# US 2023/0054916 A1 · Three-Level Brake Chopper and Method for Controlling Three-Level Brake Chopper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054916 A1 - Document ID: US20230054916A1 - Status: Published application - Kind: A1 - Application number: 17/821,521 - Filed: 2022-08-23 - Published: 2023-02-23 - Earliest claimed: 2021-08-23 - Assignees: ABB Schweiz AG - Applicants: ABB Schweiz AG - Inventors: Tero Viitanen - Web page: https://patentgrep.com/patent/US20230054916A1 ## CPC - H02H 7/122: for inverters, i.e. DC/AC converters - H02P 29/02: Providing protection against overload without automatic interruption of supply (protection against faults of stepper motors H02P8/36) - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 7/537: using semiconductor devices only, e.g. single switched pulse inverters - H02P 29/024: Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load - H02P 29/0241: {the fault being an overvoltage} - H02P 29/027: {the fault being an over-current} - H02P 29/028: the motor continuing operation despite the fault condition, e.g. eliminating, compensating for or remedying the fault - H02P 29/032: Preventing damage to the motor, e.g. setting individual current limits for different drive conditions - H02P 29/04: by means of a separate brake - 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) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - 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 method for controlling a three-level brake chopper and a three-level brake chopper including, a first controllable semiconductor switch connected between a positive direct current pole and a first connection point, a second controllable semiconductor switch connected between the first connection point and a neutral direct current pole, a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point, a fourth controllable semiconductor switch connected between the second connection point and a negative direct current pole, resistance means connected between the first connection point and the second connection point, and control means configured to control the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state in response to detecting a fault in the resistance means. ## Claims ### Claim 1 A method for controlling a three-level brake chopper comprising: a positive direct current pole, a negative direct current pole, and a neutral direct current pole; a first controllable semiconductor switch connected between the positive direct current pole and a first connection point; a second controllable semiconductor switch connected between the first connection point and the neutral direct current pole; a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point; a fourth controllable semiconductor switch connected between the second connection point and the negative direct current pole; and resistance means connected between the first connection point and the second connection point, the method comprising: in response to detecting a fault in the resistance means, controlling the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state. ### Claim 2 (depends on 1) The method of claim 1, further comprising: in response to detecting the fault in the resistance means, controlling the first controllable semiconductor switch and the fourth controllable semiconductor switch into a non-conducting state. ### Claim 3 (depends on 2) The method of claim 2, wherein the controlling of the first controllable semiconductor switch and the fourth controllable semiconductor switch into the non-conducting state is performed before the controlling of the second controllable semiconductor switch and the third controllable semiconductor switch into the conducting state. ### Claim 4 (depends on 1) The method of claim 1, further comprising detecting the fault in the resistance means on the basis of one or more current and/or voltage quantities related to the three-level brake chopper and/or on the basis of one or more signals received. ### Claim 5 A three-level brake chopper comprising: a positive direct current pole, a negative direct current pole, and a neutral direct current pole; a first controllable semiconductor switch connected between the positive direct current pole and a first connection point; a second controllable semiconductor switch connected between the first connection point and the neutral direct current pole; a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point; a fourth controllable semiconductor switch connected between the second connection point and the negative direct current pole; resistance means connected between the first connection point and the second connection point; and a control arrangement configured to control the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state in response to detecting a fault in the resistance means. ### Claim 6 (depends on 5) The three-level brake chopper of claim 5, wherein the control arrangement is configured to control the first controllable semiconductor switch and the fourth controllable semiconductor switch into a non-conducting state in response to detecting the fault in the resistance means. ### Claim 7 (depends on 6) The three-level brake chopper of claim 6, wherein the control arrangement is configured to perform the controlling of the first controllable semiconductor switch and the fourth controllable semiconductor switch into the non-conducting state is performed before the controlling of the second controllable semiconductor switch and the third controllable semiconductor switch into the conducting state. ### Claim 8 (depends on 5) The three-level brake chopper of claim 5, wherein the control arrangement is configured to detect the fault in the resistance means on the basis of one or more current and/or voltage quantities related to the three-level brake chopper and/or on the basis of one or more signals received. ### Claim 9 (depends on 8) The three-level brake chopper of claim 8, wherein the control arrangement is configured to monitor one or more current and/or voltage quantities related to the three-level brake chopper. ### Claim 10 (depends on 5) The three-level brake chopper of claim 5, wherein the resistance means comprise at least one resistor. ### Claim 11 (depends on 10) The three-level brake chopper of claim 10, wherein the resistance means comprise two or more resistors connected in series and/or in parallel with each other. ### Claim 12 (depends on 10) The three-level brake chopper of claim 10, wherein the resistance means comprise two portions connected in series between the first connection point and the second connection point, wherein a connection point between the two portions is connected to the neutral direct current pole. ### Claim 13 (depends on 5) The three-level brake chopper of claim 5, comprising a first diode connected in parallel with the second controllable semiconductor switch and a second diode connected in parallel with the third controllable semiconductor switch. ### Claim 14 (depends on 13) The three-level brake chopper of claim 13, comprising a third diode connected in parallel with the first controllable semiconductor switch and a fourth diode connected in parallel with the fourth controllable semiconductor switch. ### Claim 15 (depends on 5) The three-level brake chopper of claim 5, wherein the controllable semiconductor switches are insulated-gate bipolar transistors or field-effect transistors. ### Claim 16 A three-level converter device, comprising a three-level brake chopper comprising: a positive direct current pole, a negative direct current pole, and a neutral direct current pole; a first controllable semiconductor switch connected between the positive direct current pole and a first connection point; a second controllable semiconductor switch connected between the first connection point and the neutral direct current pole; a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point; a fourth controllable semiconductor switch connected between the second connection point and the negative direct current pole; at least one resistor connected between the first connection point and the second connection point; and a control arrangement configured to control the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state in response to detecting a fault in the at least one resistor. ### Claim 17 A three-level brake chopper apparatus comprising: a positive direct current pole, a negative direct current pole, and a neutral direct current pole; a first controllable semiconductor switch connected between the positive direct current pole and a first connection point; a second controllable semiconductor switch connected between the first connection point and the neutral direct current pole; a third controllable semiconductor switch connected between the neutral direct current pole and a second connection point; a fourth controllable semiconductor switch connected between the second connection point and the negative direct current pole; at least one brake resistor connected between the first connection point and the second connection point; and a control arrangement comprising a processor, and a memory storing instructions that, when executed by the processor, cause the control arrangement to control the second controllable semiconductor switch and the third controllable semiconductor switch into a conducting state in response to detecting a fault in the at least one brake resistor.