Volume 3, Issue 6, June 2012

Comparison of the Performance of the VSI-Fed Adjustable-Speed Drives Under Balanced and Unbalanced Voltage Sag Conditions

M. Abou El-Azaim Mahdy, A. F. Zobaa, Senior Member, IEEE, and M. M. Abdel Aziz, Senior Member, IEEE

Middle Egypt Co. for Electricity Distribution, Benisuef, Egypt
Electrical Power & Machines Department, Faculty of Engineering, Cairo University, Giza, 12613, Egypt

Abstract– Adjustable-Speed Drives are one of the most sensitive equipments to voltage sags. Even though there have been numerous studies addressing Adjustable-Speed Drives effects on power systems, models for predicting the effect of the source voltage sags or unbalance have been limited. In this paper a comparison between different models of the ac motor and inverter of Adjustable-Speed Drives during balanced and unbalanced voltage sag conditions is studied using MATLAB/Simulink.

Keywords— Adjustable-Speed Drive (ASD), Power Quality and Voltage Sag

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Generic Application Programming Interface Design for Communication Protocols

Noman Sohaib Qureshi and Dr. Malik Muhammad Saad Missen

Department of Computer Science and Engineering, University of Engineering and Technology, Lahore Pakistan (Gujranwala Campus-RCET)
Department of Computer Science & Information Technology, The Islamia University of Bahawalpur, Pakistan

Abstract– The research proposal is to innovate a “Network Communication Application Programming Interface” which provides a platform to program network, communication applications on top of the API. The communication functionalities to be provided in this API are not limited to wired communication but it can be extended to program ‘wireless’ and ‘wireless sensor networks’. For the API to be used in wireless sensor network programming it is necessary that the functionalities to be provided by the API are programmed in a programming environment and in such a way that it consumes fewer resources considering the limited processing capabilities and power of the wireless sensor network platform. The design of this API will be in such a way that the network communication functionalities will be programmed purely and completely in C language and these will be in the form of Dynamic Link Libraries as an extension to the operating system kernel. For providing the WSN programming mode in this API it is necessary to avoid any translation or simulation layer for the ‘API core networking functionalities’. It is necessary to deploy the API in form of DLLs to directly communicate with the operating system in its native language i.e. DLLs as windows itself is a collection of dynamic link libraries mostly programmed in Win32/64 SDK C/C++. This API can be used to program the communication layers of the windows based WSN applications and the upper layer graphical user interface and monitoring applications can be programmed in any of the high level language. Despite WSN network programming this API will be useful to develop applications related to ‘Telephony’ or ‘TV broadcast’ and the scope is extendable to vast area of network communications applications. The area of research for this MS(Computer Science) Thesis is to propose, design and develop such a Network Communication API. In this paper, at first stage, the design of the API is presented.

Keywords— Application Programming Interface, Dynamic Link Libraries, Operating System Kernel and Wireless Sensor Networks

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Kinetics and Thermodynamics Study of Oil Extraction from Fluted Pumpkin Seed

J. T. Nwabanne

Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B. 5025, Awka, Nigeria

Abstract– The kinetics and thermodynamics of oil extraction from fluted pumpkin seed was studied. The influence of various parameters such as temperature, time, volume of solvent and particle size on oil yield was investigated. Oil yield increased with increase in temperature, time and volume of solvent but decreased with increase in particle size. Maximum oil yield of 46.98% was obtained at 1000C for an extraction time of 40 minutes using 20g of grounded fluted pumpkin seed and 100 ml of n-hexane. The physicochemical analysis of the oil showed that the oil is edible oil with an acid value of 4.77 mg NaOH/g, saponification value of 162.69 mg KOH/g and iodine value of 123.83 mgI2/100g. The oil has a viscosity of 119 cp, specific gravity of 0.9111, refractive index of 1.476, flash point of 1680C, pour point of -70C, and pH of 5.9. The kinetics of the fluted pumpkin seed oil extraction was studied using the power model and it was found that the order of reaction was fourth order, and had a rate constant of 1.58x10-7 (dm-3/mol) 3s-1. The thermodynamic study showed that the enthalpy change (ΔH) is positive, indicating that the extraction process is endothermic. The positive value of entropy change (ΔS) showed the randomness of the process while negative values of free energy change (ΔG) indicate that the process is feasible and spontaneous.

