-
Dual Mode Controller Based Boost Converter Employing Soft Switching Techniques
J. Velmurugan,
R. M. Sekar,
Jojina anna varghese
Issue:
Volume 2, Issue 3, June 2013
Pages:
90-96
Received:
1 May 2013
Published:
10 June 2013
Abstract: This paper proposes a dual mode used to control a single phase soft switching boost power factor correction Converter (PFC) developed with a new active snubber circuit. The soft switched boost power factor correction converter has merits of less voltage and current stresses, improved efficiency and reduced switching losses. Thus the cost and complexity of the converter is reduced. The dual mode controller combines both continuous conduction mode (CCM) and critical conduction mode (CRM). The simulation results declare high efficiency and optimum power factor for wide range of varying loads.
Abstract: This paper proposes a dual mode used to control a single phase soft switching boost power factor correction Converter (PFC) developed with a new active snubber circuit. The soft switched boost power factor correction converter has merits of less voltage and current stresses, improved efficiency and reduced switching losses. Thus the cost and comple...
Show More
-
Modelling and Forecasting of One-dimensional Nonstationary Heat Transfer in Building Envelopes for Energy Efficiency Building
Semjen Kundas,
Elena Kresova
Issue:
Volume 2, Issue 3, June 2013
Pages:
97-103
Received:
10 March 2013
Published:
20 June 2013
Abstract: One-dimensional nonstationary heat transfer in three-layered building envelope is examined in this work. Therefore, initial and boundary conditions are examined. Possibility not only for modelling but for forecasting of heat transfer in capillary-porous structures of building envelopes is considered as well. For this purpose, time series analysis method was used. Standards for resistance of heat transfer in European countries and in Belarus are considered. Resistance to heat transfer of three-layer envelope where internal and exterior layers are precast layers and heat insulation is cellular polystyrene against heat insulation layer depth is examined as well.
Abstract: One-dimensional nonstationary heat transfer in three-layered building envelope is examined in this work. Therefore, initial and boundary conditions are examined. Possibility not only for modelling but for forecasting of heat transfer in capillary-porous structures of building envelopes is considered as well. For this purpose, time series analysis m...
Show More
-
Investigation of Double-Gap Cavity Generating-Amplifying Klystrons
Tatyana Remizova,
Valeriy Fedyaev,
Basil Yurkin
Issue:
Volume 2, Issue 3, June 2013
Pages:
104-108
Received:
14 May 2013
Published:
20 June 2013
Abstract: Based upon the discrete model of large particle flux investigated is the possibility of operation of a double-gap cavity resonator in the mode where the oscillation generating function is aligned with the function of velocity-modulating electrons in the phase ensuring further sufficient electron bunching. It is established that the required distribution of velocities is gained on the edge of the generation area with longest distance between gaps where both phase and amplitude conditions of self-excitement are met. Shown is the possibility of obtaining the highest efficiency at the expense of using a double-gap cavity resonator with wide gaps. Performed is the investigation of generating–amplifying klystrons of different configurations. Found are conditions of obtaining a maximum value of amplitude of the convection current first harmonic and a maximum value of the efficiency factor.
Abstract: Based upon the discrete model of large particle flux investigated is the possibility of operation of a double-gap cavity resonator in the mode where the oscillation generating function is aligned with the function of velocity-modulating electrons in the phase ensuring further sufficient electron bunching. It is established that the required distrib...
Show More
-
Correlation between Reliability and Weather Scenario: In Perspective of Bangladesh Power System
Shohana Rahman Deeba,
Nahid-Al- Masood
Issue:
Volume 2, Issue 3, June 2013
Pages:
109-112
Received:
30 May 2013
Published:
30 June 2013
Abstract: This paper presents the correlation between the reliability and the weather scenario of Bangladesh Power System (BPS). Reliability of the power system is one of the major features of power quality. The variation of electrical demand above its base value is its common characteristic. The weather dependent variation of demand, especially where the weather is severe in nature, requires a significant reserve margin to ensure an acceptable level of reliability of the generation system. In Bangladesh, a significant difference in demands of winter and summer is generated due to weather variation. As a result the utility has to ensure an additional seasonal generation reserve capacity to maintain an acceptable level of reliability. This paper determines the correlation between the weather variables, namely temperature and relative humidity, and the reliability of Bangladesh Electricity Network. It also investigates the additional generation requirement during summer season to maintain an acceptable reliability level.
Abstract: This paper presents the correlation between the reliability and the weather scenario of Bangladesh Power System (BPS). Reliability of the power system is one of the major features of power quality. The variation of electrical demand above its base value is its common characteristic. The weather dependent variation of demand, especially where the we...
Show More
-
Oxide-Metal Core Is Possible Transition to the Metal Fuel Core for Fast Reactors of the BN-Type
Issue:
Volume 2, Issue 3, June 2013
Pages:
113-120
Received:
17 May 2013
Published:
10 July 2013
Abstract: The article deals with the initial requirements for metal fuel elements and commercial reactors using this type of elements: high smear density of fuel, high technological effectiveness of fuel, fuel column and fuel elements; interchangeability of metal fuel elements and oxide fuel elements; achievement of fuel breeding ratio of the core BRC ~1.0; prolongation of refuelling cycle up to Tc~11 months. The article presents content and results of examinations of radiation-thermal effects in U fuel column elements and UPu fuel column elements: irradiation of breeding and fuel elements in the BOR-60 and BN-350 reactors; research of macroeffects of radiation growth, radiation swelling, fuel-cladding chemical interaction. Applicability of the obtained results for developing advanced BN-reactors with heterogeneous cores of various types was discussed: with by FA heterogenization of the core (BFAH); intra FA heterogenization of the core (IFAH); intra fuel element heterogenization (IFEH).
