system, fixed-tilt and one-axis tracking. The PVsyst results for the technical assessment provide that the one-axis tracking generates an additional 25% electricity output over the fixed-tilt PV, 1598 MWh and 1,270 MWh, respectively. The financial indicators of the fixed-tilt and one-axis tracking PV, provided by the results of the assessment in RETScreen, estimate an internal rate of return of 8.9% and 13.9%, respectively. The equity payback time is calculated at 13.2 years for the fixed-tilt and 10.7 years for the one-axis configuration. The B-C ratio is estimated at 1.60 for the fixed-tilt and at 2.89 for the one axis configuration. These financial indicators suggest profitable conditions for both scenarios. The sensitivity analysis indicate the flexibility of the one-axis tracking scenario, by reducing the electricity export rate and increasing the initial costs, the results still provided profitable financial indicators.

碩士
國立臺北科技大學
電機工程系
107
Large photovoltaic (PV) plant with capacity over several hundreds mega watts need to be interconnected to the very high voltage (VHV) transmission system. In general, the fault impact of large PV plant on the power system is very serious. Good protection coordination and insulation coordination are required for reducing the fault impact on power system, where the system grounding is a key affection factor in the large PV power plant; the system grounding of VHV system is determined by the grounding of main transformer neutral point, while for high voltage system, the solid grounding or low resistance grounding can be used. However, the system grounding of low voltage system shall be compatible with inverter design, which may be the solid grounding, non-grounding and ground-potential-transformer (GPT) grounding. The system ground fault and surge characteristics will be different under different system grounding such that it has large affection on ground fault protection coordination and surge protection coordination (insulation coordination). In this thesis, the relative problems of system grounding are surveyed. At the first, system modeling for the simulations of ground fault and surge characteristics is constructed based on the alternative transient program of electromagnetic transient program (EMTP-ATP). For the ground fault characteristic, the fault currents, phase voltage and ground potential rise (GPR) on VHV system, high voltage system and low voltage system are analyzed, while the surge characteristic aim to surge phase voltage and surge GPR from lightning surges. Based on these analysis results, the affections of various system groundings on the ground fault protection coordination and insulation coordination at high and low voltage systems are reviewed. Furthermore, the advantages and defects of various system grounding are compared and the risks are evaluated. Finally, the strategies for improving the associated defects are proposed including the selection of system grounding type and the suggestion of protection coordination and insulation coordination planning. Thereby, the performances of ground protection and surge protection are reinforced such as upgrading the power supply safety and reliability of large PV power plants.

abstract: The object of this study was a 26 year old residential Photovoltaic (PV) monocrystalline silicon (c-Si) power plant, called Solar One, built by developer John F. Long in Phoenix, Arizona (a hot-dry field condition). The task for Arizona State University Photovoltaic Reliability Laboratory (ASU-PRL) graduate students was to evaluate the power plant through visual inspection, electrical performance, and infrared thermography. The purpose of this evaluation was to measure and understand the extent of degradation to the system along with the identification of the failure modes in this hot-dry climatic condition. This 4000 module bipolar system was originally installed with a 200 kW DC output of PV array (17 degree fixed tilt) and an AC output of 175 kVA. The system was shown to degrade approximately at a rate of 2.3% per year with no apparent potential induced degradation (PID) effect. The power plant is made of two arrays, the north array and the south array. Due to a limited time frame to execute this large project, this work was performed by two masters students (Jonathan Belmont and Kolapo Olakonu) and the test results are presented in two masters theses. This thesis presents the results obtained on the north array and the other thesis presents the results obtained on the south array. The resulting study showed that PV module design, array configuration, vandalism, installation methods and Arizona environmental conditions have had an effect on this system's longevity and reliability. Ultimately, encapsulation browning, higher series resistance (potentially due to solder bond fatigue) and non-cell interconnect ribbon breakages outside the modules were determined to be the primary causes for the power loss.
Dissertation/Thesis
M.S.Tech Electrical Engineering 2013

abstract: The operating temperature of photovoltaic (PV) modules is affected by external factors such as irradiance, wind speed and ambient temperature as well as internal factors like material properties and design properties. These factors can make a difference in the operating temperatures between cells within a module and between modules within a plant. This is a three-part thesis. Part 1 investigates the behavior of temperature distribution of PV cells within a module through outdoor temperature monitoring under various operating conditions (Pmax, Voc and Isc) and examines deviation in the temperature coefficient values pertaining to this temperature variation. ANOVA, a statistical tool, was used to study the influence of various factors on temperature variation. This study also investigated the thermal non-uniformity affecting I-V parameters and performance of four different PV technologies (crystalline silicon, CdTe, CIGS, a-Si). Two new approaches (black-colored frame and aluminum tape on back-sheet) were implemented in addition to the two previously-used approaches (thermally insulating the frame, and frame and back sheet) to study temperature uniformity improvements within c-Si PV modules on a fixed latitude-tilt array. This thesis concludes that frame thermal insulation and black frame help reducing thermal gradients and next best viable option to improve temperature uniformity measurements is by using average of four thermocouples as per IEC 61853-2 standard. Part 2 analyzes the temperature data for two power plants (fixed-tilt and one-axis) to study the temperature variation across the cells in a module and across the modules in a power plant. The module placed in the center of one-axis power plant had higher temperature, whereas in fixed-tilt power plant, the module in north-west direction had higher temperatures. Higher average operating temperatures were observed in one-axis tracking as compared to the fixed-tilt PV power plant, thereby expected to lowering their lifetime. Part 3 focuses on determination of a thermal model coefficients, using parameters similar to Uc and Uv thermal loss factors used in PVsyst, for modules of four different PV technologies experiencing hot-desert climate conditions by statistically correlating a year-long monitored data. Thermal models help to effectively quantity factors influencing module temperatures to estimate performance and energy models.
Dissertation/Thesis
Masters Thesis Mechanical Engineering 2016