Patent ID: 8629634
Filing Date: 2014-01-14
Classification: B60L,H02P,Y02T

Abstract:
1. A method for using pulse-width modulated signals in the control of the electric current drawn from a source of electricity by a system comprising: a single central controller configured to provide synchronized pulse-width modulated (PWM) signals; a motor subsystem chosen from the group consisting of a plurality of electric motors each of which has a single winding; at least one electric motor with multiple windings; and, a plurality of electric motors, at least one of which has multiple windings; in cases in which said motor subsystem comprises a plurality of electric motors: measuring means for measuring the current being drawn by each of said plurality of electric motors; current controlling means for controlling the current being drawn by each of said plurality of electric motors; in cases in which said motor subsystem comprises at least one motor with multiple windings: measuring means for measuring the current being drawn by each of said windings; current controlling means for controlling the current being drawn by each of said windings; and, transmitting means for transferring signals between said central controller and said current controlling means; wherein said method comprises: in cases in which said motor subsystem comprises motors with single windings, measuring separately current being drawn by each of said electric motors with a single winding; in cases in which said motor subsystem comprises motors with multiple windings, measuring separately current being drawn by each winding of said motors with multiple windings; transmitting to said central controller, according to a predetermined sequence, a plurality of signals, each one of said plurality of signals corresponding to the current being drawn by one of said of motors with a single winding or to the current being drawn by one of the windings of each of said motors with multiple windings; transmitting, according to a predetermined sequence, at least one PWM signal from said central controller to each of said current controlling means, each of said at least one PWM signal corresponding to the amount of current to be drawn by said motor or said winding, whereby the relative phases and durations of said at least one PWM signals are distributed according to a predetermined protocol; and, repeating the previous three steps while said motors are in operation; whereby the distribution of PWM signals defines the total current drawn from said source of electricity as a function of time.