ELEKTRYKA - Issue 4/2010 (216) - Politechnika Śląska, Wydział Elektryczny

ELEKTRYKA - Issue 4/2010 (216)

ELEKTRYKAYear LVI (2010)

QuarterlyIssue 4 (216)

CONTENTS

Foreword

Aleksander BODORA, Tomasz BISKUP, Arkadiusz DOMORACKI: Calibration of absolute encoder with permanent magnet motor
Krzysztof BUDNIK, Wojciech MACHCZYŃSKI: Analytical magnetic field calculation of helical current conductors
Grzegorz POPEK, Marian KAMPIK, Krzysztof MUSIOŁ: Root mean square value of the signal generated by direct digital synthesser in presence of phase accumulator word truncation and dac finite resolution
Roman NIESTRÓJ, Tadeusz BIAŁOŃ, Marian PASKO: Stability analysis of the MRAS-type estimator taking into consideration parameter changes of the model of the induction motor
Marcin KOWOL, Adrian MŁOT, Marian ŁUKANISZYN, Krzysztof LATAWIEC: Applications of an evolutionary algorithm in construction optimization of electrical motors
Joanna KOLAŃSKA-PŁUSKA: Application FLUX 3D programme to the analysis of the magnetic field in a tubular workpiece heated from outside by induction
Jerzy JAKUBIEC, Beata KRUPANEK, Maciej GRYGIEL: Probabilistic modelling of communication delays in computer systems
Wojciech BURLIKOWSKI: Two-axis transformation for current and flux state variables applied to reluctance motor with wye connected winding without neutral wire
Marcin KASPRZAK: 13,56 MHz/500 W class DE inverter with flyback topology driver–measurement of efficiency

Aleksander BODORA, Tomasz BISKUP, Arkadiusz DOMORACKI

Katedra Energoelektroniki, Napędu Elektrycznego i Robotyki, Politechnika Śląska w Gliwicach

CALIBRATION OF ABSOLUTE ENCODER WITH PERMANENT MAGNET MOTOR

Summary. The paper presents a method for absolute encoder calibration. Calibration consists in determining the offset between the sensor zero position and the stator phase axis. This offset is introduced into a control system as the correction value. The presented method of calibration is relatively simple for implementation. It can also be automatically realized by a control system. The paper presents the results of computer simulations illustrating the idea of the method as well as the results of laboratory tests. These tests proved possibility of using this method in industrial conditions.

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Krzysztof BUDNIK, Wojciech MACHCZYŃSKI

Instytut Elektrotechniki i Elektroniki Przemysłowej, Politechnika Poznańska

ANALYTICAL CALCULATION OF MAGNETIC FIELD OF HELICAL CURRENT CONDUCTORS

Summary. The paper presents a theoretical study of calculating magnetic fields in the vicinity of conductors having helical structure. In the case of an infinitely long helical conductor, the magnetic vector potential can be expressed using the series expansion of the reciprocal distance between the observation and source points, whereas for a helical conductor with finite length the method is based on the Biot-Savart law. The analytical formulas for calculating the 3D magnetic field are derived. The formulas can be used by a software tool to model the magnetic fields generated by e.g. twisted wires, helical coils, etc. The exemplary calculations show the usefulness of the formulas given in the paper.

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Grzegorz POPEK, Marian KAMPIK, Krzysztof MUSIOŁ

Instytut Metrologii i Automatyki Elektrotechnicznej, Politechnika Śląska w Gliwicach

ROOT MEAN SQUARE VALUE OF A SIGNAL GENERATED BY DIRECT DIGITAL SYNTHESSER IN PRESENCE OF PHASE ACCUMULATOR WORD TRUNCATION AND DAC FINITE RESOLUTION

Summary. The paper presents influence of phase word truncation effect and finite resolution of DAC on the signal root mean square value generated by Direct Digital Synthesizer (DDS). The proposed mathematical model allows setting the frequency range and parameters of DDS i.e. number of bits in a phase word to achieve the RMS error smaller than the assumed value.

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Roman NIESTRÓJ, Tadeusz BIAŁOŃ, Marian PASKO

Instytut Elektrotechniki i Informatyki, Politechnika Śląska w Gliwicach

STABILITY ANALYSIS OF THE MRAS-TYPE ESTIMATOR TAKING INTO CONSIDERATION CHANGES OF INDUCTION MOTOR MODEL PARAMETERS

Summary. The paper presents results of stability and reconstruction quality analysis performed for the MRAS-type estimator in the steady-state of rotor speed as well as stator and rotor magnetic fluxes of an induction motor, obtained when taking into consideration simultaneous changes of all parameters of the induction motor model. Investigations were performed for a large number of sets of the motor model parameters with random deviations. The investigation results were statistically worked out.

