US 9,812,967 B2
Inrush current limiting method based on buck+boost topology
Maximiliano O. Sonnaillon, Santa Fe (AR)
Assigned to Pacific Power Source, Inc., Irvine, CA (US)
Filed by Pacific Power Source, Inc., Irvine, CA (US)
Filed on May 19, 2016, as Appl. No. 14/999,524.
Claims priority of provisional application 62/179,905, filed on May 21, 2015.
Prior Publication US 2016/0344292 A1, Nov. 24, 2016
Int. Cl. H02M 3/158 (2006.01); H02M 1/32 (2007.01); H02M 1/36 (2007.01); H02M 1/00 (2006.01)
CPC H02M 3/1582 (2013.01) [H02M 1/32 (2013.01); H02M 1/36 (2013.01); H02M 2001/0009 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A cascaded buck+boost inrush limiter where the buck converter is only allowed to switch for very short times and stays turned on, or off, during steady state operation comprising:
an input bridge;
a buck converter comprising a buck switch and diode, and the buck converter connected to the input bridge;
a boost converter comprising a boost switch and diode, and the boost converter connected to the buck converter;
common passive components shared by the buck converter and the boost converter, the common passive components comprising a inductor and a capacitor;
a control system connected to the buck and boost converters to control the buck and boost converters, the control system comprising:
i) a digital controller for receiving inductor current measurements for a duty cycle command from a single loop current feedback during operation, the control system operable such that when the duty cycle command equals zero, then the converters are off and when the duty cycle command is higher than zero but less than one the boost converter stays off but the buck converter goes from 0 to 100% duty, and when the duty cycle command is between one and two the buck stays at 100% and the boost goes from 0 to 100% duty, and if the maximum buck switching time is exceeded, then the control system shuts down the converters;
ii) an analog comparator for peak current detection and during operation if a peak current is detected the buck and boost converters switches are turned off until the next pulse-width modulated period.