2011: Volume 34, Number 1                                                      2011: Volume 34, Number 2

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2011: Volume 34, Number 1

Table of Contents

 

Cătălin Anghel: New Eavesdropper Detection Method in Quantum Cryptograph (pp. 1-8)
 Abstract  Full Text

Viorel Nicolau, Mihaela Andrei: Aspects of Fuzzy Parameter Tuning for Partitive Clustering Algorithms Based on Potential Functions (pp. 9-14)
 Abstract  Full Text

Ciprian VLAD, Mihaela SBARCIOG, Marian BARBU: Linear Predictive Control of a Wastewater Treatment Process (pp. 15-20)
Abstract  Full Text

P. KANNAN , S. Chenthur PANDIAN : A Power Quality Improvement in Fourteen Bus System Using Unified Power Flow Controller (pp. 21-26)
 Abstract  Full Text

Ciprian BALANUTA, Gelu GURGUIATU, Toader MUNTEANU, Grigore FETECAU: Comparison of Three Phase 4-Leg Shunt Active Power Filter using dq, Indirect and Maximum Control Method (pp. 27-32)
 Abstract  Full Text

Madalin COSTIN, Elena VONCILA, Ion VONCILA, Cristian NICHITA, Grigore FETECAU: Development of Wind Turbine Systems with Parallel Connections of Different Types Generators  (pp. 33-39)
 Abstract  Full Text

 

 

 

Cătălin Anghel: New Eavesdropper Detection Method in Quantum Cryptograph


Abstract: Security of quantum cryptographic algorithms is one of the main research directions in quantum cryptography. Security growth of the quantum key distribution systems can be realized by detecting the eavesdropper quickly, precisely and without letting any secret information in the hands of the enemy. This paper proposes a new method, named QBTT, to detect the enemy who try to tap the communication channel. The QBTT method can be implemented in every type of quantum key distribution scheme.


Keywords: quantum cryptography, quantum physics, quantum key distribution, qkd, cryptography, quantum algorithm.

 

 

 

 

Viorel Nicolau, Mihaela Andrei: Aspects of Fuzzy Parameter Tuning for Partitive Clustering Algorithms Based on Potential Functions


 Abstract: In clustering algorithms, potential functions can be used as a measure of similarity, characterizing the membership of a point to a group of points. Potential function-based algorithms (PFBA) are suited for clustering of complex-shape data sets, without knowing in advance the number of clusters. Also, they make no implicit assumptions on the cluster shapes and do not use any prototype vectors of the clusters. The parameter of potential function has direct influence on clustering performance. In this paper, some expert rules of PFBA are generated for using in selecting process of parameter values. A fuzzy system for parameter tuning of PFBA is studied, so that the best clustering to be obtained with less seeking efforts.

 Keywords: Fuzzy System, Clustering Algorithms, Potential Function, Parameter Tuning.

 

 

 

 

Ciprian VLAD, Mihaela SBARCIOG, Marian BARBU: Linear Predictive Control of a Wastewater Treatment Process


 Abstract: The paper deals with the control of effluent substrate concentration from a wastewater treatment process described by a nonlinear model. The control variable is the dilution rate. The switching of the operating points and of the linear models of the process is based on the aeration rate value. The contribution of the paper consist in the fact that the effluent substrate concentration is controlled through linear predictive control without using measurements of the substrate, only by measuring the dissolved oxygen concentration, which is most economically.

Keywords: Predictive control, wastewater treatment, dissolved oxygen control, Activated Sludge Process.

 

 

 

 

 

P. KANNAN , S. Chenthur PANDIAN : A Power Quality Improvement in Fourteen Bus System Using Unified Power Flow Controller


Abstract: This work deals with Modeling and Simulation of 14 bus system employing Unified Power Flow Controller (UPFC). The UPFC is a Flexible AC Transmission Systems (FACTS) device used for improving the power quality in power systems. Simulink model is developed for 14 bus systems with and without UPFC. Digital simulation is done with this model and results are presented. The effect of UPFC on the nearby buses in a multibus system is also presented.

Keywords: FACTS, UPFC, Power Quality, MATLAB, SIMULINK.

 


 

 

Ciprian BALANUTA, Gelu GURGUIATU, Toader MUNTEANU, Grigore FETECAU: Comparison of Three Phase 4-Leg Shunt Active Power Filter using dq, Indirect and Maximum Control Method


 Abstract: : In this paper is presented a comparative analysis of three control methods for a three-phase active power filter (APF) with four legs, aiming at the power quality indicators: THD, power factor, unbalance. The results are obtained by simulation in Matlab/Simulink of a three-phase electrical system supplied by four wires.

Keywords: active power filter (APF), control method, power quality.

 


 

 

Madalin COSTIN, Elena VONCILA, Ion VONCILA, Cristian NICHITA, Grigore FETECAU: Development of Wind Turbine Systems with Parallel Connections of Different Types Generators


Abstract: The work paper explores the possibility of wind power conversion systems developing by parallel coupling of main different types power AC generators such as induction generator and permanent magnet synchronous one in isolated grid. Due to different electromagnetic processes underlying operation, the currents per phase developed present different differences phase, and therefore is usually obtain a low output power. It was found that optimizing the output current can be made by choosing appropriate an optimal combination of pole pairs for different generators.

Keywords: induction generator, permanent magnet synchronous generator, wind turbine systems, Psim software.

