Paper Title, Authors, Abstract (Issue 1, Volume 2, 2008)

Pages

Extended Supplementary Controller of UPFC to Improve Damping Inter-Area Oscillations Considering Inertia Coefficient
A. Kazemi, M. R. Shadmesgaran

Abstract: This paper proposed a new control strategy of a unified power flow controller (UPFC) to improve damping inter-area oscillations. Since active loads are continually changed in power systems, considering effects of active load variation on damping of power system oscillations between interconnected areas is very important for the system secure operation. In this paper it is shown that, increasing of active loads in load buses cause increasing the electromechanical oscillations. Also this paper show that increasing inertia coefficient of large generators causes increase electromechanical oscillations in power systems. Simulation results on a two-area 4-generator interconnected system show that the suggested UPFC control strategy can improve damping significantly.
 

A New Methodology for Distribution System Feeder Reconfiguration
S. Prabhakar Karthikeyan, Jacob Raglend, Pallerlamudi Pratyusha, D. P. Kothari

Abstract: Distribution System Automation (DSA) is being carried out very seriously world over to enhance the reliability of the system and to minimize the huge losses that are occurring in the Distribution System. Feeder Reconfiguration (FR) is an important sub-problem of the overall distribution system automation process. Basic concept of feeder reconfiguration is to arrive at the best set of sectionalizing switches to be opened for a given set of tie switch such that the system performance is enhanced. In this paper a novel criterion is proposed based on the slope of the curve between the feeder losses verses receiving end voltage. Application of this criterion results in the most minimal loss configuration for any given loading condition. An existing switching indices criterion and switching algorithm criterion has been considered and the results are compared with that of the proposed slope criterion which results in the most minimal loss configuration. General MATLAB programs are developed to these criterions to obtain the best switching option.
 

    Paper Title, Authors, Abstract (Issue 2, Volume 2, 2008)

Pages

Performance of a Grid-Interactive Rooftop Photovoltaic System with Battery Storage
S. Bhattacharjee, D. Debbarma, S. Sharma, A. Das

Abstract: In North East India, there is severe power shortage and associated power quality problems; the quality of grid supply in most of the places is characterized by large voltage and frequency fluctuations, scheduled and unscheduled power cuts and load restrictions. Load shedding in many cities in North East India due to power shortage and faults is a major problem for which there is no immediate remedy in the near future since the gap between the power demand and supply is increasing every year. This led to rapid usage of stand-by petrol or diesel generator sets and conventional battery inverter sets in both urban and rural areas. Shopkeepers, house owners and offices commonly use 1-5 kW fuel generators when utility exercises load shedding. But this region is rich in sun shine and solar energy is available all over the year at free of cost. The paper analyses the performance of grid-interactive photovoltaic system with storage facility for this region. The system is installed at Tripura University campus. Online monitoring is carried out and real time data have been collected to study the feasibility of grid-interactive PV system penetration in this region particularly for the state Tripura. This paper presents the response of the various components of the system with available solar energy input.
 

The Offline Effect Assessment System of Design Factors on Search for High Risk Events of Power Systems
Tetsushi Miki

Abstract: Power systems become large and complex, so the occurrence rates of a great deal of energy loss caused by faults become high. In this situation, the development of the efficient search method for high risk events of power systems is strongly required. Risk is defined as the product of energy loss and its occurrence rate, considering that the goal of power systems is the stable supply of power. This paper presents the developed offline system which can assess accurately and efficiently effects of design factors on search for high risk events caused by loss of transient stability of power systems. Being focused on control systems, it was applied to the model system composed of 3 generators and 9 buses. The results of application have clarified its effectiveness.
 

    Paper Title, Authors, Abstract (Issue 3, Volume 2, 2008)

Pages

Fuel of Diesel-Olive Seed Oil Mixtures
Charalampos Arapatsakos, Dimitrios Christoforidis, Anastasios Karkanis, Konstantinos Mitroulas

Abstract: Some of the consequences of crude oil dependence are the increasing price of crude oil, the important changes in oil market, the finite of reserves as well as the environmental pollution. Therefore, there is a big need to produce appropriate fuels, which will have minimal environmental and social degradation. This led to the revaluation of the importance of the rural and forestall factor as a renewable resources supplier. This essay testes the use of diesel-olive seed oil mixtures in diesel four-stroke engine. The mixtures used are the following: diesel-5% olive seed oil, diesel-10% olive seed oil, diesel-20% olive seed oil, diesel-30% olive seed oil, diesel-40% olive seed oil, diesel-50% olive seed oil. For those mixtures the gas emissions of carbon monoxide (CO), hydrocarbons (HC), nitrogen monoxide (NO) are being measured and the fuel consumption is also examined.
 

