Patent ID: 9461565
Filing Date: 2016-10-04
CPC Classification: G01R,H02P

Claim Text:
1. A system for starting an alternating current (AC) motor, comprising: a variable frequency drive configured to be coupled to a utility power source and to provide an output voltage having a variable frequency and a variable peak magnitude, wherein the utility power source provides 3-phase power; an AC motor having a rated voltage, a plurality of lead winding connections, and a plurality of tapped winding connections, wherein the plurality of tapped winding connections include a first tapped winding connection within a first winding of the AC motor, a second tapped winding connection within a second winding of the AC motor, and a third tapped winding connection within a third winding of the AC motor, wherein the first, second, and third windings are in a star or Y-connection configuration; a first contactor coupled in series between the variable frequency drive and the plurality of tapped winding connections, the first contactor controlled by the variable frequency drive to selectively connect and disconnect the output voltage to and from the plurality of tapped winding connections; and a second contactor coupled in series to the plurality of lead winding connections, the second contactor controlled by the variable frequency drive to selectively connect and disconnect power received from the utility power source to and from the plurality of lead winding connections, wherein the output voltage has a maximum peak magnitude in a range of about 33% to about 67% of the rated voltage of the AC motor, wherein while the second contactor has disconnected utility power from the plurality of lead winding connections, the variable frequency drive is configured to cause the first contactor to connect the output voltage of the variable frequency drive to the plurality of tapped winding connections, which causes the AC motor to increase in speed, wherein after the output voltage and frequency of power provided to the AC motor from the variable frequency drive has caused an increase in speed of the AC motor, the variable frequency drive is configured to cause the first contactor to disconnect the output voltage of the variable frequency drive from the plurality of tapped windings and cause the second contactor to connect utility power received from the utility power source to the plurality of lead winding connections.