Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Dwivedi, B." wg kryterium: Autor


Wyświetlanie 1-7 z 7
Tytuł:
Development of Techno-Economical Objective Function for Supercapacitors Energy Storage System Implemented in Distribution System
Autorzy:
Sahay, K.
Dwivedi, B.
Powiązania:
https://bibliotekanauki.pl/articles/262799.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
supercapacitors energy storage system (SCESS)
net present value (NPV)
supercapacitor capital Cost Csccapital)
specific cost of energy capacity of supercapacitors (Cw)
specific cost of capacitance SCSS(CSc)
subscribed demand (Dsub)
Opis:
The development and advancement in storage technologies and custom power devices technologies are making the application of supercapacitors energy storage system a potentially viable solution for modern power distribution system application, permitting the system to be operated in more flexible and controllable manner. The supercapacitors energy storage system considered is supposed primarily for limiting the monthly subscribed demand levels, energy cost saving, for supply of energy in case of instantaneous need and long duration back up purpose. This paper presents the development of techno-economical multi-objective function for SCESS implemented in distribution system considering the constraints and their impact on optimization of net present value.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 2; 29-33
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and Analysis of Supercapacitors Energy Storage System for Energy Stabilization of Distribution Network
Autorzy:
Sahay, K.
Dwivedi, B.
Powiązania:
https://bibliotekanauki.pl/articles/262679.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
Power Distribution Network
Supercapacitors Energy Storage System
SCESS
energy stabilization
back up time
Equivalent Series Resistance
ESR
Equivalent Parallel Resistance
EPR
Opis:
Supercapacitors are the devices which can be store significant amounts of energy and quickly release it, their main application is for short term power compensation application where they can release a large amount of energy quickly and then can he recharged with smaller current. In this paper the use of Supercapacitors bank is explored for energy stabilisation and maintaining the voltage profile of the distribution system at the load point. The proposed supercapacitor bank is designed to improve the voltage profile of a distribution system by supplying the energy in case of demand and recharging the Supercapacitors bank in valley period. The designed bank is of 50 k\Vh{180 MJ) of energy, 440 V voltages and peak power of 30 kVV capacities for supply of energy in case of instantaneous need. The result shows that the SCESS can supply the instantaneous power for the back up the loads even though the voltage may drop up to 100 V; this SCESS can back up the load from 1.60-9.9974 hours depending upon the power demand while maintaining the minimum discharge voltage ratio and availability of useful energy.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 1; 25-32
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vector Controlled Induction Motor Drive Using Genetic Algorithm Tuned PI Speed Controller
Autorzy:
Dey, A.
Singh, B.
Dwivedi, B.
Chandra, D.
Powiązania:
https://bibliotekanauki.pl/articles/262627.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
genetic algorithm
vector control
tuning of PI
Ziegler Nichols Tuning Method
Opis:
In (his paper, timing and optimization of the proportional and integral (PI) gains of speed controller is achieved using Genetic Algorithm (GA) for improving the performance of the induction motor drive because higher the quality of the controller lesser is the ripples produced in the torque and speed responses. The developed GA program has multi-objective minimization functions. The optimized values of PI gains are incorporated in vector controlled induction motor model for performance analysis during sudden disturbances like speed reversal, load application and load removal. GA tuning method outstandingly surpasses the conventional and most widely used Ztegler Nichols Tuning method. GA tuned PI controller reduces the peak overshoot almost by 60% and quickly brings the system to steady state value. The simulated results obtained from GA tuned PI controller can be realized and validated through experimental results in future work.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2009, 15, 1; 3-8
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new closed loop speed control strategy for a vector controlled three-phase induction motor drive
Autorzy:
Tripathi, A.
Dey, A.
Dwivedi, B.
Singh, B.
Chandra, D.
Powiązania:
https://bibliotekanauki.pl/articles/262777.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
space vector modulation
VSI
induction motor model
transients
steady state value
Opis:
This paper presents a completely mathematical equations based model on control of torque and speed of a three-phase indirect vector controlled VSI fed cage induction motor drive that is controlled through the space vector modulated method. This enables a wide range of acceptability of the model for various values of load and for various types and ratings of induction motors. The uniqueness of the model lies in the fact that the deviations in the torque and speed on sudden application of reference step change in speed values are minimum i.e. when any sudden change in the speed reference is desired, the speed and torque waveforms reveal that the time taken in coming back to their final steady state values is very less and the motor overcomes the perturbation with negligible transients. The same is verified through the simulated results.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 1; 67-72
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved model of a three phase induction motor incorporating the parameter variations
Autorzy:
Dey, A.
Tripathi, A.
Singh, B.
Dwivedi, B.
Chandra, D.
