Apparatus and methods for controlling induction motors

Electricity: motive power systems – Induction motor systems – Power-factor control

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

318778, 318798, 318812, H02P 540

Patent

active

048003263

ABSTRACT:
When induction motors are lightly loaded their power factors and efficiency are poor but in the present invention power factor is controlled regardless of load. An induction motor is connected by way of a triac to a supply. The voltage across the triac is monitored by a comparator for voltage steps which correspond to current turn-off and a signal is developed at the output of an amplifier which represents error from required phase lag. A further comparator and a trigger pulse generator trigger the triac in accordance with the error. An override circuit overrides the control system during starting. A number of further induction motors may be connected in parallel with the motor. Additional circuits deal with problems arising when a three-phase induction motor is connected by three wires only.

REFERENCES:
patent: 3441823 (1969-04-01), Schlabach
patent: 3652924 (1972-03-01), Dieterich et al.
patent: 4052648 (1977-10-01), Nola
patent: 4176307 (1979-11-01), Parker
patent: 4190793 (1980-02-01), Parker et al.
patent: 4242625 (1980-12-01), Hedges
patent: 4243926 (1981-01-01), Phillips
patent: 4266177 (1981-05-01), Nola
patent: 4297628 (1981-10-01), Hedges
patent: 4298834 (1981-11-01), Opfer
patent: 4333046 (1982-06-01), Lee
patent: 4338557 (1982-07-01), Wanlass
patent: 4355274 (1982-10-01), Bourbeau
patent: 4361793 (1982-11-01), Nordell
patent: 4369403 (1983-01-01), Lee
patent: 4379986 (1983-04-01), Baxter et al.
patent: 4384243 (1983-05-01), Muskovac
patent: 4387329 (1983-07-01), Harlow
patent: 4388578 (1983-06-01), Green et al.
patent: 4433276 (1984-02-01), Nola
patent: 4469998 (1984-09-01), Nola
NASA Tech. Briefs, Summer 1980, vol. 5, No. 2, MFS 25323.
NASA Tech Brief No. MFS-23280 Apr. 1979.
Frank J. Nola, Improved Power-Factor Controller, Technical Support Package Summer 1980, NASA Tech. Briefs, vol. 5, No. 2, 3 pages of Tech Briefs, pp. 1-7.
Frank J. Nola, Fast-Response Power Saver for Induction Motors, NASA Tech Briefs, Spring 1979, pp. 10 and 11.
Frank J. Nola, Save Power in AC Induction Motors, NASA Tech Briefs, Summer 1977, pp. 8 and 9.
Elektor, pp. 1139-1141 (Nov. 1980) No. 11, vol. 7, Cantebury, Great Britain.
IEEE Transactions on Power Apparatus and Systems, vol. PAS-99, No. 4, Jul./Aug. 1980.
Elektrotechnische Zeitschrift, p. 1397 (Nov. 1979) vol. 100, No. 24.
Energy User News, "Stability Solution Claimed for Some PF Controllers," Sep. 8, 1980.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Apparatus and methods for controlling induction motors does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus and methods for controlling induction motors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and methods for controlling induction motors will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-420803

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.