Saturation Of Magnetic System Research Articles

Synthesizing the Optimal Control of an Induction Motor-Based Traction Electric Drive with Taking into Account Magnetic Saturation and Core Losses

Traction electric drives based on an induction motor often employ vector control with orienting along the rotor flux vector, with which it becomes possible to achieve high performance indicators of the motor and drive as a whole in both static and dynamic operation modes. However, to achieve high energy efficiency of the drive, the use of optimal control strategies becomes of issue. This implies the need to set up, given a specified electromagnetic torque, the stator current flux-forming and torque-forming components according to a certain law to achieve the motor operation optimized with respect to the selected criterion. In the context of a traction electric drive, such criteria are stator current to be maximized or power losses to be minimized. In doing so, it is important to take into account the motor magnetic system saturation and core losses, which have a significant impact on the synthesis of optimal control strategies. The article gives the equations of electromagnetic processes in a cage induction motor with field-oriented control and with taking into account the above-mentioned specific features. A procedure for synthesizing optimal control strategies while minimizing power losses and stator current is also given. Differences in approaches to the synthesis of optimal strategies with and without taking the magnetic system saturation into account are shown.

Оценка бросков тока намагничивания силового трансформатора

The mathematical model of a shell-core power transformer’s magnetization branch is substantiated. By using the model, analytical expressions for the magnetizing current instantaneous values under the conditions of geomagnetic disturbances can be obtained. Quantitative assessments of the magnetizing inrush current amplitudes and durations versus the geomagnetic disturbance intensity are obtained. The dynamics of the power transformer magnetic system saturation transient and changes in the magnetization inrush current amplitudes and durations after a sudden occurrence of geomagnetic disturbances are shown. The error of estimating the magnetizing inrush current amplitudes under geomagnetic disturbances is determined based on comparison with experimental data.

Модель асинхронного электродвигателя с учетом насыщения его магнитной системы на основе метода Такаги–Сугено

Модель асинхронного электродвигателя с учетом насыщения его магнитной системы на основе метода Такаги–Сугено

ANALYSIS OF THE SPECIAL FEATURES OF THE THERMAL PROCESS IN AN INDUCTION GENERATOR AT HIGH SATURATION OF THE MAGNETIC SYSTEM

Purpose. Development of the method for the assessment of the thermal operation modes of an autonomous electrical power system with an induction motor, aiming at improvement of the reliability of electricity supply and the quality of electric energy. Methodology. Induction generator mathematical modeling taking into account the magnetic system saturation was used in the research. A heat model taking into account the excess of the temperature of the induction generator units in the mode of high saturation was developed. The obtained results were compared with the experimental data. Results. The paper contains the solution to the problem of improvement of the mathematical model sand methods for steel losses determination in there search of the operation modes of an autonomous uncontrolled induction generator taking into consideration the properties of the magnetic system in the mode of high saturation. The expression for determination of steel losses in the mode of high saturation is obtained. It enables the assessment of the induction generator thermal condition. Originality. The analytical dependence for the calculation of the steel losses in the mode of magnetic system saturation has been obtained for the first time. Practical value. The obtained expression for the calculation of the steel losses can be used for determination of the admissible time of generator operation at overload. It will allow avoiding broken winding insulation and complete use of the generator overload capacity. As a result, it will reduce possible irregularities of electricity supply due to the generator preliminary cutoff.

Saturation influence of the induction motor magnetic system on the current spectrum powered by a pulsed voltage source

A model for the study of the fundamental and higher stator current harmonics with a certain magnetic system saturation of the induction motor from form of power supply was proposed. The influence of induction motor magnetization curve non-linearity of the stator current form, powered by the three-phase bridge inverter was analyzed. The method of accounting non-linearity of the magnetization curve in the stator current spectrum analysis was proposed. A result of current spectra for different states of the induction motor was shows. Ref. 11, pic. 3

Amorphous Alloy Cores for HTSC Electrical Devices

The paper describes results of testing of magnetic loss and saturation of magnetic system for superconductive electrical devices, manufactured of AMAG 225 AMAG 170 amorphous alloys produced by the Open Joint-Stock Company “Mstator”. Note that annealing of the cores was not carried out, since previous experience shows that annealing process makes steel crispy, and, furthermore, in case of thermal cycling, which occurs in cryogenic machines and devices, the destructive process is accelerating and results in the total destruction of amorphous tape. Manufacturing of the cores of different superconductive electrical devices requires testing with 2NSR, 5BDSR amorphous alloys, AMAG 200 nanocrystalline tape, (unannealed and annealed). The results of these investigations were published previously.

Basic Statements of Research and Magnetic Field of Axial Excitation Inductor Generator

Basic Statements of Research and Magnetic Field of Axial Excitation Inductor GeneratorIn this work the main features of axial excitation inductor generators are described. Mathematical simulation of a magnetic field is realized by using the finite element method. The objective of this work is to elucidate how single elements shape, geometric dimensions and magnetic saturation of magnetic system affect the main characteristics of the field (magnetic induction, magnetic flux linkage). The main directions of a magnetic system optimization are specified.