US 12,071,313 B2
Variable DC bus voltage in an independent cart system
Nandini Ganesan, Milwaukee, WI (US); Patrick E. Ozimek, Milwaukee, WI (US); and Omid Shirazi, Brown Deer, WI (US)
Assigned to Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed by Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US)
Filed on Dec. 24, 2020, as Appl. No. 17/133,844.
Prior Publication US 2022/0204284 A1, Jun. 30, 2022
Int. Cl. B60L 13/03 (2006.01); B60L 9/18 (2006.01); B65G 47/64 (2006.01)
CPC B65G 47/642 (2013.01) 13 Claims
OG exemplary drawing
 
1. An independent cart system, comprising:
a track including a plurality of track segments, where each of the plurality of track segments comprises:
a plurality of drive coils, wherein each of the plurality of drive coils is configured to generate an electromagnetic field responsive to an AC voltage applied to the drive coil, and
at least one power segment, wherein each power segment is configured to receive a DC voltage as an input and to convert the DC voltage to the AC voltage applied to each of the plurality of drive coils;
a first DC bus connected to a first portion of the plurality of track segments;
a second DC bus connected to a second portion of the plurality of track segments;
a first power supply operative to supply the DC voltage to the first DC bus at a first amplitude;
a second power supply operative to supply the DC voltage to the second DC bus at a second amplitude; and
at least one mover configured to travel along the track, wherein the at least one mover includes a drive member configured to interact with the electromagnetic fields generated by each of the plurality of drive coils to propel the at least one mover along the track, wherein:
the first amplitude of the DC voltage is less than the second amplitude of the DC voltage,
the at least one power segment for each track segment in the first portion of the plurality of track segments is configured to supply current to each of the plurality of drive coils up to a first maximum current, and
the first maximum current is greater than a second maximum current for the at least one power segment for each track segment in the second portion of the plurality of track segments.