G. S. Brown

Synchronous-motor pulling-into-step phenomena

INVESTIGATIONS of synchronous motor phenomena during transient conditions have been made, using a mechanical calculating machine called the “differential analyzer” to solve the non-linear differential equations involved. Previous investigations have been made on a preliminary calculating machine called the “product integraph.” The extent and accuracy of the solutions, however, were limited on this preliminary machine, and the work was confined principally to determining whether or not a synchronous motor would synchronize for the worst switching conditions. The curves presented in the present paper and obtained by use of the differential analyzer make it possible to calculate quantitatively the additional load that may be synchronized if the field switch is closed at the most favorable switching angle.

Educating electrical engineers to exploit science

Are the future electrical engineers being trained broadly enough in the sciences? This question has been given serious study at the Massachusetts Institute of Technology, with the result that major changes have been made in the undergraduate electrical curriculum, so as to better equip the students with technical substance and professional vision.

Synchronous-Motor Pulling-Into-Step Phenomena Mathematical Solutions of Various Idealized Differential Equations of Motion Made Upon the Differential Analyzer

The Differential Analyzer at the Massachusetts Institute of Technology has made possible the rapid and accurate solution of the idealized non-linear differential equations of motion of synchronous motors which describe the pulling-into-step transients. The purpose of this paper is to present the results of these solutions in a useable form. These results give a rather complete analysis of the phenomena, and thus enable the determination of the performance of practically any machine. One of the factors which is considered in this paper is the time constant of the field circuit with the armature short-circuited. Curves are given showing the additional load which may be synchronized when the field switching is angularly controlled to the best angle. The influence of salient poles has been considered as well as non-uniformity of the amortisseur winding. The practical application of the study is indicated by a numerical example.

Today's Dilemma in Engineering Education

The present wide-scale activity to increase the science content of engineering curricula can, if not skillfully accomplished, result in the teaching of science, and not the engineering of science, to engineers. The changes experienced in the substance of the curricula are sometimes so great that faculties encounter great difficulty in providing worthwhile engineering examples to support their presentations of engineering science.

Integration versus options in electrical engineering

With the growth of electrical engineering and the introduction of options in engineering education, the electric power field lost much of its popularity with students to the more glamorous communications and electronics curricula. To compensate for this trend, the universities must establish a creative environment for study of energy conversion and utilization subjects.

A new educational program in energy conversion

The energy-conversion portion of the new electrical engineering curriculum at Massachusetts Institute of Technology is described. The motivation for the curriculum revision is to equip engineers with adequate electrical science to contribute to the advancement of electrical technology in any industry, not merely those normally thought of as electrical.

Pulling-into-step equations solved

By means of the “differential analyzer,” the equations describing the pulling-into-step transients of a synchronous motor can be solved readily and accurately. The results of such solutions give a rather complete analysis of pulling-into-step phenomena, and thus make possible the determination of the performance of practically any synchronous motor. Practical application of the study is illustrated by a numerical example.

Closing the Engineering Gap: One Approach

In the national debate about the shortage of people trained to advanced levels in modern technology, have we not overlooked the engineer already in practice? If the knowledge and skill of selected, key, practicing engineers were updated and reoriented, these men could help greatly to close the gap. As the pace of scientific advance continues, the knowledge of engineers who have been out of school for a number of years lags more and more. It appears that the quickest and perhaps the best way to fill the gap in numbers and capability, in both industry and education, is to embark on a formal program of updating and reorienting the skills of the most promising men now in these two fields. The character of the gap is well illustrated by the observations that during the 1945-1950 period few undergraduate engineering curricula included the fundamentals of nuclear physics, feedback control, information theory, digital computer technology, solid-state physics and molecular engineering, plasma physics, interactions of electromagnetic theory with fluid dynamics and statistical and wave mechanics, probability theory in decision making, relativity theory, or modern mathematics. The demands now imposed by the nations space effort were not even visualized. There are three major groups-engineering managers, technical group leaders, and engineering professors-that seek assistance. Most attempts to solve the crucial problem of updating our engineers are fragmented, or lacking in certain key elements.

An Amplifier-Wattmeter Combination for the Accurate Measurement of Watts and Vars

As part of a program of improvements made to the network analyzer in the electrical-engineering research laboratory at the Massachusetts Institute of Technology, an instrument to measure watts and vars has been devised which imposes a negligible burden upon the network, is rapid in response, and has an error less than one-half per cent of full scale. The instrument consists of (1) a semistock electrodynamic wattmeter, (2) a negative-feedback vacuum-tube amplifier, and (3) a phase-shifting network. When the equipment is once assembled the presence of the amplifier may be ignored and the instrument used thereafter as any portable instrument. The principle of instruments of this kind has other important applications in the field of electrical measurements.

Closing the engineering Gap

Narrowing the gap between our rapidly advancing knowledge and current practice is essential, but will take years. Perhaps the quickest and most effective way of achieving this goal is to embark on a formal program of updating and reorienting the skills of the most promising men now active in the fields of industry and education