Control method, especially for load balancing of a plurality of electromotor drives
AssigneeSMS Schloemann-Siemag Aktiengesellschaft
InventorsThorsten Bode, Jurgen Bernhardt
Life of this patent
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Abstract
A load-balancing method for a multiplicity of controlled drives, especially individual electric motors of the rolls of a leveling machine for metal strip, in which all of the motors have speed and current-control circuits and are interconnected by a superordinate memory programmable computer or controller. A respective load-balancing controller, preferably of the PI type, is provided between the computer and the input to the current controller to vary the current setpoint signal supplied to the latter by the speed controller in each system.
Claims14
A method of load-balancing control for a plurality of controlled electromotor drives, comprising the steps of:
- (a) providing for each of said drives a respective speed-control feedback circuit and a respective current-draw feedback control circuit and generating a respective load-responsive parameter in at least one of said circuits indicative of loading of the respective drive;
- (b) monitoring the load-responsive parameters of all of said drives in a hierarchically superordinate controller by comparing the respective load-responsive parameters with a setpoint value of the respective load-responsive parameter assigned to the respective drive and chosen to balance loading of said drives, and generating a corrected parameter for each drive based upon the comparison;
- and
- (c) applying the corrected parameter through a fixed-transfer-function load-compensating controller as an actual-value input to one of the feedback circuits of the respective drive.
A load-balancing control system for a plurality of controlled electromotor drives comprising:
- a respective speed control feedback circuit and a respective current-draw feedback control circuit for each of said drives including means in at least one of said circuits for generating a respective load-responsive parameter indicative of loading of the respective drive;
- a hierarchically superordinate controller receiving the respective load-responsive parameter from all of said drives for comparing the respective load-responsive parameters with setpoint values of the respective load-responsive parameter assigned to the respective drive and choosing the balance loading of said drives, and generating a corrected parameter for each drive based upon the comparison;
- and
- a fixed-transfer-function load-compensating controller connected to said superordinate controller and receiving the respective corrected parameter therefrom for applying the corrected parameter as an actual-value input to one of the feedback circuits of the respective drive.
Dependencies are inferred from the claim text.