# US 10,320,308 B2 · Commutating circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,308 B2 - Document ID: US10320308B2 - Status: Granted - Kind: B2 - Application number: 15/301,804 - Filed: 2014-04-04 - Published: 2017-05-04 - Granted: 2019-06-11 - Earliest claimed: 2014-04-04 - Assignees: Siemens Aktiengesellschaft - Applicants: Siemens Aktiengesellschaft - Inventors: Joerg Dorn; Dominik Ergin; Peter Menke; Bernd Utz; Michael Weinhold - Web page: https://patentgrep.com/patent/US10320308B2 ## CPC - H02M 7/10: arranged for operation in series, e.g. for multiplication of voltage - H01H 33/16: Impedances connected with contacts - H01H 33/596: {for interrupting DC} - H01H 33/66: Vacuum switches - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 7/06: using discharge tubes without control electrode or semiconductor devices without control electrode - H02M 1/0074: {Plural converter units whose inputs are connected in series} - H02M 1/325: {with means for allowing continuous operation despite a fault, i.e. fault tolerant converters} - H02M 1/34: Snubber circuits - Y02E 10/76: Power conversion electric or electronic aspects - Y02E 60/60: Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD] - 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) - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A commutating circuit for an electronic power converter has a first switching device, by which the electronic power converter can be electrically bridged, and a circuit part for limiting the size of the time-related voltage change of a voltage present on the first switching device. The circuit part limits the time-related voltage variation. ## Claims ### Claim 1 A commutating circuit for a power converter, the commutating circuit comprising: a first switching device having a first terminal and a second terminal; a second switching device; and a circuit part for limiting a size of a time-related variation of a voltage which occurs across said first switching device, said circuit part having an energy store connected in parallel with said first switching device, said energy store having a first terminal connected directly to said first terminal of said first switching device and a second terminal connected directly to said second terminal of said first switching device; said first switching device and said circuit part together forming a parallel electric circuit; said second switching device being electrically connected in series with said parallel electric circuit to form an electrical series circuit disposed to bridge the power converter. ### Claim 2 (depends on 1) The commutating circuit according to claim 1, wherein said circuit part has a surge voltage protector for protecting said energy store against a voltage surge. ### Claim 3 (depends on 1) The commutating circuit according to claim 1, wherein the power converter is a rectifier. ### Claim 4 (depends on 1) The commutating circuit according to claim 1, wherein said first switching device is connected to a first DC voltage connection and, via said second switching device, to a second DC voltage connection on the power converter. ### Claim 5 (depends on 1) The commutating circuit according to claim 1, wherein at least one of said first switching device or said second switching device has a mechanical switch. ### Claim 6 (depends on 1) The commutating circuit according to claim 1, wherein said second switching device is a series circuit containing a plurality of mechanical switches. ### Claim 7 (depends on 1) The commutating circuit according to claim 1, wherein said first switching device is connected to a first DC voltage connection on the power converter and said second switching device is connected to a second DC voltage connection on the power converter. ### Claim 8 (depends on 1) The commutating circuit according to claim 1, wherein said energy store is a capacitor. ### Claim 9 (depends on 5) The commutating circuit according to claim 5, wherein said mechanical switch is a vacuum switch. ### Claim 10 A power converter, comprising: a commutating circuit containing a switching device and a circuit part for limiting a size of a time-related variation of a voltage which occurs across said switching device, said circuit part having an energy store connected in parallel with said switching device, said energy store having a first terminal connected directly to a first terminal of said switching device and a second terminal connected directly to a second terminal of said switching device; said first switching device and said circuit part forming a parallel electric circuit; and a second switching device electrically connected in series with said parallel electric circuit to form an electrical series circuit disposed to bridge the power converter. ### Claim 11 An arrangement, comprising: a plurality of power converters electrically connected in series, each of said power converters containing a commutating circuit having a switching device by which a respective one of said power converters is electrically bridged and a circuit part for limiting a size of a time-related variation of a voltage which occurs across said switching device, each said circuit part having an energy store connected in parallel with said switching device, said energy store having a first terminal connected directly to a first terminal of said switching device and a second terminal connected directly to a second terminal of said switching device said first switching device and said circuit part forming a parallel electric circuit; and a second switching device electrically connected in series with said parallel electric circuit to form an electrical series circuit disposed to bridge the power converter. ### Claim 12 A method for commutation of an electric current by a first switching device of a commutating circuit in a power converter, the power converter being bridgeable by means of the first switching device and a second switching device connected in series with the first switching device, which comprises the steps of: flowing the electric current initially through a closed first switching device and a closed second switching device connected in series with the first switching device; opening the first switching device; and providing a circuit part with an energy store connected in parallel with said first switching device, the circuit part being a part of the commutating circuit and the energy store having a first terminal connected directly to a first terminal of the first switching device and a second terminal connected directly to a second terminal of the first switching device; commutating the electric current by the first switching device to the circuit part of the commutating circuit, using the circuit part to limit a size of a time-related variation of a voltage which occurs across the first switching device upon the opening of the first switching device, and as a result of a limitation of the time-related variation of the voltage, achieving a current zero-crossing in the first switching device; and charging the energy store with the current commutated to the circuit part and, as a result of a time-related increase in the voltage on the energy store, commutating the electric current from the circuit part to the power converter; and after commutation of the electric current to the power converter, opening the second switching device. ### Claim 13 (depends on 12) The method according to claim 12, wherein the energy store includes a capacitor and, as a result of the time-related increase in a capacitor voltage of the capacitor, the electric current is commutated from the circuit part to the power converter. ### Claim 14 (depends on 13) The method according to claim 13, which further comprises limiting a magnitude of the capacitor voltage to a maximum voltage value.