Westinghouse Electric

About: Westinghouse Electric is a company organization based out in Cranberry Township, Pennsylvania, United States. It is known for research contribution in the topics: Brake & Signal. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

Pulsewidth Modulated Inverter Motor Drives with Improved Modulation

Abstract: The performance of inverter drives, which use the pulsewidth modulated (PWM) technique to control motor applied voltage and frequency, are critically influenced by the choice of the modulation policy used in the control circuits. This paper deals with practical inverter drives for squirrel cage induction motors and presents some basic considerations on modulation requirements. The advantages and limitations of popular modulation methods are discussed, and an improved modulation scheme, which allows us to extend the practical speed range of PWM ac drives, is presented.

Some results on operator performance in emergency events

Abstract: This paper synthesizes results from several studies of operator performance in simulated power plant emergencies and from retrospective analyses of operator performance in five actual power plant critical incidents. This synthesis is feasible because all of these studies used process tracing techniques and a common perspective on decision making as the basis for their analysis of operator performance. The paper focuses on two areas: operator's ability to detect and correct errors and how operators utilize procedures. The results in these areas are assessed in terms of their implications for concepts and models relevant to operator performance and in terms of their implications for man-machine system improvements.

Uninterruptible power supply system and load transfer static switch for such a system

Abstract: A UPS system which operates initially in a commutation mode allowing commutation of the static transfer switch provided on the primary supply lines, and wherein the standby source is kept energized so as to operate to commutate such transfer switch through the inverter just before initiating UPS mode of operation.

Object identifying apparatus

Abstract: An object-identifying label having printed on a throw-away flexible substrate an identifying electrical circuit and moved with the object through a region where the identifying circuit is read. Typically, the object is a mail sack or baggage which is to be directed along a predetermined path. When the object moves through the region, the label is randomly positioned in the region. A substantially homogeneous electromagnetic field is produced in the region and as the object moves through the region, the circuit on the label is powered only by, and reacts with, the field, absorbing energy from the field.