Abstract: The article deals with the initial requirements for metal fuel elements and commercial reactors using this type of elements: high smear density of fuel, high technological effectiveness of fuel, fuel column and fuel elements; interchangeability of metal fuel elements and oxide fuel elements; achievement of fuel breeding ratio of the core BRC ~1.0; ...
Show More
-
Protective Relaying Scheme of Distributed Generation Connected Radial Distribution System
Murali Matcha,
Sharath Kumar Papani,
Vijetha Killamsetti
Issue:
Volume 2, Issue 3, June 2013
Pages:
121-127
Received:
16 June 2013
Published:
20 July 2013
Abstract: This paper discusses some aspects related to the connection of distributed generators to radial distribution systems, especially their impact on the protection coordination. Penetration of a DG into an existing distribution system has many impacts on the system, with the power system protection being one of the major issues. The relays in the power system have to be coordinated so as to avoid mal-operation and unnecessary outage of healthy part of the system. In this paper, Overcurrent relay coordination of simple radial industrial power plant is presented using NEPLAN Software. It presents the short circuit analysis of radial industrial power plant. This paper shows the star view of relays which is unique feature of NEPLAN for coordinating them correctly based upon recorded data of industrial distribution plant for calculating short circuit currents in industrial power system. Results obtained are verified by manual calculation.
Abstract: This paper discusses some aspects related to the connection of distributed generators to radial distribution systems, especially their impact on the protection coordination. Penetration of a DG into an existing distribution system has many impacts on the system, with the power system protection being one of the major issues. The relays in the power...
Show More
-
Mathematical Modelling, Finite Element Simulation and Experimental Validation of Biogas-digester Slurry Temperature
Suresh Baral,
Shiva P. Pudasaini,
Sanjay Nath Khanal,
Dil Bahadur Gurung
Issue:
Volume 2, Issue 3, June 2013
Pages:
128-135
Received:
8 July 2013
Published:
20 July 2013
Abstract: The present describes and simulates the temperature distribution of slurry by using the heat equation and appropriate boundary conditions and their numerical simulations with the Finite Element Method. This method is suitable to describe the temperature profile in Bio-digester and Bio-rectors for optimum biogas production. The Mathematical modeling of bio-digester helps us to understand the change in digester temperature with the change in the ambient temperature, internal heat generation, thermal conductivity and other physical and thermo-dynamical processes that govern the thermal system. Mathematical modeling can also be used to predict and estimate the physical and chemical parameters affecting the biogas production. The internal heat generation was estimated to be 1.2 W/m3.The Finite Element linear, quadratic solutions and exact solution was compared for the profile of temperature of the bio-digester slurry. The average temperature of bio-digester slurry was found to be 33.12 °C at its center. The thermal conductivity we have also found to be 0.69 W/ m °C. By using the finite element method to solve the mathematical modeling, the maximum slurry temperature was found to be 33.13 °C at its center. Furthermore, we have calculated the thermal conductivity in the biogas chamber from our measurement data. This thermal conductivity (k) 0.69 W/m °C was used in the exact solution of the physical model equation, linear and quadratic finite elements solutions. The temperature profiles of these three solutions virtually collapse to a single parabolic profile, which in term agreed very well with our measured data of the temperature profile.
Abstract: The present describes and simulates the temperature distribution of slurry by using the heat equation and appropriate boundary conditions and their numerical simulations with the Finite Element Method. This method is suitable to describe the temperature profile in Bio-digester and Bio-rectors for optimum biogas production. The Mathematical modeling...
Show More
-
Seasonal Peak Electricity Demand Characteristics: Japan Case Study
Yusri Syam Akil,
Hajime Miyauchi
Issue:
Volume 2, Issue 3, June 2013
Pages:
136-142
Received:
7 June 2013
Published:
30 July 2013
Abstract: Because of the need to keep balancing between electricity supply and demand continuously, a demand analysis is necessary as it can provide essential information to manage operation of a power system. This study presents a seasonal peak demand characteristics investigation for commercial area in Japan by developing hourly demand regression models for each season. Meteorological parameters and existing holidays are considered as demand drivers. Many standard statistical tests are applied to the models. From results, typical forms of link between commercial demand and key drivers at peak hours (daytime and evening) in each season can be revealed through the models. Knowing more detail characteristic of a demand particularly during high load hours can help utilities to maintain expected optimal operation of power systems and service to consumers all the time.
Abstract: Because of the need to keep balancing between electricity supply and demand continuously, a demand analysis is necessary as it can provide essential information to manage operation of a power system. This study presents a seasonal peak demand characteristics investigation for commercial area in Japan by developing hourly demand regression models fo...
Show More
