Latest issue - Internationial Review of Electrical Engineering (IREE)

Home>Products>Journal and Reviews>I.R.E.E.>Latest issue

International Review of Electrical Engineering - October 2006 - Papers

A Revised Electromagnetic Theory, by B. Lehnert
Dielectric Properties of Polyaniline Emeraldine Base, by P. Salovaara, M. Takala, K. Kannus
Matrix Converters: The Direct Control Approach Using Sliding Mode, by S. Ferreira Pinto, J. Fernando Silva
Modelling and Control of a Three-Phase Stacked Multilevel Voltage Source Inverter, by F. Ben Ammar, M. Ben Smida
Implementation of a Simple Rotating Master Control Scheme for Parallel Converters, by V. Pjevalica, H. H. C. Iu, B. Robert
Effects of Inverter Commutations on Common and Differential Mode Currents in Adjustable Speed Drive, by N. Idir, R. Bausière, J. J. Franchaud
FPGA Based Speed Control of Induction Motor, by B. Hariram, N. S. Marimuthu
Stator Current Minimization for a Field Oriented Controlled Induction Machine, by A. Boukhelifa, A. Chériti, R. Ibtiouen, O. Touhami
Analyzing the Effect of the Rotor Slit Depth on the Electric and Mechanical Performance of a Solid-Rotor Induction Motor, by T. Aho, J. Nerg, J. Sopanen, J. Huppunen, J. Pyrhönen
On the Implementation of Neural Networks on FPGA Circuits: Application to Real Time Speed Control of DC Motor, by C. Benbouchama, S. Sakhi, M. Tadjine, A. Bouridane
Synthesis of a Fixed Structure Controller Using Time Constrained Output Feedback: Application to DC Motor Control, by N. Maamri, JP. Gaubert, JC. Trigeassou
Reliability Modelling of Uninterruptible Power Supply Systems Using Reliability Block Diagram Method, by M. K. Rahmat, S. Jovanovic
Consideration of the Guard Line in the Overhead Transmission Line Parameter Computation, by A. Abadlia, F. Ghodbane, M. Elleuch
Minimization of Fluctuations of Line Power and Terminal Voltage of Wind Generator by Fuzzy Logic-Controlled SMES, by M. H. Ali, T. Murata, J. Tamura
The Autonomous Electrical Power System of Crete Island - A Review, by Y. L. Karnavas
E-learning Concept for Electrical Engineering, by V. Fedák, P. Bauer

International Review of Electrical Engineering - Papers

A Revised Electromagnetic Theory
by B. Lehnert

Vol. 1. n. 4, pp. 452-461

Abstract - A revised Lorentz and gauge invariant electromagnetic theory has been developed, as based on a nonzero electric field divergence and an associated space-charge current density in the vacuum state. The theory aims beyond Maxwell’s equations and presents new solutions of a number of fundamental problems. So far the latter have not been satisfactory explained in terms of conventional electromagnetic theory and quantum electrodynamics (QED). Important applications of the revised theory are presented, such as on a model of the electron and its point-charge-like nature, the self-energy problem, the radial force balance, and a quantized minimum value of the electron charge. There are further applications on the individual photon and its angular momentum, its spatially limited geometry, the associated needle radiation, and the particle-wave nature of the photoelectric effect and two-slit experiments at low photon densities.

Keywords: Electromagnetic field theory, vacuum state, quantum electrodynamics, leptons, photon.

Dielectric Properties of Polyaniline Emeraldine Base

by P. Salovaara, M. Takala, K. Kannus

Vol. 1. n. 4, pp. 462-467

Abstract - Dielectric properties such as permittivity, loss factor and conductivity of pure polyaniline emeraldine base PANI-EB pellets are measured as a function of electric field and frequency. Dielectric properties are measured in the electric field range from 0.2 kV/mm to 2.45 kV/mm and in the frequency range from 0.1 Hz to 1 kHz. Measurement results clearly show that relative permittivity, loss factor and conductivity of PANI EB increase as a function of increasing electric field. Relative permittivity of PANI EB is also quite high, approx. 20 even in the lowest electric field at 50 Hz. On the other hand relative permittivity also increases as a function of decreasing frequency range as well as the loss factor. Only conductivity increases as a function of increasing frequency. The formalism of electric modulus is also studied in the paper.

