318 research outputs found
Intelligent cascaded adaptive neuro fuzzy interface system controller fed KY converter for hybrid energy based microgrid applications
Purpose. This article proposes a new control strategy for KY (DC-DC voltage step up) converter. The proposed hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Renewable energy sources have recently acquired immense significance as a result of rising demand for electricity, rapid fossil fuel exhaustion and the threat of global warming. However, due to their inherent intermittency, these sources offer low system reliability. So, a hybrid energy system that encompasses wind/photovoltaic/battery is implemented in order to obtain a stable and reliable microgrid. Both solar and wind energy is easily accessible with huge untapped potential and together they account for more than 60 % of yearly net new electricity generation capacity additions around the world. Novelty. A KY converter is adopted here for enhancing the output of the photovoltaic system and its operation is controlled with the help of a cascaded an adaptive neuro fuzzy interface system controller. Originality. Increase of the overall system stability and reliability using hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Practical value. A proportional integral controller is used in the doubly fed induction generator based wind energy conversion system for controlling the operation of the pulse width modulation rectifier in order to deliver a controlled DC output voltage. A battery energy storage system, which uses a battery converter to be connected to the DC link, stores the excess power generated from the renewable energy sources. Based on the battery’s state of charge, its charging and discharging operation is controlled using a proportional integral controller. The controlled DC link voltage is fed to the three phase voltage source inverter for effective DC to AC voltage conversion. The inverter is connected to the three phase grid via an LC filter for effective harmonics mitigation. A proportional integral controller is used for achieving effective grid voltage synchronization. Results. The proposed model is simulated using MATLAB/Simulink, and from the obtained outcomes, it is noted that the cascaded adaptive neuro fuzzy interface system controller assisted KY converter is capable of maintaining the stable operation of the microgrid with an excellent efficiency of 93 %.Мета. У цій статті пропонується нова стратегія управління перетворювачем KY (підвищення напруги постійного струму). Пропонована гібридна енергетична система, що живиться перетворювачем KY, використовується разом із контролером системи адаптивного нейро-нечіткого інтерфейсу. Відновлювані джерела енергії останнім часом набули величезного значення внаслідок зростання попиту на електроенергію, швидкого виснаження викопного палива та загрози глобального потепління. Однак через властиву їм уривчастість ці джерела забезпечують низьку надійність системи. Таким чином, гібридна енергетична система, що включає енергію вітру/фотоелектричних елементів/акумулятору, реалізована для отримання стабільної і надійної мікромережі. Як сонячна, так і вітрова енергія доступні з величезним невикористаним потенціалом, і разом вони забезпечують понад 60 % щорічного чистого приросту нових потужностей з виробництва електроенергії в усьому світі. Новизна. Перетворювач KY використовується тут для підвищення вихідної потужності фотоелектричної системи, і його робота керується за допомогою каскадного контролера системи з адаптивним нейро-нечітким інтерфейсом. Оригінальність. Підвищення загальної стабільності та надійності системи за допомогою гібридної енергетичної системи, що живиться перетворювачем KY і використовується разом з контролером системи з адаптивним нейро-нечітким інтерфейсом. Практична цінність. Пропорційний інтегральний контролер використовується в системі перетворення енергії вітру на основі асинхронного генератора з подвійним живленням для управління випрямлячою роботою з широтно-імпульсною модуляцією для забезпечення регульованої вихідної напруги постійного струму. Акумуляторна система накопичення енергії, в якій використовується акумуляторний перетворювач для підключення до кола постійного струму, зберігає надмірну потужність, що виробляється з відновлюваних джерел енергії. Залежно від стану заряду акумулятора, процес його зарядки і розрядки контролюється за допомогою пропорційного інтегрального контролера. Керована напруга кола постійного струму подається на трифазний інвертор джерела напруги для ефективного перетворення постійної напруги змінну. Інвертор підключений до трифазної мережі через LC-фільтр для ефективного придушення гармонік. Пропорційний інтегральний регулятор використовується для досягнення ефективної синхронізації напруги мережі. Результати. Запропонована модель змодельована з використанням MATLAB/Simulink, і з отриманих результатів випливає, що каскадний адаптивний нейро-нечіткий інтерфейс із системним контролером та перетворювачем KY здатний підтримувати стабільну роботу мікромережі з чудовим ККД 93 %
Improvement of power quality in grid-connected hybrid system with power monitoring and control based on internet of things approach
