Electricity: motive power systems – Plural – diverse or diversely controlled electric motors – Load control
Patent
1991-11-19
1993-05-11
Wysocki, Jonathan
Electricity: motive power systems
Plural, diverse or diversely controlled electric motors
Load control
318432, 318 63, H02P 700
Patent
active
052104737
ABSTRACT:
The invention is an improvement in an AC adjustable frequency load-moving system of the type having a control circuit providing a motor speed signal and using command ramps to control each of plural AC squirrel cage motors. The invention helps assure substantially equal load sharing by the motors. The improvement includes a dwell circuit which maintains the motor speed reference signal at a synchronizing value at least for a period of time denominated as the dwell time. This permits microprocessors--which may be running asynchronously--to both "read" the same value of motor speed signal even though such value may be read at slightly different instants. Separate inverter units monitor such signal and responsively generate synchronized command ramps to effect load sharing. The invention is suitable for use with a wide variety of plural-motor drive systems and has been found to be particularly suitable for use on crane hoist systems.
REFERENCES:
patent: 3845366 (1974-10-01), Metzler et al.
patent: 4166238 (1979-08-01), Binner
patent: 4267493 (1981-05-01), Roof
patent: 4408281 (1983-10-01), Tack, Jr. et al.
patent: 4658971 (1987-04-01), Kornely
patent: 4765456 (1988-08-01), Bower
patent: 5077508 (1991-12-01), Wycoff et al.
patent: 5086964 (1992-02-01), Blaser
Harnischfeger Corporation
Wysocki Jonathan
LandOfFree
System with delay timer for motor load equalization does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System with delay timer for motor load equalization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System with delay timer for motor load equalization will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1353519