METHOD AND MEANS FOR MEASURING THE TEMPERATURE OF THE POLE WINDINGS OF THE ELECTRIC MACHINE ROTOR

The temperature of the pole windings is one of the main informative parameters, the deviation of which may indicate the presence of a number of common defects of electrical machines. However, the implementation of high-precision means for measuring the temperature of the pole windings of the electric machine rotor is associated with a number of technical difficulties. The aim is to increase the accuracy of measuring the temperature of the pole windings of the rotor of an electric machine by developing a contactless method and means of measuring the temperature of the pole windings of the rotor in real time. The paper shows that the existing most common methods of temperature measurement have significant disadvantages that limit the possibility of their use for the implementation of means of measuring the pole windings of the rotor of an electric machine. A bispectral pyrometric method of temperature measurement is proposed, which provides simultaneous conversion into voltage of functionally temperature-dependent spectral densities of radiation for two spectrally close electromagnetic waves with subsequent finding of their ratio, which allowed to remove the most significant components of methodical measurement characteristic of classical pyrometers. The design of the bispectral pyrometric measuring system of temperature of pole windings of a rotor of rotating electric machines realized on the basis of the offered method of measurement, suitable for work in a real-time mode together with systems of control of a technical condition and diagnostics is developed.

Modeling and Calculating Vibration Characteristic of Car Body Assembled and Manufactured in Vietnam

In recently years, Automotive industry in Vietnam is a fast growing sector, mainly reliant on domestic produces, assembly and sales. There are some details of cars that have been modeled, calculated to research and fabricate. Body vibration of the vehicles is one of the criteria to evaluate quality in the process of manufacturing and assembling automobiles. There are so many factors affecting on vibration of vehicles, in that body structure is one of the main causes. Up to now, automobiles manufactured and assembled in Vietnam have not yet had specific evaluations and standards on vibration. Determination of characteristic body vibration is a main part to reduce sound and vibration. In this paper, the modelling and calculating the body’s characteristic vibration of cars manufactured, assembled in Vietnam was researched. The body structure is designed by 3D model using commercial Catia Software. The model was transformed from Catia software to Hypermesh software, using finite element method to simulate. The calculation results of 25 measurement characteristic vibrations whose frequency is in range of 22.77 Hz to 97.21 Hz. The results are shown that, characteristic vibration of state 1 and 2 significantly influence the noise of the body. This is also the basis for optimal analysis of the body structure to control the vibration and noise of automobiles.

The analog linearization of Pt100 working characteristic

The most exact temperature measurement can be made by using platinum sensors. Temperatures from -254.3?C up to +850?C can be measured with Pt100 sensor. The relationship between resistance and temperature is relatively linear, but for measurements of very high precision, Pt100 working curve should be a little bit improved. The paper describes an efficient way of measurement characteristic linearization by using the analogue electric circuits. The obtained results proved the initial considerations and the Pt100 becomes rather transducer than pure sensor.

Field Experience with the Lambert “Twin” Tower at the Geodetic Survey of Canada

A new survey tower, which combines the provision for precise angle measurement, characteristic of wooden and steel structures, with the mobility and ease of assembly of lightweight aluminum structures, was tested under field conditions to establish its viability for use on first-order horizontal control surveys. Constructive criticism from the user and cooperation from the manufacturer combined to produce a survey tower that can be used to advantage in the variety of field conditions encountered on conventional type control surveys.