Keywords: Complex electric modulus, electric field dependency, frequency characteristics, permittivity, polyaniline emeraldine base.

Matrix Converters: The Direct Control Approach Using Sliding Mode
by S. Ferreira Pinto, J. Fernando Silva

Vol. 1. n. 4, pp. 468-479

Abstract - This paper presents a new approach to solve the direct control problem of matrix converters with input LC filters using the sliding mode control technique. Sliding mode controllers can be tailored to consider the dynamics of the converter and its associated LC filter and, together with the space vector representation technique, can determine the switching from one bidirectional switch to another, being appropriate to the non-linear on-off behavior of the matrix converter power semiconductors. Moreover, this switching occurs just in time, guaranteeing fast response times and precise control actions, ensuring that the output voltages and the input currents track their references, thus allowing the input power factor regulation. This regulation, can be made independent of the input filter parameters, which is useful in applications requiring unity input power factor, such as ac drives, or applications needing variable and accurate input power factor regulation, usually related to power quality enhancement. The simulations and obtained experimental results with a laboratory prototype show that the designed sliding mode controllers ensure the direct control of matrix converters output variables over a wide range of output frequencies (0.01 Hz to 300 Hz) and guaranteeing a leading or lagging input power factor regulation.

Keywords: Matrix Converters, Space Vector, Sliding Mode Control.

Modelling and Control of a Three-Phase Stacked Multilevel Voltage Source Inverter
by F. Ben Ammar, M. Ben Smida

Vol. 1. n. 4, pp. 480-489

Abstract - The flying voltage source multilevel inverters are suitable in high voltage, high power applications, to bypass technologic limitations of the semiconductors devices. In this paper authors propose a general mathematical model for a new topology called SMC “Stacked Multicell Converter”. Each phase of the SMCn×m multilevel inverter is formed by a stack of m individual flying capacitor multilevel inverter, each stack or stage is realised by connecting in series n controllable commutation cells. An original multi-carrier sub-harmonic pulse width modulation method is developed to produce (n×m+1) output voltage levels and to improve the output voltage harmonic spectrum with a wide output frequency range. To carry out in practice the SMCn×m modulation technique, the minimum turn-on-time and minimum turn –off time of the IGBTs switching devices are taken into account in adjustment of modulation characteristics. A simulation results are carried out from Matlab-Simulink circuit simulation. The implementation of the modulation control strategy has been done in Field Programmed Gate Array circuit (FPGA) XC4010E+ of XILINX to control a three phase SMC3×2 seven level inverter and the experimental results are carried out to confirm the high performance of this inverter.

Keywords: Multilevel Inverter, Stacked Multilevel Converter, SMC nxm, multi-carrier modulation.

Implementation of a Simple Rotating Master Control Scheme for Parallel Converters

by V. Pjevalica, H. H. C. Iu, B. Robert

Vol. 1. n. 4, pp. 490-495

Abstract - Rotating master-slave current programming method (RMSCPM) is known in theory for long time. Advantage of the rotating master method is better system reliability, compared to the dedicated master method. However, practical implementation of this method can be very complicated due to a large number of signals to be swapped during control rotation. This paper presents a practical scheme for extremely simple implementation of rotating master-slave current programming method (RMSCPM).

Keywords: Current sharing control, dc/dc converter, parallel converters.