Keywords— Kinetics, Thermodynamics, Extraction and Fluted Pumpkin

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Reconfiguration for Loss Reduction of Distribution Systems Using Selective Particle Swarm Optimization

Tamer M. Khalil, Member, IEEE, and Alexander V. Gorpinich, Member, IEEE

Pryazovskyi State Technical University, Mariupol, Ukraine and Canal Co. for Electricity Distribution, Ismailia, Egypt
Electrical Engineering Department, Pryazovskyi State Technical University, Mariupol, Ukraine

Abstract– This paper aims to present a new simple algorithm for solving the distribution network reconfiguration (DNR) problem. This algorithm is a simple modification to the binary particle swarm optimization (BPSO) called selective particle swarm optimization (SPSO). The search space for proposed algorithm is a set of branches (switches) which are normally closed or normally opened, this search space may be dissimilar for different dimensions. The process of solving DNR problem is divided to two steps. First, finding search spaces after closing all switches and second, using SPSO to find switches that would be opened. The presented technique is applied to a 33-node system and a 69-node system. The results obtained via SPSO are compared with some previous methods to demonstrate the effectiveness of the proposed algorithm.

Keywords— Distribution Network, Reconfiguration, Selective Particle Swarm Optimization and Power Losses Reduction

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Computation of Technical Power Loss of Feeders and Transformers in Distribution System using Load Factor and Load Loss Factor

Sarang Pande and Prof. Dr. J.G. Ghodekar

Department of Electrical Engineering, K.K. Wagh Institute of Engineering & Research, Nashik, India

Abstract– Power system losses can be divided into two categories: technical losses and non-technical losses. Technical losses are naturally occurring losses (caused by actions internal to the power system) and consist mainly of power dissipation in electrical system components such as transmission lines, power transformers, measurement systems, etc. Technical losses result from the impedance of the network components such as electric lines/ cables, transformers, metering and protecting equipment etc. Non-technical losses, on the other hand, are caused by theft, metering inaccuracies. In this paper a method for energy loss calculation is presented.

Keywords— Line Loss, Transformer Loss, Load Factor, Load Loss Factor and Load Duration Curve

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Dealcoholization of Palm Wine Using Osmotic Membrane Distillation

Ejikeme Ebere M., Prof. Igbokwe P.K., and Ejikeme P.C.N

Met Department Proda, Enugu, Nigeria
Chemical Engineering Department, Nau Awka, Nigeria
Chemical Enginnering Department, Esut Enugu, Nigeria

Abstract– In this study, the possibility of using osmotic membrane distillation in reducing the alcohol content of palm wine was investigated. The effect of various process parameters such as temperature (30–40oC), stirring speed (0 – 100rpm) and membrane pore size (0.2–0.45µm) was studied. All the experiments were carried out on a membrane cell mode using hydrophobic polytetrafluroethylene membrane (PTFE). The design of experiments and its analysis was done using a design expert 8.0.2.Software. The statistical analysis done showed that the three factors studied had significant effects on the flux which is rise in water level. Flux was directly proportional to the temperature and stirring speed effects and inversely proportional to the membrane pore size effect. It was observed that of all the factors investigated, stirring speed had the highest effect with 29.3% increase followed by temperature with 20.4% increase and the least parameter was membrane pore size with 8.6% decrease on flux. It was deduced that flux which is the rise in water level is directly proportional to the amount of alcohol removed. The model equation was also obtained while the model adequacy check done revealed that the equation can adequately explain the process.

Keywords— Design of Experiment, Flux, Osmotic Membrane Distillation and Palm Wine

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Gas-Solid Flow Field and Particle Distribution in Bends with Circular Cross Section

Mehdi Bakhshesh and Majid Bakhshesh

Department of Mechanical Engineering, Behbahan branch, Islamic Azad University, Behbahan, Iran

Abstract– Natural gas always contains quantitative solid particles in various points of transport and distribution lines. These particles can accumulate in small passages such as regulators, gas burner devices and make difficulties. So, before natural gas enters into the city pipelines and residential areas must be filtered in central gas station (CGS) in addition to pressure reduction. In this paper, effect of flow Reynolds number and Stokes number upon particle deposition in bends have been investigated and compare the results with what has been found in literature. In addition, the effect of curvature ratio on penetration of particles in a 90o bend has been studied.

