Comparative study of different hill climbing MPPT through simulation and experimental test bed

Hill climbing MPPT technique is commonly used in photovoltaic systems in order to achieve maximum power from it. Due to the massive numbers of the MPPT techniques in this field, it becomes essential to find and verify the most effective, simplest and reliable technique to be used. In this paper comparative studies of two different climbing MPPTs that are conventional perturb and observe and modified perturb and observe has been performed. The paper verifies their tracking performance through calculations. Simulations are also performed using MATLAB SIMULINK and results are analyzed. In addition, hardware implementation has been carried out which verifies simulation results. This study should serve as a strong evidence for practical feasibility of the modified perturb and observe method for MPPT

Applications and efficiencies of the first cat 63K DNA array

The development of high throughput SNP genotyping technologies has improved the genetic dissection of simple and complex traits in many species including cats. The properties of feline 62,897 SNPs Illumina Infinium iSelect DNA array are described using a dataset of over 2,000 feline samples, the most extensive to date, representing 41 cat breeds, a random bred population, and four wild felid species. Accuracy and efficiency of the array\u2019s genotypes and its utility in performing population-based analyses were evaluated. Average marker distance across the array was 37,741 Kb, and across the dataset, only 1% (625) of the markers exhibited poor genotyping and only 0.35% (221) showed Mendelian errors. Marker polymorphism varied across cat breeds and the average minor allele frequency (MAF) of all markers across domestic cats was 0.21. Population structure analysis confirmed a Western to Eastern structural continuum of cat breeds. Genome-wide linkage disequilibrium ranged from 50\u20131,500 Kb for domestic cats and 750 Kb for European wildcats (Felis silvestris silvestris). Array use in trait association mapping was investigated under different modes of inheritance, selection and population sizes. The efficient array design and cat genotype dataset continues to advance the understanding of cat breeds and will support monogenic health studies across feline breeds and populations

Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. METHODS: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. FINDINGS: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. INTERPRETATION: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

Harmonic Analysis of Three Phase AC Voltage Regulators Using Thyristor - Diode Switches

Based upon numerical evaluation of Fourier coefficients, complete harmonic analysis is carried out for various three phase, AC thyrode voltage regulators. Various quantities of interest are computed and presented in the form of normalized curves for balanced R-L loads of different power factors. It is shown that the line controlled circuits offer the best overall performance and are superior in performance than the conventionally used thyristor voltage controllers

Harmonic Analysis of Three Phase AC Voltage Regulators Using Thyristor - Diode Switches

Based upon numerical evaluation of Fourier coefficients, complete harmonic analysis is carried out for various three phase, AC thyrode voltage regulators. Various quantities of interest are computed and presented in the form of normalized curves for balanced R-L loads of different power factors. It is shown that the line controlled circuits offer the best overall performance and are superior in performance than the conventionally used thyristor voltage controllers

Attenuation and EMI Frequency Spectrum for Distribution Lines

Corona and gap discharges occur at discrete points on distribution lines. Such discharges may produce electromagnetic interference (EMI) to the communication and control systems operating near such lines. Due to the discrete nature of distribution lines EMI sources, the total EMI produced by them is strongly influenced by the attenuation characteristics of the line. This paper discusses the factors which can influence the attenuation characteristics of distribution lines. Attenuation values are calculated for a typical three phase distribution line for different values of frequency, earth resistivity, conductor size, inter-conductor spacing, height and ground wire arrangement. The resulting values are presented in the form of empirical equations. Using such attenuation values, the relationship between the injected and measured noise is discussed for isolated as well as uniformly distributed noise sources. It is shown that unlike transmission lines, the distribution lines EMI may exhibit a variety of EMI frequency spectra depending upon the lines and soil parameters, type of noise source, as well as location of measurement point with respect to the noise source

STATISTICAL VARIATION OF DC CORONA PULSE AMPLITUDES IN POINT-TO-PLANE AIR GAPS.

Using a multichannel analyzer, statistical variations of corona pulse amplitudes are studied for positive and negative dc corona in point-to-plane air gaps. It is shown that, generally, pulse amplitudes follow a Gaussian type of probability distribution. Exceptions to this behavior are observed near the corona onset level, near the pulse-to-glow transition level, or in less nonuniform field gaps. The corona pulse amplitudes are reasonably reproducible for positive coronas, whereas for negative coronas, the pulse amplitudes are very sensitive to the applied voltage level and are less reproducible.IEEE

Impact of Sand/Dust Pollution on the Engineering Design Criteria of High Voltage Air Insulated Networks

Outdoor air insulated, high voltage transmission and distribution networks are frequently exposed to atmospheric pollution in the form of sand and dust storms which can affect the breakdown and prebreakdown characteristics and insulation performance of air gaps. This paper summarizes the findingks of an extensive study carried out to determine the effect of sand/dust contamination on the high voltage impulse breakdown characteristics of different types of air gaps. Analysis of the results of this study highlight the influence of airborne and surface adhering sand/dust contamination on the engineering design criteria to specify clearances of overhead lines and station equipment, design and performance of protective rod gaps and the accuracy of high voltage measurements using sphere gaps

Impact of Sand/Dust Pollution on the Engineering Design Criteria of High Voltage Air Insulated Networks

Outdoor air insulated, high voltage transmission and distribution networks are frequently exposed to atmospheric pollution in the form of sand and dust storms which can affect the breakdown and prebreakdown characteristics and insulation performance of air gaps. This paper summarizes the findingks of an extensive study carried out to determine the effect of sand/dust contamination on the high voltage impulse breakdown characteristics of different types of air gaps. Analysis of the results of this study highlight the influence of airborne and surface adhering sand/dust contamination on the engineering design criteria to specify clearances of overhead lines and station equipment, design and performance of protective rod gaps and the accuracy of high voltage measurements using sphere gaps