US 12,431,792 B2
Synchronous switch-mode active electromagnetic interference cancellation circuit and method
Alex J. Hanson, Austin, TX (US); and Duy T. Nguyen, Austin, TX (US)
Assigned to Board of Regents, The University of Texas System, Austin, TX (US)
Filed by Board of Regents, The University of Texas System, Austin, TX (US)
Filed on Feb. 7, 2023, as Appl. No. 18/165,887.
Claims priority of provisional application 63/307,565, filed on Feb. 7, 2022.
Prior Publication US 2023/0253878 A1, Aug. 10, 2023
Int. Cl. H02M 3/155 (2006.01); H02M 1/44 (2007.01)
CPC H02M 1/44 (2013.01) [H02M 3/155 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a power converter or electric circuit comprising a first set of switching elements and a first inductor or capacitor located at an input to the set of switching elements, wherein an input source voltage is applied to the power converter or electric circuit comprising the first set of switching elements, and the first inductor or capacitor have a voltage rating equal to or greater than the applied input source voltage; and
a switch-mode active electromagnetic interference cancellation circuit comprising a second set of switching elements, said switch-mode active electromagnetic interference cancellation circuit having an output voltage less than the input source voltage, and a second inductor coupled to the first inductor or capacitor through a second capacitor, said second inductor further coupled to an output from the switch-mode active electromagnetic interference cancellation circuit, the second inductor having a voltage rating equal to or greater than the output voltage rating of the switch-mode active electromagnetic interference cancellation circuit and less than the voltage rating of the first capacitor or inductor, wherein the second capacitor isolates and protects the second inductor and the switch-mode active electromagnetic interference cancellation circuit from the input source voltage, and wherein a controller is operatively coupled to the second set of switching elements to control switching operations of the second set of switching elements to apply an opposing alternating voltage or current to the second inductor to cancel high-frequency ripples flowing through the first inductor or capacitor generated from switching of the first set of switching elements.