Purpose. This article proposes a new control monitoring grid connected hybrid system. The proposed system, improvement of power quality is achieved with internet of things power monitoring approach in solar photovoltaic grid system network. The novelty of the proposed work consists in presenting solar power monitoring and power control based internet of things algorithm, to generate DC voltage and maintain the constant voltage for grid connected hybrid system. Methods. The proposed algorithm which provides sophisticated and cost-effective solution for measuring the fault and as maximum power point tracking assures controlled output and supports the extraction of complete power from the photovoltaic panel. The objective of the work is to monitor and control the grid statistics for reliable and efficient delivery of power to a hybrid power generation system. Internet of things is regarded as a network comprising of electronic embedded devices, physical objects, network connections, and sensors enabling the sensing, analysis, and exchange of data. The proposed control technique strategy is validated using MATLAB/Simulink software and real time implementation to analysis the working performances. Results. The results obtained show that the power quality issue, the proposed system to overcome through monitoring of fault solar panel and improving of power quality. The obtained output from the hybrid system is fed to the grid through a 3ϕ voltage source inverter is more reliable and maintained power quality. The power obtained from the entire hybrid setup is measured by the sensor present in the internet of things-based module. In addition to that, the photovoltaic voltage is improved by a boost converter and optimum reliability is obtained with the adoption of the perturb & observe approach. The challenges in the integration of internet of things – smart grid must be overcome for the network to function efficiently. Originality. Compensation of power quality issues, grid stability and harmonic reduction in distribution network by using photovoltaic based internet of things approach is utilized along with sensor controller. Practical value. The work concerns a network comprising of electronic embedded devices, physical objects, network connections, and sensors enabling the sensing, analysis, and exchange of data. In this paper, internet of things sensors are installed in various stages of the smart grid in a hybrid photovoltaic –wind system. It tracks and manages network statistics for safe and efficient power delivery. The study is validated by the simulation results based on MATLAB/Simulink software and real time implementation.Мета. У статті пропонується нова гібридна система управління моніторингом, підключена до мережі. У запропонованій системі покращення якості електроенергії досягається за допомогою підходу Інтернету речей до моніторингу потужності у мережі сонячної фотоелектричної мережі. Новизна запропонованої роботи полягає у поданні алгоритму моніторингу сонячної енергії та управління потужністю, заснованого на Інтернеті речей, для генерації напруги постійного струму та підтримки постійної напруги для гібридної системи, підключеної до мережі. Методи. Пропонований алгоритм, який забезпечує складне та економічне рішення для вимірювання несправності та відстеження точки максимальної потужності, забезпечує контрольований вихід та підтримує вилучення повної потужності з фотоелектричної панелі. Метою роботи є моніторинг та управління статистикою мережі для надійної та ефективної подачі електроенергії до гібридної системи виробництва електроенергії. Інтернет речей розглядається як мережа, що складається з електронних вбудованих пристроїв, фізичних об'єктів, мережевих підключень та датчиків, що дозволяють сприймати, аналізувати та обмінюватися даними. Запропонована стратегія методу управління перевіряється з використанням програмного забезпечення MATLAB/Simulink та реалізації у режимі реального часу для аналізу робочих характеристик. Результати показують, що запропонована система вирішує проблему якості електроенергії за рахунок моніторингу несправності сонячної панелі та покращення якості електроенергії. Отриманий вихід гібридної системи подається в мережу через інвертор джерела напруги 3ϕ, що є більш надійним і підтримує якість електроенергії. Потужність, отримана від усієї гібридної установки, вимірюється датчиком, що є присутнім у модулі на основі Інтернету речей. На додаток до цього фотогальванічна напруга покращується за допомогою перетворювача, що підвищує, а оптимальна надійність досягається за рахунок застосування підходу «збурюй і спостерігай». Щоб мережа функціонувала ефективно, необхідно вирішити проблеми інтеграції Інтернету речей – смарт-мереж. Оригінальність. Поряд із сенсорним контролером використовується компенсація проблем з якістю електроенергії, стабільністю мережі та зменшенням гармонік у розподільній мережі з використанням підходу до Інтернету речей на основі фотоелектричних систем. Практична цінність. Робота стосується мережі, що складається з електронних вбудованих пристроїв, фізичних об’єктів, мережевих підключень та датчиків, що дозволяють сприймати, аналізувати та обмінюватися даними. У цій статті датчики Інтернету речей встановлюються на різних етапах інтелектуальної мережі у гібридній фотоелектричній та вітровій системі. Він відстежує та керує мережевою статистикою для безпечної та ефективної подачі енергії. Дослідження підтверджено результатами моделювання, що базуються на програмному забезпеченні MATLAB/Simulink та реалізації в реальному часі.