Effects of Inverter Commutations on Common and Differential Mode Currents in Adjustable Speed Drive

by N. Idir, R. Bausière, J. J. Franchaud

Vol. 1. n. 4, pp. 496-502

Abstract - In Adjustable Speed Drives (ASD), increasing the switching frequency of power devices in PWM inverters induces high voltage variations (dv/dt) leading to conducted emissions at high frequencies which are propagated both through Common Mode (CM) and Differential Mode (DM) in the system. The circulation of high frequency parasitic currents causes several unexpected problems, such as premature deterioration of motor winding insulation and ball bearings.
The operating PWM inverter can be reduced to two commutation modes: commutation from diode to transistor associated with diode reverse recovery where the highest dv/dt may occur, and commutation from transistor to diode where dv/dt value depend of the dead time duration that is inserted in the control signals to prevent dc link shortages.
This paper deals with the influence of PWM inverter operating commutation types and dead time duration on common mode and differential mode current distribution, showing that both propagation modes may be linked.

Keywords: Adjustable Speed Drives, Common Mode Current, Differential Mode Current, ElectroMagnetic Interference (EMI), Power Switching.

FPGA Based Speed Control of Induction Motor

by B. Hariram, N. S. Marimuthu

Vol. 1. n. 4, pp. 503-509

Abstract - This paper proposes a fully digitized hardware design scheme of a Space Vector Pulse Width Modulation (SVPWM) based V/f control, which is verified and implemented on a single chip Field Programmable Gate Array (FPGA), for the speed control of three phase induction motor. This is also implemented in Digital Signal Processor (DSP) as FPGA and DSP are the good compromise between the advantage of the flexibility of a programming solution and the efficiency of a specific architecture with a high integration density. These characteristics are quite appropriate for controller design. The comparison of the experimental results especially, Execution time and maximum circuit delay from the DSP and FPGA based implementation respectively, provides guideline on the superiority of FPGA based solution of Industrial Drives in general.

Keywords: FPGA, SVPWM, DSP, V/f control.

Stator Current Minimization for a Field Oriented Controlled Induction Machine

by A. Boukhelifa, A. Chériti, R. Ibtiouen, O. Touhami

Vol. 1. n. 4, pp. 510-515

Abstract - This paper presents the stator current minimization in an induction machine controlled by the field oriented strategy. This minimization is realized by two different methods: the first is an optimization in the steady state, the second is the dynamic programming method that optimizes the current in any regime. For each optimization method, flux in the machine is no more constant as it is the case in the conventional vector control, but it evolves according to the operating point. The results obtained from the simulation of the optimization method, carried out in the Matlab/Simulink environment, are presented at the end of this article. These results are compared to those resulting from constant flux operation and show substantial improvement.

Keywords: Dynamic Programming, Induction Machine, Stator Current Minimization, Vector Control.

Analyzing the Effect of the Rotor Slit Depth on the Electric and Mechanical Performance of a Solid-Rotor Induction Motor
by T. Aho, J. Nerg, J. Sopanen, J. Huppunen, J. Pyrhönen

Vol. 1. n. 4, pp. 516-524

Abstract - The effect of the rotor slit depth on the performance characteristics as well as the mechanical strength of a medium-speed solid-rotor induction motor is discussed. A FEM-based analysis is applied to obtain the electromagnetic performance of the motor. An analytical method for the prediction of the nominal stress of the slitted solid rotor structure is proposed. The comparison of the results obtained from the electromagnetic and mechanical analyses shows that when operating at the peripheral speed range from 100 to 200 m/s, the maximum rotor slit depth should be about a half of the rotor radius assuming that the mechanical stresses do not limit the slit depth to a lower value.

Keywords: Solid rotor, induction motor, modeling, mechanical strength analysis.

