Investigation of the electromagnetic compatibility of a frequency-controlled electric drive with supercapacitors

In the paper, the electromagnetic compatibility of a frequency converter with a power supply is investigated. Comparison of the variants of the electric drive with conventional capacitors and supercapacitors, which are connected directly to the DC link of the frequency converter, is given. The simulation results in the MATLAB package and the experimental study of the electric drive with using the power quality analyzer are presented. The paper presents the forms of currents and voltages at the input of the frequency converter, as well as their harmonics composition. Conclusions about the influence of the supercapacitor block on the electromagnetic compatibility of electric drive to the mains are made. © 2018 I.V. Plotnikov and I.S. Uimin.17-08-00188I. V. Plotnikov and I. S. Uimin The reported study was funded by RFBR according to the research project № 17-08-0018

An Indirect Method for Determining the Local Heat Transfer Coefficient of Gas Flows in Pipelines

An indirect method and procedure for determining the local heat transfer coefficient in experimental studies on the intensity of heat transfer at a gas–surface interface is described. The article provides an overview of modern approaches and technical devices for determining the heat flux or friction stresses on surfaces in the study of thermophysical processes. The proposed method uses a constant-temperature hot-wire anemometer and a sensor with a thread sensitive element fixed on the surface of a fluoroplastic substrate. A substrate with the sensor’s sensitive element was mounted flush with the wall of the investigated pipeline. This method is based on the Kutateladze–Leontiev approach (the laws of friction and heat transfer) and the hydrodynamic analogy of heat transfer (the Reynolds analogy): this is an assumption about the unity of momentum and heat transfer in a turbulent flow, which establishes a quantitative relationship between friction stresses on the heat exchange surface and heat transfer through this surface. The article presents a method for determining the speed of the developed measuring system. An example of a successful application of the proposed method in relation to the study of thermomechanical processes in the gas exchange systems of reciprocating internal combustion engines is described. © 2022 by the authors.Ministry of Education and Science of the Russian Federation, MinobrnaukaThe research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program) is gratefully acknowledged

Investigation of parameters variation of speed controller on the frequency responses in vector automatic control system

The article considers the method of adjusting the frequency converter on preset quality parameters of transients. Regulation is carried out by means of changing the parameters of proportional-integral speed controller at constant performance of closed-loop current controller. Influence of parameters the proportional-integral speed controller on frequency response of vector control system is shown. Results of the simulation and experimental investigations based on the frequency converter Siemens Sinamics S120 are given. Recommendations for adjust settings of closed-loop speed controller of the vector control system at different performance are proposed as a conclusion.В статье рассматривается методика настройки преобразователя частоты на заданные показатели качества переходного процесса. Регулирование происходит за счет изменения параметров пропорционально интегрального регулятора скорости при неизменном быстродействии контура тока. Показано влияние параметров ПИ регулятора скорости на частотные характеристики векторной системы управления и показатели качества переходных процессов. Приводятся результаты моделирования и экспериментальных исследований на базе преобразователя частоты Siemens Sinamics S120. В качестве вывода предложены рекомендации для настройки контура скорости векторных систем управления с различным быстродействием

Selection of power module and development of the circuits for frequency-controlled electric drive with microprocessor control system

This article is devoted to the creation of a test bench for the study of algorithms and control systems for frequency-controlled electric drive with microprocessor control based on the digital signal processor TMS320F28335. The requirements for choosing of the power module are formulated. The development of circuits for adaptation of logic signals levels is described.В данной статье представлена работа по созданию испытательного стенда для изучения алгоритмов и систем управления частотно-регулируемым электроприводом с микропроцессорным управлением на базе цифрового сигнального процессора TMS320F28335. Рассматриваются требования к выбору силовой части. Проводится разработка схем для согласования уровней логических сигналов

Choice of parameters and stability of nonlinear vibration isolation device

Work of active vibration isolation devices with single-mass electromagnetic suspension taking into account of real characteristics of the voltage regulators is described. The analytical researches are carried out; the areas of stability of work of nonlinear vibration isolation device are defined

Inhomogeneous boundary value problems for compressible Navier-Stokes equation: well-posedness and sensitivity analysis

In the paper compressible, stationary Navier-Stokes equations are considered. A framework for analysis of such equations is established. In particular, the well-posedness for inhomogeneous boundary value problems of elliptic-hyperbolic type is shown. Analysis is performed for small perturbations of the so-called approximate solutions, i.e., the solutions take form (1.12). The approximate solutions are determined from Stokes problem (1.11). The small perturbations are given by solutions to (1.13). The uniqueness of solutions for problem (1.13) is proved, and in addition, the differentiability of solutions with respect to the coefficients of differential operators in shown. The results on the well-posedness of nonlinear problem are interesting on its own, and are used to obtain the shape differentiability of the drag functional for incompressible Navier-Stokes equations. The shape gradient of the drag functional is derived in the classical and useful for computations form, an appropriate adjoint state is introduced to this end. The shape derivatives of solutions to the Navier-Stokes equations are given by smooth functions, however the shape differentiability is shown in a weak norm. The method of analysis proposed in the paper is general, and can be used to establish the well-posedness for distributed and boundary control problems a well as for inverse problems in the case of the state equations in the form of compressible Navier-Stokes equations. The differentiability of solutions to the Navier-Stokes equations with respect to the date leads to the first order necessary conditions for a broad class of optimization problems

Inhomogeneous boundary value problems for compressible Navier-Stokes and transport equations

In the paper compressible, stationary Navier-Stokes eqautions are considered. A framework for analysis of such equations is established. The well-posedness for homogeneous boundary value problems of elliptic-hyperbolic type is shown

Using PWM Output as a Digital-to-Analog Converter

This article presents a method for utilizing the on-chip pulse width modulated (PWM) channels on the TMS320F28335 microprocessor as a digital-to-analog converter (DAC). The article contains a technique for filtering high-frequency analog PWM signals, leaving only low-frequency components. Theoretical and experimental results are presented for the quantitative evaluation of the achieved result.В статье рассматривается способ использования встроенных каналов широтно-импульсной модуляции (ШИМ) на микропроцессоре TMS320F28335 в качестве цифро-аналогового преобразователя (ЦАП). Статья содержит методику фильтрации высокочастотных сигналов ШИМ, которая позволяет выделить полезную составляющую сигнала. Представлены теоретические и экспериментальные результаты для оценки качества фильтрации

Selection of the Electric Drive System for Controlling a Wide Universal Milling Machine 676P

The article deals with the problem of selecting an electric drive system for automatic control of a wide-universal milling machine 676 P. The requirements for an electric drive are described, the selected variant based on stepper motors is considered in detail, a scheme for connecting the system is developed.В научной статье рассматривается задача выбора системы электропривода для автоматического управления широкоуниверсальным фрезерным станком 676 П. Описаны требования к электроприводу, подробно рассматривается выбранный вариант на основе шаговых двигателей, разработана схема подключения системы