The choice of an induction motor drive of the fan of the locomotive with a condition to ensure its steady work

В работе рассмотрены вопросы обеспечения устойчивой работы асинхронного двигателя для привода вспомогательных систем (вентилятора) тепловоза, напряжение к которому подается от тягового генератора. Определены параметры двигателей вентиляторов, наиболее устойчивых при работе от напряжения, величина и частота которого зависят от скорости движения железнодорожного состава. При выборе двигателя и режимов управления учитывались требования энергосбережения во всем диапазоне его эксплуатации.Розглянуто питання забезпечення стійкої роботи асинхронного двигуна для приводу допоміжних систем (вентиляторів) тепловоза, напруга до якого подається від тягового генератора. Визначено параметри двигунів вентиляторів, найбільш стійких при роботі від напруги, величина і частота якої залежать від швидкості руху залізничного потягу. При виборі двигуна і режимів управління враховувалися вимоги енергозбереження у всьому діапазоні експлуатації.The paper deals the problems of ensuring stable operation of an induction motor for driving the auxiliary systems (the fans) of the diesel locomotive, the voltage which is supplied from the traction generator. Are defined the parameters of the fan motors, the most stable when working with tension, the magnitude and frequency of which depend on the speed of the train are defined. When selecting a motor and the control modes were taken into account the requirements of energy conservation during an all operating range

The DC-SQUID-based Magnetocardiographic Systems for Clinical Use

AbstractThe new line of dc-SQUID-based magnetocardiographic (MCG) systems (named as the “MAG-SCAN”-family) is designed, fabricated and tested. These systems are intended for routine MCG investigations of patients at conditions of real clinical electrophysiological labs. The “MAG-SCAN”-family includes the line of MCG devices compatible in terms of hardware and software with number of measuring channels from 1 to 36. Experimental prototypes of 7- and 9-channel MCG-systems (the models “MAG-SCAN-07” and “MAG-SCAN-09” fabricated at CRYOTON Co. Ltd.) were installed in a few hospitals of Moscow city and operated in an unshielded environment of usual clinical labs. Well balanced second-order gradiometers have been used for MCG data recording. They demonstrated an intrinsic noise level better than 5 fT/√Hz. The total noise level of about 20-40 fT/√Hz was measured at urban conditions of Moscow city. The package of special software (named as the “SOFTMAG”) was developed as two autonomous subsystems that allow the preprocessing of the heart magnetic signals and the spatio-temporal analysis of the field characteristics and the field sources. The software employs the algorithms for the analysis and estimation of the spatio-temporal characteristics of the heart magnetic field and the correspondent electrical currents distributions. More than 2000 investigations of different volunteers including healthy persons, patients with high blood-pressure, ischemic disease (IHD), chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA) were carried out and sets of MCG-parameters specific for each group were found