On the Implementation of Neural Networks on FPGA Circuits: Application to Real Time Speed Control of DC Motor
by C. Benbouchama, S. Sakhi, M. Tadjine, A. Bouridane

Vol. 1. n. 4, pp. 525-534

Abstract - This paper describes an efficient implementation of neural multi-layer networks on FPGA fabric (Field Programmable Gate Array). A back-propagation algorithm was used for the training task while implementation and synthesis tools are centred on the ISE 6.3 of Xilinx with the targeted components being VirtexII and VirtexIIPro. A fixed point and a floating point number representation were used for encoding real numbers and for data processing, respectively. The realization of the activation function was carried out according to three methods, for which the results of simulation and synthesis are also presented. The implementation performances were tested using an approximation of some linear and non-linear functions. Of particular importance, an experimental evaluation involving the speed control of a DC motor is given to demonstrate the features of the adopted methodology.

Keywords: Back propagation, Control, FPGA, Implementation, Neural Networks.

Synthesis of a Fixed Structure Controller Using Time Constrained Output Feedback: Application to DC Motor Control
by N. Maamri, JP. Gaubert, JC. Trigeassou

Vol. 1. n. 4, pp. 535-542

Abstract - In this paper we present a synthesis method for stabilizing controllers with a time constraint in the case of LTI (Linear Time Invariant) systems. The controller structure and dynamics are fixed. The time constraint is expressed using an equality between the time moments of the closed loop system and those of a reference model. The Linear Matrix Inequality (LMI) formalism is used in this paper. An application to a DC motor is given to illustrate the proposed method.

Keywords: Fixed structure controllers, Output feedback, Time Moments, LMI, DC motor.

Reliability Modelling of Uninterruptible Power Supply Systems Using Reliability Block Diagram Method
by M. K. Rahmat, S. Jovanovic

Vol. 1. n. 4, pp. 543-551

Abstract - The aim of this paper is to investigate the reliability parameters prediction method for the Uninterruptible Power Supply (UPS) systems using the Reliability Block Diagram (RBD) technique. In contrast with the existing UPS reliability prediction methods that requires more input data and computationally tedious, the new approach provides a useful and fast method to evaluate the system’s Failure rates (), Mean Time Between Failures (MTBF), Availability and Unavailability of the UPS systems. In this paper, reliability parameters obtained from five major AC UPS configurations (online with and without bypass, offline, line-interactive with buck/boost transformer and line-interactive with ferroresonant transformer) were compared and discussed in detail. Equations for calculating the MTBF and Unavailability are presented along with component reliability estimates. Sensitivity analysis on UPS components was performed to investigate the effect on the overall system reliability. Finally, to validate the results obtained from this RBD method, comparisons were made to the results from other reliability estimation method such as the Boolean Truth Table, Probability Tree, Fault Tree Analysis, Monte-Carlo Simulation method and Field Data estimation method.

Keywords: Reliability modelling, Reliability Block Diagram, Uninterruptible power supply.

Consideration of the Guard Line in the Overhead Transmission Line Parameter Computation
by A. Abadlia, F. Ghodbane, M. Elleuch

Vol. 1. n. 4, pp. 552-558

Abstract - In this paper, the authors treat the modelling of overhead electric lines equipped with a guard line. Omissions, presented by conventional methods parameters calculation, related to the guard line current and potential are raised. Conventional methods assume that the guard line current is homogeneous and its potential is null. This work is devoted to check the authenticity of these assumptions and to proove their limitation to a particular case. However, a guard line model, taking into account its earthing resistance, was proposed. Simulation results, based on this model, were experimentally validated. Consequently, a new approach of impedance matrix computation is proposed. Transmission line impedance matrix will be computed, for border case, by conventional method and the new approach.

Keywords: Earthing resistance, Guard line current and potential, Impedance matrix, Induced current.