Powiązania:
https://bibliotekanauki.pl/articles/262793.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
mathematical modeling
transient model
parameter variations
Opis:
A great deal of work is being done on the betterment of control through simulation of the electric drives used for various high-power purposes. The authenticity of the simulated results is based on the accurate modeling of the various parts of the electric drive system. Three–phase Induction motors form an extremely important part of the modern day electric drive system and their usage is continuously on a rise owing to their inherent properties of ruggedness, minimum maintenance requirements and continually increasing efficiencies. Usually the three-phase Induction motor model used in various research works does not incorporate stator and rotor core losses, stator and rotor stray load losses and magnetizing saturation and rotor conductor skin effects. The present paper aims at developing a threephase Induction motor model taking the above losses and effects into account. The dynamic linking of the model to a thermal model considering the temperature dependent resistive elements is an added feature. The motor model described in this paper is the extension of the conventional 2-phase lumped-parameter induction motor model. The biggest advantage is that the model is user-programmable in MA TLAB environment and can be used for system level transient studies. The simulation results of the developed model, with various parameter variations taken into account and subjected to sudden changes in load, show better torque and speed performances of the motor both in steady state and dynamic conditions.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 1; 73-78
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of organic inputs on strength and stability of soil aggregates under rice-wheat rotation
Autorzy:
Das, B.
Chakraborty, D.
Singh, V.K.
Aggarwal, P.
Singh, R.
Dwivedi, B.S.
Powiązania:
https://bibliotekanauki.pl/articles/25472.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
tensile strength
stability
soil aggregate
rice
wheat
cereal crop rotation
Opis:
The study aims to elucidate the impact of organic inputs on strength and structural stability of aggregates in a sandy loam soil. Tensile strength, friability and water stability of aggregates, and the carbon contents in bulk soil and in large macro (>2 mm), small macro (0.25-2 mm), micro (0.053-0.25 mm) and silt+clay size (<0.053) aggregates were evaluated in soils from a long-term experiment with rice-wheat rotation at Modipuram, India, with different sources and amounts of organic C inputs as partial substitution of N fertilizer. Addition of organic substrates significantly improved soil organic C contents, but the type and source of inputs had different impacts. Tensile strength of aggregates decreased and friability increased through organic inputs, with a maximum effect under green gram residue (rice)-farmyard manure (wheat) substitution. Higher macroaggregates in the crop residue- and farmyard manure-treated soils resulted in a higher aggregate mean weight diameter, which also had higher soil organic C contents. The bulk soil organic C had a strong relation with the mean weight diameter of aggregates, but the soil organic C content in all aggregate fractions was not necessarily effective for aggregate stability. The soil organic C content in large macroaggregates (2-8 mm) had a significant positive effect on aggregate stability, although a reverse effect was observed for aggregates <0.25 mm. Partial substitution of nitrogen by organic substrates improved aggregate properties and the soil organic C content in bulk soil and aggregate fractions, although the relative effect varied with the source and amount of the organic inputs.
Źródło:
International Agrophysics; 2014, 28, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multinomial Logistic Regression Approach For The Evaluation Of Binary Diagnostic Test In Medical Research
Autorzy:
Dwivedi, Alok Kumar
Mallawaarachchi, Indika
Figueroa-Casas, Juan B.
Powiązania:
https://bibliotekanauki.pl/articles/465774.pdf
Data publikacji:
2015
Wydawca:
Główny Urząd Statystyczny
Tematy:
multinomial logistic regression predictive values
sensitivity, specificity
acute appendicitis
pulmonary abnormalities
medical diagnostic test
Opis:
Evaluating the effect of variables on diagnostic measures (sensitivity, specificity, positive, and negative predictive values) is often of interest to clinical researchers. Logistic regression (LR) models can be used to predict diagnostic measures of a screening test. A marginal model framework using generalized estimating equation (GEE) with logit/log link can be used to compare the diagnostic measures between two or more screening tests. These individual modeling approaches to each diagnostic measure ignore the dependency among these measures that might affect the association of covariates with each diagnostic measure. The diagnostic measures are computed using joint distribution of screening test result and reference test result which generates a multinomial response data. Thus, multinomial logistic regression (MLR) is a more appropriate approach to modeling these diagnostic measures. In this study, the validity of LR and GEE approaches as compared to MLR model was assessed for modeling diagnostic measures. All methods provided unbiased estimates of diagnostic measures in the absence of any covariate. LR and GEE methods produced more biased estimates as compared to MLR approach especially for small sample size studies. No bias was obtained in predicting sensitivity measure using MLR method for one screening test. Our proposed MLR method is robust for modeling diagnostic measures of a screening test as opposed to LR method. MLR method and GEE method produced similar estimates of diagnostic measures for comparing two screening tests in large sample size studies. The proposed MLR model for diagnostic measures is simple, and available in common statistical software. Our study demonstrates that MLR method should be preferred as an alternative for modeling diagnostic measures.
Źródło:
Statistics in Transition new series; 2015, 16, 2; 203-222
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies