# US 2026/0074512 A1 · Current-Limiting Solid State Circuit Breaker Arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0074512 A1 - Document ID: US20260074512A1 - Status: Published application - Kind: A1 - Application number: 19/320,109 - Filed: 2025-09-05 - Published: 2026-03-12 - Earliest claimed: 2024-09-06 - Assignees: ABB Schweiz AG - Applicants: ABB Schweiz AG - Inventors: Mario Schweizer; Vladan Lazarevic; Markus Andreas Abplanalp - Web page: https://patentgrep.com/patent/US20260074512A1 ## CPC - H02H 9/02: responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} - H02H 9/025: {Current limitation using field effect transistors} - H02H 7/268: {for DC systems} - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract An apparatus includes a main switch, arranged in series between an apparatus-input and an apparatus-output, a first parallel-diode in backward direction and a second parallel-diode in forward direction, the first and second parallel-diodes arranged in series and in parallel to the main switch with a first central node between them; a first branch diode in forward direction and a second branch diode in backward direction, the first and second branch diodes arranged in series between the apparatus-input and the apparatus-output; a chopper-circuit arranged between the first and second central nodes, the chopper-circuit comprising a chopper capacitor arranged between the first and second central nodes and a chopper semiconductor arranged in series with a chopper resistor between the first and second so that the sub-circuit comprising the branch diodes and the chopper-circuit limits the current in case of a short circuit by leading the current through this sub-circuit. ## Claims ### Claim 1 An apparatus for limiting a current in case of a short circuit, the apparatus comprising: a main switch, arranged in series between an apparatus-input and an apparatus-output; a first parallel-diode in backward direction and a second parallel-diode in forward direction, the first parallel-diode and the second parallel-diode arranged in series and in parallel to the main switch, with a first central node between them; a first branch diode in forward direction and a second branch diode in backward direction, the first branch diode and the second branch diode arranged in series between the apparatus-input and the apparatus-output, with a second central node between them; and a chopper-circuit, arranged between the first central node and the second central node, the chopper-circuit comprising: a chopper capacitor, arranged between the first central node and the second central node, and a chopper semiconductor, arranged in series with a chopper resistor, this series arranged between the first central node and the second central node, so that the sub-circuit comprising the branch diodes and the chopper-circuit is configured for limiting the current in case of a short circuit by leading the current through this sub-circuit. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the main switch comprises a first semiconductor and a second semiconductor, the first semiconductor arranged in parallel to the first parallel-diode and the second semiconductor arranged in parallel to the second parallel-diode, the first semiconductor arranged in forward direction and the second semiconductor arranged in backward direction. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the first semiconductor and the second semiconductor are bipolar semiconductors or IGBTs, the first semiconductor and the second semiconductor being arranged in a common emitter arrangement or in a common collector arrangement. ### Claim 4 (depends on 2) The apparatus of claim 2, wherein the first semiconductor and the second semiconductor are MOSFET or JFET semiconductors, the first semiconductor and the second semiconductor being arranged in a common drain arrangement or in a common source arrangement. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the main switch comprises a first reverse blocking IGCT and a second reverse blocking IGCT, arranged antiparallel to each other between the apparatus-input and the apparatus-output. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the main switch comprises a mechanical switch, arranged between an apparatus-input and an apparatus-output. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising a chopper diode in backward direction, the chopper diode being arranged in parallel to the chopper resistor. ### Claim 8 (depends on 1) The apparatus of claim 1, further comprising an inductor, the inductor being arranged between the apparatus-output and a load. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the inductor has an inductance between 1 μH and 500 μH. ### Claim 10 (depends on 1) The apparatus of claim 1, further comprising a mechanical switch, the mechanical switch being arranged between the apparatus-output and the load. ### Claim 11 A method for limiting a current in case of a short circuit using an apparatus 1, the method comprising: providing a main switch, arranged in series between an apparatus-input and an apparatus-output; providing a first parallel-diode in backward direction and a second parallel-diode in forward direction, the first parallel-diode and the second parallel-diode arranged in series and in parallel to the main switch, with a first central node between them; providing a first branch diode in forward direction and a second branch diode in backward direction, the first branch diode and the second branch diode arranged in series between the apparatus-input and the apparatus-output, with a second central node between them; and providing a chopper-circuit, arranged between the first central node and the second central node, the chopper-circuit comprising: a chopper capacitor, arranged between the first central node and the second central node, and a chopper semiconductor, arranged in series with a chopper resistor, this series arranged between the first central node and the second central node, so that the sub-circuit comprising the branch diodes and the chopper-circuit is configured for limiting the current in case of a short circuit by leading the current through this sub-circuit; setting the apparatus in a normal operation mode, in which the main switch is closed; when an overcurrent occurs, setting the apparatus in a current limiting mode, in which the main switch is opened, and a sub-circuit comprising branch diodes and a chopper-circuit mitigates the current in case of a short circuit by leading the current through this sub-circuit, the current limiting mode being performed for a predefined period; and after the predefined period, setting the apparatus in a fast interruption mode, in which the main switches are open and the chopper-circuit is turned off by turning off the chopper semiconductor Sb. ### Claim 12 (depends on 11) The method of claim 11, wherein the duration of the predefined period is between 0.1 ms and 10 ms, and/or wherein the frequency of the chopper-circuit's oscillating mode is between 1 kHz and 20 kHz.