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Marcin KOWOL, Adrian MŁOT, Marian ŁUKANISZYN, Krzysztof LATAWIEC

Instytut Układów Elektromechanicznych i Elektroniki Przemysłowej, Politechnika Opolska

APPLICATION OF AN EVOLUTIONARY ALGORITHM TO OPTIMIZATION OF ELECTRICAL MOTOR CONSTRUCTION

Summary. This paper deals with evolutionary optimization of construction parameters for brushless DC permanent magnet (BLDC) and transverse flux (TFM) motors. For a BLDC motor, the permanent magnet shape parameters are optimized to provide a minimum cogging torque. It is shown that the cogging torque in a motor with multipolar excitation of permanent magnets is reduced six times as compared with a conventional BLDC motor. For a TFM, the magnetic circuit construction parameters are optimized to compromise between the high electromagnetic torque and low torque pulsations. For both motors, the evolutionary optimization algorithm is coupled with a 3D FEM program employed for precise modelling of the electromagnetic field.

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Joanna KOLAŃSKA-PŁUSKA

Instytut Układów Elektromechanicznych i Elektroniki Przemysłowej, Politechnika Opolska w Opolu

APPLICATION OF FLUX 3D PROGRAM TO ANALYSIS OF THE MAGNETIC FIELD IN A TUBULAR WORKPIECE HEATED FROM OUTSIDE BY INDUCTION

Summary. The electromagnetic field was calculated in all areas of a system: external inductor – tubular workpiece. Numerical analysis was performed for two sides of the inductor. The magnetic field distribution was calculated by the Flux3D program. Analysis of the electromagnetic field was made by the finite element method (FEM). The heating process was simulated and analyzed in the Flux3D program. However, only one part concerning the magnetic field distribution is presented in this paper. This is the finite element software for electromagnetic and thermal solution. The presented research show advantages of using a computer program such as Flux 3D.

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Jerzy JAKUBIEC, Beata KRUPANEK, Maciej GRYGIEL

Instytut Metrologii, Elektroniki i Automatyki, Politechnika Śląska w Gliwicach

PROBABILISTIC MODELLING OF COMMUNICATION DELAYS IN COMPUTER SYSTEMS

Summary. The paper describes a new modeling method of delays in computer networks. The method is based on probabilistic description of the access time to a medium and using a time series of delta functions to describe the transmission time of a message from a transmitter to a receiver. Theoretical considerations have been illustrated by measurement results obtained by using an experimental wireless system that works in conditions in which some factors influencing the transmission, such as barriers and routers, are present.

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Wojciech BURLIKOWSKI

Katedra Mechatroniki, Politechnika Śląska w Gliwicach

TWO-AXIS TRANSFORMATION FOR CURRENT AND FLUX STATE VARIABLES APPLIED TO RELUCTANCE MOTOR WITH WYE CONNECTED WINDING WITHOUT NEUTRAL WIRE

Summary. In the paper influence of absence of a neutral wire in the wye connected winding on the form of two-axis transformation is presented. In order to formulate this transformation, a set of elementary circuit simplifications is used. In contrast to the classical Park transformation which is the same for all variables, in the proposed modified transformation the matrices obtained for currents and fluxes/voltages are different, yet strongly interconnected. This ensures preservation of the most important features of the classical transformation. The voltage equation obtained using the proposed transformation is the same as in the case of the classical transformation. The inductance matrix in the dq reference frame in the case of an idealised reluctance motor is diagonal. The invariance of power is preserved.

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Marcin KASPRZAK

Katedra Energoelektroniki, Napędu Elektrycznego i Robotyki, Politechnika Śląska w Gliwicach

13,56 MHZ/500 W CLASS DE INVERTER WITH FLYBACK TOPOLOGY DRIVER–MEASUREMENTS OF EFFICIENCY

Summary. Results of laboratory experiments of a Class DE inverter are presented in the paper. The inverter contains a flyback topology driver connected to the inverter Mosfets via a gate transformer. The following modules of the inverter are described: a control circuit and a Mosfet driver, a half-bridge power circuit and a serial-parallel matching load with 50 Ω resistor. The oscillograms, the results of power measurements and calculations of the efficiency are given. The inverter efficiency was 71% at 450 W the output power equal to 450 W. The possible applications of the inverter are induction or dielectric heating.

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