Minimization of Fluctuations of Line Power and Terminal Voltage of Wind Generator by Fuzzy Logic-Controlled SMES
by M. H. Ali, T. Murata, J. Tamura

Vol. 1. n. 4, pp. 559-566

Abstract - Due to random variations of wind speed, the output power and terminal voltage of a fixed speed wind generator fluctuates continuously. Consequently the line power fluctuates. This paper presents a fuzzy logic-controlled SMES (superconducting magnetic energy storage) scheme for minimization of fluctuations of line power and terminal voltage of wind generator during wind speed variations. The transient stability enhancement of wind generator by the fuzzy logic-controlled SMES during unsuccessful reclosing of circuit breakers is also discussed. The control scheme of SMES is based on a sinusoidal PWM (Pulse Width Modulation) voltage source converter (VSC) and a two-quadrant DC-DC chopper using Gate-turn-off (GTO) thyristor. Simulation results demonstrate that the proposed fuzzy logic-controlled SMES is a very effective means of minimization of fluctuations of line power and terminal voltage of wind generator during wind speed variations. Moreover, the proposed fuzzy controlled SMES is able to stabilize the wind generator as well as the entire power system well during unsuccessful reclosing of circuit breakers.

Keywords: DC-DC Chopper, Fuzzy Logic Controller, Minimization of Fluctuations, PWM (Pulse Width Modulation), SMES (Superconducting Magnetic Energy Storage), Unsuccessful Reclosing, Wind Generator Stabilization, Wind Speed Variations.

The Autonomous Electrical Power System of Crete Island - A Review
by Y. L. Karnavas

Vol. 1. n. 4, pp. 567-574

Abstract - A systematical effort is made in this paper to present a thorough review, through an up to date literature survey, regarding the electrical power system of Crete island (EPSC) located in Greece. The EPSC is a large autonomous power system and its main characteristic is that, the load demand presents high seasonal variations and also increases rapidly. The annual increase rate is approximately 8% and the peak load demand has been doubled the last 12 years. Electricity generation is produced by conventional units (diesel units, steam and gas turbine generators and combined cycle) and also with the aid of renewable energy sources (RES). The installation of wind turbines (W/Ts) in Crete started on 1992 and up to now the wind power has a great percentage of penetration in the EPSC. There are primarily three main reasons that have caused the interest of many researchers to study the EPSC the last 15 years and subsequently produce quite large research work until today: a) The significant increase of the load demand in the island, b) the great percentage of W/Ts’ penetration in the EPSC and c) the old technology conventional units with which the EPSC is mainly composed and which in turn have a high running cost. An attempt is made by the author to present the EPSC in detail, giving an overall view of the system (data for the generation units, substations, wind parks and the grid), as well as the total relevant research concerning the EPSC, since something analogous has not been done yet in the literature. Many aspects concerning the EPSC are presented such as; load forecasting, RES and their connection to the grid, dynamic stability, economic operation, reliability, protection and dynamic security. It is an author's expectation that researchers in the future who are interested in the EPSC can draw data from this paper and keep up with the up to date research.

Keywords: Autonomous power systems, renewable energy sources, load forecasting, dynamic stability, economic operation, reliability, protection, dynamic security.

E-learning Concept for Electrical Engineering
by V. Fedák, P. Bauer

Vol. 1. n. 4, pp. 575-581

Abstract - The paper presents philosophy at development of new multimedia modules covering several fields of electrical engineering related to subjects such as power electronics, electrical drives and systems. The modules are suitable both for teaching (lecturing) and learning (self-learning). Advantages of the accepted philosophy are explained on several typical examples. The multimedia rich modules contain several interactive tools promoting the high level of university education. Animations enhance complicated phenomena and interactive features enable to perform small simulation experiments and to evaluate influence of the parameter change to behaviour of the circuit/system. The results are presented in series of the screens chosen from various e-learning modules.

Keywords: Education, E-learning, Electrical Drives, Power Electronics, Interactive Animations.

International Review of Electrical Engineering - October 2006 - Papers

Implementation of a Simple Rotating Master Control Scheme for Parallel Converters

Please send any questions about this web site to info@praiseworthyprize.com

- Copyright © 2005-2010 Praise Worthy Prize -