# US 12,113,449 B2 · Transformer arrangement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,449 B2 - Document ID: US12113449B2 - Status: Granted - Kind: B2 - Application number: 18/553,045 - Filed: 2022-03-30 - Published: 2024-06-20 - Granted: 2024-10-08 - Earliest claimed: 2021-03-31 - Assignees: Hitachi Energy Ltd - Applicants: Hitachi Energy Ltd - Inventors: Panagiotis Bakas; Roberto Alves; Jan Svensson - Web page: https://patentgrep.com/patent/US12113449B2 ## CPC - H02M 5/22: using discharge tubes with control electrode or semiconductor devices with control electrode - H02M 5/257: using semiconductor devices only - H02M 1/348: {Passive dissipative snubbers} - H02M 5/293: using semiconductor devices only - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) ## Abstract A transformer arrangement comprising a transformer having a primary side for receiving input voltage and current from a source and a secondary side for providing output voltage and current to a load. The transformer arrangement further comprises an AC-AC PE converter connected to a thyristor used for bypassing the AC-AC PE converter in case of a short-circuit fault in a terminal of the primary side and/or the secondary side. The transformer arrangement further comprises a thyristor-based AC-AC PE converter connected to a thyristor-tapped winding. The AC-AC PE converter is connected with the thyristor-tapped winding via the thyristor-based AC-AC PE converter. The thyristor-based AC-AC PE converter is connected to an impedance to protect the thyristor-tapped winding from short-circuit faults of the thyristor-based AC-AC PE converter. ## Claims ### Claim 1 A transformer arrangement comprising: a transformer having a primary side for receiving input voltage and current from a source and a secondary side for providing output voltage and current to a load; an AC-AC Power Electronic (PE) converter connected to a thyristor used for bypassing the AC-AC PE converter in case of a short-circuit fault in a terminal of the primary side and/or the secondary side; wherein the transformer arrangement further comprises a thyristor-based AC-AC PE converter connected to a thyristor-tapped winding and wherein the AC-AC PE converter is connected with the thyristor-tapped winding via the thyristor-based AC-AC PE converter, and wherein the thyristor-based AC-AC PE converter is connected to an impedance to protect the thyristor-tapped winding from short-circuit faults of the thyristor-based AC-AC PE converter, wherein the thyristor-based AC-AC PE converter comprises one or more parallel connected and/or series connected thyristors, and wherein the impedance is a coupled impedance, wherein the coupled impedance is associated to high impedance when a magnetic flux is added when current flows from a top to a bottom terminal of the thyristor-tapped winding and vice versa, and associated to low impedance when the magnetic flux of coupled windings is subtracted when current flows from the top and the bottom terminal of the thyristor-tapped winding to a common terminal of the thyristors and vice versa. ### Claim 2 (depends on 1) The transformer arrangement according to claim 1, wherein the AC-AC PE converter is connected in series with the thyristor-tapped winding. ### Claim 3 (depends on 1) The transformer arrangement according to claim 1, wherein the AC-AC PE converter is connected to an auxiliary winding. ### Claim 4 (depends on 3) The transformer arrangement according to claim 3, wherein the AC-AC PE converter is connected to an impedance to protect the auxiliary winding from a short-circuit fault of the AC-AC PE converter. ### Claim 5 (depends on 3) The transformer arrangement according to claim 3, wherein the auxiliary winding is tapped. ### Claim 6 (depends on 3) The transformer arrangement according to claim 3, wherein the auxiliary winding is separate. ### Claim 7 (depends on 3) The transformer arrangement according to claim 3, wherein the transformer arrangement further comprises a transformer tank, and wherein the AC-AC PE converter, the thyristor-based AC-AC PE converter, and the impedances are installed inside the transformer tank. ### Claim 8 (depends on 3) The transformer arrangement according to claim 3, wherein the transformer arrangement further comprises a transformer tank and a separate container, wherein the impedances are installed inside the transformer tank and wherein the AC-AC PE converter and the thyristor-based AC-AC PE converter are installed in the separate container. ### Claim 9 (depends on 3) The transformer arrangement according to claim 3, wherein the transformer arrangement further comprises a separate container, wherein the impedances, the AC-AC PE converter, and the thyristor-based AC-AC PE converter are installed in the separate container. ### Claim 10 (depends on 1) The transformer arrangement according to claim 1, wherein the impedance is split in two parts, each of which is connected to top and bottom terminals of the thyristor-tapped winding. ### Claim 11 (depends on 1) The transformer arrangement according to claim 1, wherein an RC snubber network is connected in parallel to each thyristor, wherein the RC snubber network comprises a resistor and a capacitor connected in series and/or in parallel. ### Claim 12 (depends on 11) The transformer arrangement according to claim 11, wherein a further RC snubber network is a common snubber network for all thyristors which is connected in parallel to the thyristors, wherein the RC snubber network comprises a resistor and a capacitor connected in series and/or in parallel, or a capacitor.