# US 12,015,334 B2 · Power electronic device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,334 B2 - Document ID: US12015334B2 - Status: Granted - Kind: B2 - Application number: 16/695,567 - Filed: 2019-11-26 - Published: 2020-05-28 - Granted: 2024-06-18 - Earliest claimed: 2018-11-27 - Assignees: Danfoss Power Electronics A/S - Applicants: Danfoss Power Electronics A/S - Inventors: Ansgar Nielsen; Henrik Rosendal Andersen; Steen Hornsleth - Web page: https://patentgrep.com/patent/US12015334B2 ## CPC - H02M 1/32: Means for protecting converters other than automatic disconnection - H02M 5/458: using semiconductor devices only - H02M 5/4585: {having a rectifier with controlled elements} - H02M 1/0009: {Devices or circuits for detecting current in a converter} - H02M 1/327: {against abnormal temperatures} - 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 power electronic device includes an input which is connected to an over-current-protection device arrangement and a DC-link, wherein the DC-link includes a series connection of at least two DC-link capacitors. In such a power electronic device the risk of a fire hazard should be minimized. To this end fault detecting element(s) are provided detecting an imbalance between the DC-link capacitors or an overload of at least one of the DC-link capacitors, wherein the fault detecting element(s) control maximum current inducing element(s) connected to the DC-link. ## Claims ### Claim 1 A power electronic device comprising an input which is connected to an over-current-protection device arrangement and a DC-link, wherein the DC-link comprises a series connection of at least two DC-link capacitors, wherein fault detecting means are provided detecting an imbalance between the DC-link capacitors or an overload of at least one of the DC-link capacitors, wherein the fault detecting means control maximum current inducing means connected to the DC-link, wherein the over-current-protection device is configured to become activated after the fault detecting means controls the maximum current inducing means to induce a sufficient current flow in the power electronic device, wherein the over-current-protection device interrupts power flowing through the input when the over-current-protection device is activated, and wherein the input is configured such that during operation of the power electronic device, power flows through the input, when not interrupted, before flowing into the DC-link. ### Claim 2 (depends on 1) The power electronic device according to claim 1, wherein the fault detecting means detect at least one parameter of at least one of the DC-link capacitors. ### Claim 3 (depends on 2) The power electronic device according to claim 2, wherein the fault detecting means compare at least a parameter of one of the capacitors with a parameter of another one of the capacitors. ### Claim 4 (depends on 3) The power electronic device according to claim 3, wherein the parameter is a current through the capacitor or a temperature of the capacitor. ### Claim 5 (depends on 4) The power electronic device according to claim 4, wherein an inverter is connected to the DC-link and the inverter at least partly form the maximum current inducing means. ### Claim 6 (depends on 3) The power electronic device according to claim 3, wherein an inverter is connected to the DC-link and the inverter at least partly form the maximum current inducing means. ### Claim 7 (depends on 3) The power electronic device according to claim 3, wherein the parameter is a temperature of the capacitor. ### Claim 8 (depends on 3) The power electronic device according to claim 3, wherein the parameter is a voltage over the capacitor. ### Claim 9 (depends on 3) The power electronic device according to claim 3, wherein the maximum current inducing means together with or without existing load establishes the sufficient current flow to activate the overcurrent protection arrangement. ### Claim 10 (depends on 2) The power electronic device according to claim 2, wherein an inverter is connected to the DC-link and the inverter at least partly form the maximum current inducing means. ### Claim 11 (depends on 2) The power electronic device according to claim 2, wherein the maximum current inducing means together with or without existing load establishes the sufficient current flow to activate the overcurrent protection arrangement. ### Claim 12 (depends on 1) The power electronic device according to claim 1, wherein an inverter is connected to the DC-link and the inverter at least partly form the maximum current inducing means. ### Claim 13 (depends on 12) The power electronic device according to claim 12, wherein the fault detecting means control the inverter to feed excessive energy to inverter load. ### Claim 14 (depends on 12) The power electronic device according to claim 12, wherein the maximum current inducing means together with or without existing load establishes the sufficient current flow to activate the overcurrent protection arrangement. ### Claim 15 (depends on 1) The power electronic device according to claim 1, wherein the maximum current inducing means together with or without existing load establishes the sufficient current flow to activate the overcurrent protection arrangement. ### Claim 16 (depends on 15) The power electronic device according to claim 15, wherein the maximum current inducing means establish a low impedance connection. ### Claim 17 (depends on 16) The power electronic device according to claim 16, wherein the low impedance connection is a short circuit, downstream the passive rectifier. ### Claim 18 (depends on 1) The power electronic device according to claim 1, wherein in that the maximum current inducing means are mechanically encapsulated. ### Claim 19 (depends on 1) The power electronic device according to claim 1, wherein the over-current-protection device arrangement comprises a fuse, an electronic device, a circuit relay, or an intended weak spot. ### Claim 20 (depends on 1) The power electronic device according to claim 1, wherein the over-current-protection device arrangement comprises an electronic device.