Keywords— Two Phase Flows, Gas-Solid, Deposition, Penetration Particles and Bend

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Modeling and Optimization of Electricity Distribution Planning System Using Dynamic Programming Techniques: A Case of Power Holding Company of Nigeria (PHCN)

Chinwuko C.E., Chukwuneke J.L., Okolie P.C., and Dara E.J.

Department of Industrial/Production Engineering, Nnamdi Azikiwe University, Awka Anambra, Nigeria
Department of Mechanical Engineering, Nnamdi Azikiwe University, Awka Anambra, Nigeria

Abstract– This paper presents a dynamic approach towards the sustainability of power distribution system using holistic application. The cost of energy losses, substation cost, feeder cost and outage cost was developed using dynamic programming technique and a three stage iterative solution with the aim to optimize the outage costs was presented. The three stages of optimization were carried out to determine, the number of substation sites and exact location, the feeder routes and the load flow in the network, and the outage cost to cover system node reliability evaluation. These three stages are solved sequentially by the optimization toolbox available with MATLAB. The substation and feeder stages were formulated as a quadratic mixed integer programming problem, while the outage stage was established as a non linear mixed integer programming problem. The proposed method has been applied to power distribution system planning for Awka Business Unit (PHCN), Anambra State, Nigeria. The model proposed a reserve substation capacity of approximately 15MVA at Agu-Awka to handle load expansion. Two substations were proposed after optimization, one sub-station at Nibo (existing) 30MVA, Second substation at Agu Awka 120MVA totaling 150MVA.

Keywords— Power, Optimization, Cost, Programming, Electricity, Substations, Distribution, Generation, Load Demand, Feeder and Outage

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Optimization of Steel Helical Spring by Composite Spring

Mehdi Bakhshesh and Majid Bakhshesh

Department of Mechanical Engineering, Behbahan branch, Islamic Azad University, Behbahan, Iran

Abstract– Springs that can reserve high level of potential energy, have undeniable role in industries. Helical spring is the most common element that has been used in car suspension system. In this research, steel helical spring related to light vehicle suspension system under the effect of a uniform loading has been studied and finite element analysis has been compared with analytical solution. Afterwards, steel spring has been replaced by three different composite helical springs including E-glass/Epoxy, Carbon/Epoxy and Kevlar/Epoxy. Spring weight, maximum stress and deflection have been compared with steel helical spring and factors of safety under the effect of applied loads have been calculated. It has been shown that spring optimization by material spring changing causes reduction of spring weight and maximum stress considerably. In any case, with changing fiber angle relative to spring axial, composite spring properties have been investigated.

Keywords— Helical Spring, Stress, Steel and Composite

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A 1.5v CMOS Fuzzifier

Behzad Ghanavati

Sama Technical and Vocational Training College, Islamic Azad University, Mahshahr Branch, Mahshahr, Iran

Abstract– A versatile low-voltage CMOS Fuzzifier circuit with a trapezoidal transconductance characteristic and independently programmable slope, height and horizontal position is designed in 0.35μm standard CMOS technology. Simulation results using HSPICE and level 49 parameters (BSIM3v3) that verify the functionality of circuit with 1.5 V supply are presented.

Keywords— Fuzzifier, Transconductor, Low-voltage, Low-power and Fuzzy

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QRS Detection by Fuzzy Controller

Behzad Ghanavati

Sama Technical and Vocational Training College, Islamic Azad University, Mahshahr Branch, Mahshahr, Iran

Abstract– This paper describes a QRS detector system to be implemented using 0.35µm CMOS technology which is used in biomedical applications. The proposed system uses fuzzy logic controller and several analog circuits for detecting QRS complexes and separating these parts from the rest of ECG signal. Simulation results using HSPICE that verify the functionality of system are presented.

Keywords— QRS Detection Algorithm, Fuzzy Logic Controller and Classifier

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