# US 2023/0055041 A1 · Hybrid core magnetics > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0055041 A1 - Document ID: US20230055041A1 - Status: Published application - Kind: A1 - Application number: 17/758,918 - Filed: 2021-01-15 - Published: 2023-02-23 - Earliest claimed: 2020-01-16 - Assignees: Trustees of Dartmouth College; Massachusetts Institute of Technology - Applicants: Trustees of Dartmouth College; Massachusetts Institute of Technology - Inventors: Charles R. SULLIVAN; David J. PERREAULT - Web page: https://patentgrep.com/patent/US20230055041A1 ## CPC - H01F 27/2895: {Windings disposed upon ring cores} - H01F 3/10: Composite arrangements of magnetic circuits - H01F 3/14: Constrictions; Gaps, e.g. air-gaps (in magnetic shunt paths H01F3/12) - H01F 27/363: {made of electrically conductive material} - H01F 2003/106: {Magnetic circuits using combinations of different magnetic materials} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A magnetic device, including a hybrid core including a first magnetic material as a first flux path that carries a low-frequency flux component and a second magnetic material as a second flux path that carries a high-frequency flux component that is a higher frequency flux component than the low-frequency flux component, in which the hybrid core controls distribution of the low-frequency flux component and substantially separates the low-frequency flux component and the high-frequency component; and at least one set of winding turns. The hybrid core includes at least one air gap to provide control over inductance of the magnetic device. ## Claims ### Claim 1 A magnetic device, comprising: a hybrid core including a first magnetic material as a first flux path that carries a low-frequency flux component and a second magnetic material as a second flux path that carries a high-frequency flux component that is a higher frequency flux component than the low-frequency flux component, wherein the hybrid core controls distribution of the low-frequency flux component and substantially separates the low-frequency flux component and the high-frequency component; and at least one set of winding turns, wherein the hybrid core includes at least one air gap to provide control over inductance of the magnetic device. ### Claim 2 (depends on 1) The magnetic device of claim 1, wherein the hybrid core is in a form of a loop, the first magnetic material is steel and the second magnetic material is ferrite stacked on the first magnetic material, and the at least one set of winding turns is a copper layer on the steel that controls distribution of the frequency components between the first magnetic material and the second magnetic material. ### Claim 3 (depends on 1) The magnetic device of claim 1, wherein the hybrid core is in a form of a loop, the first magnetic material is steel and the second magnetic material is ferrite, the steel portion of the core is substantially surrounded by the ferrite, and a conductivity of the steel provides a shield for the high-frequency flux component. ### Claim 4 (depends on 1) The magnetic device of claim 1, wherein the hybrid core is in a form of a loop, the first magnetic material is steel and the second magnetic material is ferrite, and the steel portion of the hybrid core comprises laminated steel subsections to control eddy currents. ### Claim 5 (depends on 1) The magnetic device of claim 1, wherein the hybrid core is in a form of a loop, the at least one air gap includes a plurality of air gaps, and the plurality air gaps controls permeability in the second magnetic material portion. ### Claim 6 (depends on 1) The magnetic device of claim 1, wherein the hybrid core is in a form of a substantially round enclosure including the first magnetic material in the form of an outer high-permeability steel shell, and the second magnetic material in the form of an inner ferrite pot core with a center post. ### Claim 7 (depends on 6) The magnetic device of claim 6, further comprising: copper shield rings provided to limit penetration of the high-frequency flux component to the outer steel section. ### Claim 8 (depends on 1) The magnetic device of claim 1, wherein the hybrid core includes more than two magnetic materials as respective core flux paths, and the at least one air gap includes a plurality of air gaps. ### Claim 9 (depends on 1) The magnetic device of claim 1, wherein the at least one set of winding turns includes at least one shorted turn. ### Claim 10 (depends on 1) The magnetic device of claim 1, wherein the high-frequency flux component is a frequency that is at least one hundred times higher than the low-frequency flux component. ### Claim 11 (depends on 1) The magnetic device of claim 1, wherein the first magnetic material is laminated steel. ### Claim 12 (depends on 1) The magnetic device of claim 1, wherein a resistance of the at least one set of winding turns is sufficient to keep the high-frequency flux component separate from the low-frequency component such that the high-frequency flux component is kept out of the first flux path, high-frequency flux component losses are minimized, losses resulting from low-frequency excitations are minimized, and blocking of the low-frequency flux component from the first flux path is avoided. ### Claim 13 (depends on 12) The magnetic device of claim 12, wherein the low-frequency flux component is DC flux, the high-frequency flux component is an AC component, and the winding turns are formed with lower resistance than resistance of winding turns necessary to shield a frequency of the AC component. ### Claim 14 (depends on 1) The magnetic device of claim 1, further comprising: a capacitor connected to the at least one set of winding turns. ### Claim 15 (depends on 6) The magnetic device of claim 6, further comprising: high frequency Litz windings, wherein the at least one set of windings are low-frequency solid windings, and the Litz windings are arranged in parallel with the low-frequency solid windings such that the Litz windings handle the high-frequency component, while low-frequency currents are carried in the solid windings. ### Claim 16 (depends on 15) The magnetic device of claim 15, wherein a higher-order LC network is used for the transition between the high and low impedance. ### Claim 17 (depends on 1) The magnetic device of claim 1, wherein the hybrid core includes more than two magnetic material layers as respective core flux paths, an innermost magnetic material layer has a highest flux density and a lowest frequency component, and an outer magnetic material layer has the lowest flux density and a highest frequency component, and the magnetic material layers are separated by conductive shields to control flux separation among the layers. ### Claim 18 (depends on 1) The magnetic device of claim 1, wherein the at least one air gap includes a first air gap in the first magnetic material of the hybrid core and a second air gap in the second magnetic material of the hybrid core, the first air gap being different from the second aid gap. ### Claim 19 (depends on 18) The magnetic device of claim 18, wherein the first air gap in the first magnetic material is smaller than the second air gap in the second magnetic material. ### Claim 20 (depends on 18) The magnetic device of claim 18, wherein the first air gap in the first magnetic material of the hybrid core is arranged at a different position than the second air gap in the second magnetic material of the hybrid core.