 

 

   

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2011: Volume 34, Number 2

Table of Contents

 

Alina CHIROŞCĂ, George DUMITRAŞCU, Laurentiu LUCA, Sergiu CARAMAN: Fuzzy Control of the Activated Sludge Wastewater Treatment Process Treated as Multivariable Process  (pp. 1-5)
Abstract  Full Text

Cătălin ANGHEL: New Quantum Cryptographic Protocol (pp. 7-13)
 Abstract  Full Text

Elena VONCILA, Madalin COSTIN, IonVONCILA, Cristian NICHITA, Grigore FETECAU: An Analysis of Dynamics Regimes of Parallel Generators Operation in Wind Turbine Systems (pp.15-21)
 Abstract  Full Text

Marian GAICEANU, Cristi DACHE, Emil ROSU, Traian MUNTEANU, Romeo PADURARU, Teodor DUMITRIU: Model Reference Adaptive Control of a Vector Controlled Three Phase Induction Machine (pp. 23-27)
Abstract  Full Text

S. ARUMUGAM  and S. Rama REDDY : A Noval Comparison of Class D and Class E Inverter Based High Frequency Application (pp. 29-35)
 Abstract  Full Text

Silviu EPURE, Emil ROŞU: Low Power Battery Charger with Solar Panel Input, the Electronic Circuit  (pp.37-42)
 Abstract   Full Text

 

 

 

Alina CHIROŞCĂ, George DUMITRAŞCU, Laurentiu LUCA, Sergiu CARAMAN: Fuzzy Control of the Activated Sludge Wastewater Treatment Process Treated as Multivariable Process (pp. 1-5)


Abstract: The paper deals with the design of a fuzzy controller of a wastewater treatment process in which the organic substances are removed. The process is complex, nonlinear, time-varying and multivariable, so is necessary to analyze the disturbance rejection and robustness problems. The main contribution of this paper is to give a multivariable fuzzy controller for step disturbance and uncertainty rejection in the wastewater treatment process.

Keywords: fuzzy control, multivariable control, wastewater treatment plant, robustness, disturbance rejection.

 

 

 

 

Cătălin ANGHEL: New Quantum Cryptographic Protocol (pp. 7-13)


Abstract: One of the main research directions of quantum cryptography is to discover new algorithms and to improve the existing ones. This paper proposes a new quantum cryptographic algorithm based on BSTS algorithm with QBTT method of eavesdropper detection which can realize a perfectly secure communication between two computers.

Keywords: quantum cryptography, quantum physics, quantum key distribution, qkd, quantum algorithm, bsts, qbtt.

 

 

 

 

Elena VONCILA, Madalin COSTIN, IonVONCILA, Cristian NICHITA, Grigore FETECAU: An Analysis of Dynamics Regimes of Parallel Generators Operation in Wind Turbine Systems (pp.15-21)


Abstract: The parallel connection of different types of AC generators, used as example in isolated sites, represents a difficult problem due to the different particularities of the that generators involved. This paper analyses the specific dynamic processes that may occur with the development of such systems. Although some dynamic processes that not affect the magnetic and/ or electric symmetry of the system can be excellent modelled through models, most of them cannot take into account such symmetry, reason to resort the models in phase coordinates, often implemented with professional Software (Psim). The dynamical particularities obtained by simulations revealed different dynamics in most of the regimes, prefigured by the different nature of the generators: asynchronous and synchronous. Further development using automatic control techniques will allow uniform integration of such systems with different dynamics.

Keywords: dynamical regimes, permanent magnet synchronous generator, induction generator, wind turbine systems, numerical simulation.

 

 

 

 

Marian GAICEANU, Cristi DACHE, Emil ROSU, Traian MUNTEANU, Romeo PADURARU, Teodor DUMITRIU: Model Reference Adaptive Control of a Vector Controlled Three Phase Induction Machine (pp. 23-27)


Abstract: Model reference adaptive control (MRAC) of three-phase induction machine in rotor field coordinated is proposed in this paper. The proposed adaptive structure is in direct form, such that the controller parameters are obtained on-line. The adaptive mechanism of the parameters is obtained by additive composing of two terms: the first will support a gradient adjustment law and the second will comport an adjustment that includes a sigmoid function specific for variable structure control. The last component improves the transient and steady state response by eliminating the small oscillations of the closed loop response around the equilibrium state in order to obtain a zero tracking error. The adaptive mechanism assures the robustness to the external disturbances and to the unmodeled dynamics. Matlab/Simulink based simulation results will show the effectiveness of the proposed solution.

Keywords: rotor field oriented, model reference adaptive control, induction motor, Matlab/Simulink.

 

 

 

 

S. ARUMUGAM and S. Rama REDDY : A Noval Comparison of Class D and Class E Inverter Based High Frequency Application (pp. 29-35)


Abstract: This paper deals with the simulation and implementation of class E inverter based induction heater system. Class E inverter is analyzed; simulated and implemented. Utility frequency AC Power is converted into high frequency AC power using class E inverter. This high frequency AC is used for induction heating. Open and closed loop systems are modeled and they are simulated using Matlab Simulink. The results of simulation and implementations are presented. The laboratory model is implemented and the experimental results are obtained. These Experimental results are correlated with the simulation results.

Keywords: High Frequency Inverter, Induction Heating Heating (IH), Push-Pull Amplifier, Zero Voltage Source (ZVS), Simulink.

 

 

 

 

Silviu EPURE, Emil ROŞU: Low Power Battery Charger with Solar Panel Input, the Electronic Circuit  (pp.37-42)


Abstract: This paper presents an electronic circuit to be used as interface between a low-power (20W) low voltage (6V) solar panel and a lead-acid Li-Ion 12V battery. A low-cost microcontroller drives a boost circuit, connected between the solar panel and the battery, to maintain the battery in fully charged state as long as possible. All aspects regarding hardware design are presented together with experimental results that confirm the ability of the circuit to perform the task.

Keywords: dc/dc converter, current transducer, board design, microcontroller.