ANCILLARY SERVICE REQUIREMENT BASED AUTOMATIC GENERATION CONTROL ASSESSMENT IN A DEREGULATED POWER SYSTEM WITH HES AND IPFC UNITS
This paper intends the evaluation measures for obtaining the Ancillary ServicesRequirement (ASR) indices stand on Automatic Generation Control (AGC) in a deregulated power system.Ancillary services are vital to support the transmission of electric power from vendor to user with the responsibility of control areas and transmitting utilities within those control areas to maintain steadfast operations of the interconnected power system under deregulated environment. In this swot, Proportional Integral Derivative with derivative Filter (PIDF) is projected for the AGC loop of a two-area thermal power system with reheat bicycle mix condensation turbine. The control constraints of the PIDF controller are optimized using the Big Bang Big Crunch (BBBC) algorithm.ASR keys are computed stranded on the dynamic response of the control input deviations and the mechanical power generation deviations of each area for dissimilar nature of possible transactions. These indices designate the ancillary service requirements and are required to improve the competence of the physical operation of the power system with the augmented transmission capacity in the network. An advanced application of Hydrogen Energy Storage (HES), when coordinated with the Interline Power Flow Controller (IPFC) for the development of AGC loop of a two-area thermal power system is also painstaking. Simulation reveals that the proposed PIDF controller tuned with BBBC algorithm perk up the dynamic output response of the test system. Moreover, it can also be pragmatic that the ASR Indices are computed for a two-area thermal power system with HES and IPFC units indicates that the new advanced control for a better restoration of the power system output responses and ensure enhanced ASR indices in order to afford the superior margin of steadiness
Intelligent cascaded adaptive neuro fuzzy interface system controller fed KY converter for hybrid energy based microgrid applications
Purpose. This article proposes a new control strategy for KY (DC-DC voltage step up) converter. The proposed hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Renewable energy sources have recently acquired immense significance as a result of rising demand for electricity, rapid fossil fuel exhaustion and the threat of global warming. However, due to their inherent intermittency, these sources offer low system reliability. So, a hybrid energy system that encompasses wind/photovoltaic/battery is implemented in order to obtain a stable and reliable microgrid. Both solar and wind energy is easily accessible with huge untapped potential and together they account for more than 60 % of yearly net new electricity generation capacity additions around the world. Novelty. A KY converter is adopted here for enhancing the output of the photovoltaic system and its operation is controlled with the help of a cascaded an adaptive neuro fuzzy interface system controller. Originality. Increase of the overall system stability and reliability using hybrid energy system fed KY converter is utilized along with adaptive neuro fuzzy interface system controller. Practical value. A proportional integral controller is used in the doubly fed induction generator based wind energy conversion system for controlling the operation of the pulse width modulation rectifier in order to deliver a controlled DC output voltage. A battery energy storage system, which uses a battery converter to be connected to the DC link, stores the excess power generated from the renewable energy sources. Based on the battery’s state of charge, its charging and discharging operation is controlled using a proportional integral controller. The controlled DC link voltage is fed to the three phase voltage source inverter for effective DC to AC voltage conversion. The inverter is connected to the three phase grid via an LC filter for effective harmonics mitigation. A proportional integral controller is used for achieving effective grid voltage synchronization. Results. The proposed model is simulated using MATLAB/Simulink, and from the obtained outcomes, it is noted that the cascaded adaptive neuro fuzzy interface system controller assisted KY converter is capable of maintaining the stable operation of the microgrid with an excellent efficiency of 93 %
OPTIMAL ALLOCATION OF TCSC DEVICES FOR THE ENHANCEMENT OF ATC IN DEREGULATED POWER SYSTEM USING FLOWER POLLINATION ALGORITHM
This paper proposes a best possible distribution of Thyristor Controlled Series Compensator (TCSC) to progress the Available Transfer Capability (ATC) of power transactions between sources and sink areas in the deregulated power system. The principle of TCSC device is to balance the inductive voltage drop in the line by an introduced capacitive voltage or in other words to alleviate the effective reactance of the transmission line to improve ATC in the network. The objective of the optimization is to find the preeminent location and parameters of TCSC devices by means of Flower Pollination Algorithm (FPA) for maximizing ATC and minimizing power losses and installation cost of TCSC device. The estimate of ATC using AC Power Transfer Distribution Factors (ACPTDF) based on the Newton Raphson power flow technique. The ACPTDFs are the consequent using sensitivity based approach for the system intact case and utilized to check the line flow limits during ATC fortitude. The efficacy of the proposed method is demonstrated using an IEEE-30 bus test system for the evaluation of ATC in normal and line outage contingencies conditions for the preferred bilateral, multilateral and area wise transactions. The simulation outcome illustrates that the introduction of TCSC devices in an accurate location could increase ATC, fall in total losses and advance the line congestion as compared to the system without TCSC devices