Fuel Mixtures of Diesel-Maize Oil
Charalampos Arapatsakos, Dimitrios Christoforidis, Georgios Sarantitis, Dimitrios Giannopoulos

Abstract: Petroleum – based fuels is a finite resource that is rapidly depleting. Consequently, petroleum reserves are not sufficient enough to last many years. Considering also the fact that petroleum – based fuels, can cause many environmental problems, imbalance of trade, high oil process etc, it becomes necessary the development of alternative fuel sources. At this paper will be examined the use of diesel-maize oil mixtures in diesel four-stroke engine. The mixtures used are the following: diesel-5% maize oil, diesel-10% maize oil, diesel-20% maize oil oil, diesel-30% maize oil, diesel-40% maize oil, diesel-50% maize oil. For those mixtures the gas emissions of carbon monoxide (CO), hydrocarbons (HC), nitrogen monoxide (NO) are being measured and the fuel consumption is also examined.
 

    Paper Title, Authors, Abstract (Issue 4, Volume 2, 2008)

Pages

Electromagnetic and Thermal Model Parameters
Marius-Constantin O. S. Popescu, Nikos E. Mastorakis, Cornelia A. Bulucea, Liliana N. Perescu-Popescu

Abstract: The study of thermal model structural parameters is performed in this paper. Electromagnetic parameters are derived with recourse of electromagnetic similitude laws, and theoretical results are validated with data from transformer manufacturers. Different methodologies to estimate thermal parameters with data from standardised heat-run tests are compared.
 

Ship Propulsion Plant Transient Response Investigation using a Mean Value Engine Model
Gerasimos P. Theotokatos

Abstract: In the present paper, the transient response of a merchant ship propulsion plant is investigated using a model implemented in the computational environment MATLAB/Simulink. The main engine of the vessel, which is considered to be of the twostroke marine Diesel type, is modeled by the means of a quasi steady cycle mean value approach. According to that, two non-linear first order differential equations, which are derived by applying the angular momentum conservation in engine crankshaft and turbocharger shaft, are used for the calculation of engine crankshaft and turbocharger shaft rotational speeds. The other engine operating parameters are calculated after the solution of a non-linear algebraic system of three equations corresponding to the mass and energy balances in the engine components. In order to calculate the propeller thrust and torque, the polynomials for the propellers of the Wageningen B type are used. In addition, the ship velocity and the movement along its longitudinal axis are also calculated using the differential equation describing the ship surge dynamics. The engine model is validated against previously published experimental data. Then, the simulation of merchant ship propulsion plant under various operating conditions is performed and the derived results are presented and discussed.
 

A Procedure for Assessment of Maximal Electromagnetic Field Values from Urban Power Substation
Nino Bozic, Niksa Kovac, Mario Cvetkovic

Abstract: The paper deals with an assessment procedure of the maximal electromagnetic field values related to urban power substation. Assessment of maximal electromagnetic field values from urban power substations are of great interest for both power utilities and the general public. This work provides an assessment procedure for the maximal magnetic field values from urban power substations based on a limited number of measured values, thus reducing the required measurement effort. The technique used in this work comprises the multiquadric approximation of a field quantity obtained using the discrete measured data set. The approximation sufficiently handles multidimensional multiextreme functions by interpolating their discrete values accurately. Subsequently, the maximal value of a field quantity is evaluated by minimizing the negative multiquadric approximation via a stochastic optimization method - differential evolution. Therefore, the implemented procedure provides the maximal value assessment on the basis of a limited number of measured values, thus reducing the experimental cost. Moreover, measurement results of ELF magnetic fields produced by urban power substation are analysed for better understanding of the influence of various field sources.