ІНКРЕМЕНТНИЙ ЦИФРОВИЙ КВАЗІІДЕАЛ ІНТЕГРАТОР ЗАЯВКИ ПОПЕРЕДНЬОГО ПОТОКУ ОЦІНКИ КЕРУЮЧОЇ ІНДУКЦІЙНОЇ МАШИНИ

The performance of the speed controlled induction machine principally depends on the accuracy of the estimated flux. The proposed method compensates the error produced by the inherent problem in the “pure” integrator and measurement error. This paper describes the problem associated with a quasi-ideal digital integrator in particularly a modern DDA-type (Digital Differential Analyzer) – an incremental digital integrator (IDI). The paper essentially discusses the development of the approach to the total error correction of DDA-type IDI. It is an element for processing incremental digital input-output signals using DDA principles. The basic types of errors of the incremental digital integrator are presented and then the reasons for their appearance are examined. The differential equation dY=aYdx as an example the quantitative relation of errors is investigated. The IDI error from the analytical solution is not exceeding one increment (quant) of sub-integral function Y even during a very long interval of integration variable x. This means that the IDI becomes a practically ideal integrator. The suggested methods of correcting IDI errors can be applied in simulation, modeling, especially for dynamic systems control, etc. This method is easily applied in a DSP based induction machine control to estimate the flux.The performance of the speed controlled induction machine principally depends on the accuracy of the estimated flux. The proposed method compensates the error produced by the inherent problem in the “pure” integrator and measurement error. This paper describes the problem associated with a quasi-ideal digital integrator in particularly a modern DDA-type (Digital DifferentialAnalyzer) – an incremental digital integrator (IDI). The paper essentially discusses the development of the approach to the total error correction of DDA-type IDI. It is an element for processing incremental digital input-output signals using DDA principles. The basic types of errors of the incremental digital integrator are presented and then the reasons for their appearance are examined. The differential equation dY=aYdx as an example the quantitative relation of errors is investigated. The IDI error from the analytical solution is not exceeding one increment (quant) of sub-integral function Y even during a very long interval of integration variable x. This means that the IDI becomes a practically ideal integrator. The suggested methods of correcting IDI errors can be applied in simulation, modeling, especially for dynamic systems control, etc. This method is easily applied in a DSP based induction machine control to estimate the flux

Incremental digital quasi-ideal integrator application for advance flux estimation of controled induction machine

The performance of the speed controlled induction machine principally depends on the accuracy of the estimated flux. The proposed method compensates the error produced by the inherent problem in the “pure” integrator and measurement error. This paper describes the problem associated with a quasi-ideal digital integrator in particularly a modern DDA-type (Digital Differential Analyzer) – an incremental digital integrator (IDI). The paper essentially discusses the development of the approach to the total error correction of DDA-type IDI. It is an element for processing incremental digital input-output signals using DDA principles. The basic types of errors of the incremental digital integrator are presented and then the reasons for their appearance are examined. The differential equation dY=aYdx as an example the quantitative relation of errors is investigated. The IDI error from the analytical solution is not exceeding one increment (quant) of sub-integral function Y even during a very long interval of integration variable x. This means that the IDI becomes a practically ideal integrator. The suggested methods of correcting IDI errors can be applied in simulation, modeling, especially for dynamic systems control, etc. This method is easily applied in a DSP based induction machine control to estimate the flux.Эффективность управления скоростью индукционной машины (ИМ – асинхронной машины) преимущественно зависит от точности измерения текущего значения её магнитного потока. Данная статья развивает проблему, связанную с квази-идеальным цифровым интегратором в форме современного цифрового дифференциального анализатора (ЦДА) – инкементнего цифрового интегратора ИЦИ. Предложенный метод компенсирует общую погрешность, возникающую собственно в "чистом" интеграторе и в результате ошибки измерения. В работе подробно рассматривается разработка метода полного исправления (коррекции) погрешности ИЦИ типа цифрового дифференциального анализатора. ИЦИ это – элемент для обработки цифровых сигналов ввода-вывода, используя принцип ЦДА. В первую очередь представлены основные типы погрешностей ИЦИ, а также исследованы причины их появления. Исследовано типовое дифференциальное уравнение dY=aYdx, как пример для анализа количественного соотношения погрешностей. Погрешность ИЦИ по сравнению с аналитическим решением не превышает одного кванта подинтегральной функции Y даже для очень длинного интервала интегрирования переменной x. Это означает, что ИЦИ становится фактически идеальным интегратором. Предложенные методы коррекции погрешностей ИЦИ могут быть применены в имитации, моделировании, и особенно для управления динамическими системами, и т.д. Этот метод легко применим в устройствах управления скоростью индукционной машины основанных на косвенном способе измерении магнитного потока машины

