Alexander Kusko

Application of Static Uninterruptible Power Systems to Computer Loads

Reliable operation of on-line computers requires an uninterruptible source of electric power; some computers are sensitive to power interruptions as short as one half-cycle of line frequency. Two static-type uninterruptible power systems that have been purchased by the Federal Aviation Administration for installation at air route traffic control centers are described. One, built by the General Electric Company, represents commercial design and construction; the second, built by the Garrett Corporation, represents design and construction to comply with the Federal Aviation Administration specification prepared for uninterruptible power system equipment.

A unified approach to the teaching of electromechanical energy conversion

This approach presents a consistent treatment of electromechanical-energy conversion using the theory of circuits and fields in relative motion. The approach is an attempt to produce an acceptable solution to present-day electrical engineering curricula.

Quality of Electric Power

Defects in the quality of electric power supplied to modem loads such as computers and logic-control systems produce expensive and dangerous errors and failures. Defects can be categorized by magnitude and time duration, but information on occurrence in typical utility systems is lacking and quantitive means for description must be developed. The impact on critical loads can be reduced by improvements in utility system design, by increasing the load equipment tolerance, and by using rotating and static standby units between the source and the load.

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.

Experimental Characteristics of the 3-Phase Polyunit Saturable Reactor [includes discussion]

The design and operating characteristics of an experimental 2.7-kva 12-unit 3-phase polyunit saturable reactor are described. Experimental results show that the load current wave form is practically sinusoidal over all regions of operation in accordance with the design objective. 27, 1995.

Computer for automatizing network analyzers

THE RECENT ACTIVITY AND INTEREST in the development of computer methods for speeding up the solution of power-system transient-stability problems has prompted the reporting of some work done to accomplish this task on the Massachusetts Institute of Technology (MIT) Network Analyzer.

Regulators Using Hall-Effect Devices for Multiplier Sensors

In the design of regulators it is desirable that the quantity to be regulated should be sensed directly in the form most nearly corresponding to the regulated quantity. The Hall-effect device is a sensor which provides an output voltage proportional to the instantaneous product of a magnetic field in one axis, and a current in the second axis and, hence, makes possible the direct sensing of the product of any two quantities that can be converted to currents.

Thermal considerations of generators in high-speed aircraft

The problem of providing effective cooling of electric power equipment in aircraft becomes more acute as flight speeds and altitudes increase. Present trends in generator design are to introduce new high-temperature materials, to employ a circulating coolant and an external heat exchanger, and to depend upon the evaporation of liquids for cooling.

Magnetic-amplifier control of D-C motors

ALTHOUGH considerable work has been done on the operation of adjustable-speed d-c motors with armature power supplied by thyratrons1 and by metallic rectifiers controlled with adjustable transformers,2,3 there is little information available on the use of magnetic amplifiers for this purpose. For this reason, an analytical and experimental study was made of the steady-state operation of a d-c motor with armature power supplied through metallic rectifiers and controlled by saturable reactors or magnetic amplifiers. More specifically, the speed-torque characteristics of the motor were determined for the various control methods and, in particular, the effectiveness of simple feedback connections and the use of external armature-circuit inductance was ascertained in improving the speed regulation.