The Maintenance of Fractional Degree Phasing Between Two Separate AC Voltages or Rotating Shafts
Abstract
A method is often required whereby two or more sources of electrical potential may be automatically maintained not only in frequency synchronism but also in phase synchronism to a very high degree of accuracy. Occasionally, the same high degree of phase accuracy must be maintained between the instantaneous shaft positions of two or more rapidly rotating devices such as electric motors. A system has been developed that is useful in fulfilling both of these requirements. It consists essentially of treating the problem on a master and slave basis whereby the voltage of the one or more slave sources of potential is maintained under continuous phase comparison with that of the master. When any small phase change develops, an error signal is produced that actuates a servo system, automatically correcting the phase of the slave station. For the maintenance of mechanical phase alignment, the shaft positions of the master and slave devices are translated into AC electrical potentials whose phases are compared in a similar system, and any necessary correction effected through a servomechanism. Performance data indicate that phase accuracy to plus or minus one minute of electrical or mechanical phase difference can be obtained.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 29, 1957
- Accession Number
- AD1224486
Entities
People
- S. F. Johnson
Organizations
- United States Naval Research Laboratory