Computer-assisted Electrodynamic Modeling System for Oil and Gas Industry Electric Drives Study

Electrodynamics models of the oil and gas equipment that mainly consist of several controlled electric drives mechanisms and autonomous generators are considered. Applications of the model to drilling and pumping drives are presented.Рассмотрены электродинамические модели автоматизированного нефтяного и газового оборудования, состоящие преимущественно из управляемых электрических механизмов и автономных генераторов. Приведены примеры использования моделей для буровых и насосных установок.Розглянуто електродинамічні моделі автоматизованого нафтового і газового обладнання, які складаються переважно з керованих електричних механізмів і автономних генераторів. Наведено приклади використання моделей для бурових та насосних установок

Controlling exchange bias in Fe3O4/FeO composite particles prepared by pulsed laser irradiation

Spherical iron oxide nanocomposite particles composed of magnetite and wustite have been successfully synthesized using a novel method of pulsed laser irradiation in ethyl acetate. Both the size and the composition of nanocomposite particles are controlled by laser irradiation condition. Through tuning the laser fluence, the Fe3O4/FeO phase ratio can be precisely controlled, and the magnetic properties of final products can also be regulated. This work presents a successful example of the fabrication of ferro (ferri) (FM)/antiferromagnetic (AFM) systems with high chemical stability. The results show this novel simple method as widely extendable to various FM/AFM nanocomposite systems

The risk to develop tuberculosis and efficacy of its preventive treatment in labor migrants residing in the Republic of Tajikistan

Objective: to study the prevalence of latent tuberculosis infection (LTBI), risk factors for LTBI to develop into active tuberculosis, the efficacy of preventive treatment in those with LTBI among labor migrants, residing in the Republic of Tajikistan.Subjects and methods. In the Republic of Tajikistan, 500 residents were followed up as Main Group, they all were labor migrants for more than 3 months and returned to their homeland within one year before inclusion in this study. All of them participated in a questionnaire survey to identify risk factors for developing tuberculosis and had the examination that included Mantoux test with 2 TE and chest X-ray. Comparison Group (CG) consisted of 500 citizens of compatible gender and age who did not travel as labor migrants; they all participated in the same survey and had the same examination.Results. The positive results of Mantoux test with no abnormalities on X-ray were observed in 40% of people in Main Group and 33.4% of people in Comparison Group.The following factors were found to be more frequent in Main Group versus Comparison Group, respectively: frequent and continuous exposure to a TB case – 78.2 and 23.1% (p < 0.01); no tuberculosis prevention – 83.1% and 48.4% (p < 0.01); poor accommodation and work conditions 87.9 and 13.6% (p < 0.01); inadequate diet and lack of proper clothes – 79.4 and 24.3% (p < 0.01); limited access to medical care – 85.4 and 22.6% (p < 0.01). MG was found to have a higher summarized risk coefficient (r = 4.75) versus CG (r = 2.0), p < 0.01. During 2–3-year follow-up of those with LTBI who had no preventive treatment with isoniazod, tuberculosis was diagnosed in 44.4% of people from MG and 18.5% of people from CG. The introduction of the integrated approach to tuberculosis control among people preparing for labor migration allowed reducing the proportion (from 19.7 to 13.7%) of labor migrants in the structure of TB incidence