US 12,424,928 B2
Resistor-less pre-charging techniques
Basheer Qattum, Peoria, IL (US); and Dachuan Yu, Dunlap, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on Apr. 13, 2023, as Appl. No. 18/134,099.
Prior Publication US 2024/0348154 A1, Oct. 17, 2024
Int. Cl. H02M 1/36 (2007.01); H02M 1/32 (2007.01)
CPC H02M 1/32 (2013.01) [H02M 1/36 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A power conversion circuit configured to limit inrush current during startup without using resistors, the power conversion circuit comprising:
a first terminal configured to couple to an energy storage device;
a converter circuit coupled to the first terminal, the converter circuit including an electronic switch and a protection diode coupled across the electronic switch;
a switch circuit configured to couple to an AC voltage;
a second terminal coupled to the switch circuit;
a filter circuit coupled between the converter circuit and the second terminal and configured to filter the AC voltage, the filter circuit including:
a first inductor coupled to the converter circuit; and
a capacitor coupled between the first inductor and the second terminal; and
a protection inductor coupled to the first terminal or the second terminal, wherein the protection inductor does not include a transformer, wherein the protection inductor is configured to limit inrush current during startup without using resistors, and wherein the protection inductor is configured to saturate at a current less than a current rating of the protection diode.