RT-2 Detection of Quasi-Periodic Pulsations in the 2009 July 5 Solar Hard X-ray Flare
We present the results of an analysis of hard X-ray observations of the C2.7
solar flare detected by the RT-2 Experiment onboard the Coronas - Photon
satellite. We detect hard X-ray pulsations at periods of ~12 s and ~15 s. We
find a marginal evidence for a decrease in period with time. We have augmented
these results using the publicly available data from the RHESSI satellite. We
present a spectral analysis and measure the spectral parameters.Comment: 12 pages, 8 figures and 3 tables, accepted for publication in The
Astrophysical Journa
A rationale for continuing mass antibiotic distributions for trachoma
BACKGROUND: The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. METHODS: We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. RESULTS: Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. CONCLUSION: Local elimination from a community is theoretically possible, even in the most severely infected communities. However, elimination from larger areas may require repeated biannual treatments and prevention of re-introduction from outside to treated areas
Reduction and Return of Infectious Trachoma in Severely Affected Communities in Ethiopia
Trachoma is one of the leading causes of blindness in the developing world. The World Health Organization has a multi-pronged approach to controlling the ocular chlamydial infection that causes the disease, including distributing antibiotics to entire communities. Even a single community treatment dramatically reduces the prevalence of the infection. Unfortunately, infection returns back into communities after treatment, at least in severely affected areas such as rural Ethiopia. Here, we assess whether additional scheduled treatments in 16 communities in the Gurage area of Ethiopia further reduce infection, and whether the disease returns after distributions are stopped. In communities with the highest levels of trachoma ever studied, we find that repeated mass oral azithromycin distributions gradually reduce the prevalence of trachoma infection in a community, as long as these treatments are given frequently enough and to enough people in the community. Unfortunately, infection returns into the communities after the last treatment. Sustainable changes or complete local elimination of infection will be necessary to stop the return of ocular chlamydial in communities with very high prevalence of the disease
Genome-wide association study for type 2 diabetes in Indians identifies a new susceptibility locus at 2q21
Meta-AnalysisThis is the final version of the article. Available from the American Diabetes Association via the DOI in this record.Indians undergoing socioeconomic and lifestyle transitions will be maximally affected by epidemic of type 2 diabetes (T2D). We conducted a two-stage genome-wide association study of T2D in 12,535 Indians, a less explored but high-risk group. We identified a new type 2 diabetes-associated locus at 2q21, with the lead signal being rs6723108 (odds ratio 1.31; P = 3.32 × 10⁻⁹). Imputation analysis refined the signal to rs998451 (odds ratio 1.56; P = 6.3 × 10⁻¹²) within TMEM163 that encodes a probable vesicular transporter in nerve terminals. TMEM163 variants also showed association with decreased fasting plasma insulin and homeostatic model assessment of insulin resistance, indicating a plausible effect through impaired insulin secretion. The 2q21 region also harbors RAB3GAP1 and ACMSD; those are involved in neurologic disorders. Forty-nine of 56 previously reported signals showed consistency in direction with similar effect sizes in Indians and previous studies, and 25 of them were also associated (P < 0.05). Known loci and the newly identified 2q21 locus altogether explained 7.65% variance in the risk of T2D in Indians. Our study suggests that common susceptibility variants for T2D are largely the same across populations, but also reveals a population-specific locus and provides further insights into genetic architecture and etiology of T2D.The major funding for this work comes from Council for Scientific and Industrial Research, Government of India, in the form of the grant “Diabetes mellitus—New drug discovery R&D, molecular mechanisms, and genetic and epidemiological factors” (NWP0032-19). R.T. received a postdoctoral fellowship from the Fogarty International Center and the Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health (D43-HD-065249)
Detection of GRB 090618 with RT-2 Experiment Onboard the Coronas-Photon Satellite
We present the results of an analysis of the prompt gamma-ray emission from
GRB 090618 using the RT-2 Experiment onboard the Coronas-Photon satellite. GRB
090618 shows multiple peaks and a detailed study of the temporal structure as a
function of energy is carried out. As the GRB was incident at an angle of 77
degree to the detector axis, we have generated appropriate response functions
of the detectors to derive the spectrum of this GRB. We have augmented these
results using the publicly available data from the Swift BAT detector and show
that a combined spectral analysis can measure the spectral parameters quite
accurately. We also attempt a spectral and timing analysis of individual peaks
and find evidence for a systematic change in the pulse emission characteristics
for the successive pulses. In particular, we find that the peak energy of the
spectrum, E_p, is found to monotonically decrease with time, for the successive
pulses of this GRB.Comment: 12 pages, 6 figures, 3 tables, Accepted for publication in The
Astrophysical Journa
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