Acoustic noise from small electronically commutated motors

An analysis of acoustic noise in electronically controlled variable speed drives is presented. The causes of vibration and acoustic noise in switched reluctance motors are discussed and it is shown that brushless d.c. motors can produce resonant vibration and acoustic noise by similar mechanisms. The flux switching motor is introduced. This new class of reluctance motor is an advance on the established switched reluctance motor, retaining many of its benefits, but with a simpler and cheaper power electronic converter. The phase windings and method of flux control are different and tests are performed to quantify the effect on the acoustic noise produced. Measurements of acoustic noise are made on one flux switching motor and one 2-phase switched reluctance motor, made from the same laminations and mechanical components. It is shown that the flux switching motor produced 2dB less acoustic noise under the same conditions. Finite element analysis is used to calculate the radical force profiles of the two motors during normal rotation, and further analysis of this data provides evidence to support the experimental results. The experimental results go on to show how the acoustic noise from a second flux switching drive was found to be comparable to that of a split phase induction motor

Proceedings of the 10th international conference on energy efficiency in motor driven systems (EEMODS' 2017)

The 10th International Conference on Energy Efficiency in Motor Driven Systems (EEMODS'17) was be held in Rome (Italy) on 6-8 September, 2017. The EEMODS conferences have been very successful in attracting distinguished and international presenters and attendees. The wide variety of stakeholders has included professionals involved in manufacturing, marketing, and promotion of energy efficient motors and motor driven systems and representatives from research labs, academia, and public policy. EEMODS’15 provided a forum to discuss and debate the latest developments in the impacts of electrical motor systems (advanced motors and drives, compressors, pumps, and fans) on energy and the environment, the policies and programmes adopted and planned, and the technical and commercial advances made in the dissemination and penetration of energy-efficient motor systems. In addition EEMODS covered also energy management in organizations, international harmonization of test method and financing of energy efficiency in motor systems. The Book of Proceedings contains the peer reviewed paper that have been presented at the conference.JRC.C.2-Energy Efficiency and Renewable

Bibliography of Lewis Research Center Technical Publications announced in 1991

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific engineering work performed and managed by the Lewis Research Center in 1991. All the publications were announced in the 1991 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology