# US 12,007,452 B2 · Locating a ground fault in a DC system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,452 B2 - Document ID: US12007452B2 - Status: Granted - Kind: B2 - Application number: 17/439,110 - Filed: 2020-03-06 - Published: 2022-05-12 - Granted: 2024-06-11 - Earliest claimed: 2019-03-18 - Assignees: Siemens Aktiengesellschaft - Applicants: Siemens Aktiengesellschaft - Inventors: Hubert Schierling; Benno Weis - Web page: https://patentgrep.com/patent/US12007452B2 ## CPC - G01R 31/086: {in power transmission or distribution networks, i.e. with interconnected conductors} - G01R 31/52: Testing for short-circuits, leakage current or ground faults - H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)} - H02H 3/042: {combined with means for locating the fault (locating faults in cables G01R31/08)} - H02H 3/16: responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) - H02H 7/262: {involving transmissions of switching or blocking orders} - H02H 7/268: {for DC systems} - H02J 13/13: characterised by the transmission of data to equipment in the power network - H02J 1/06: Two-wire DC power distribution systems - Y02E 60/00: Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation - Y04S 10/52: Outage or fault management, e.g. fault detection or location - Y04S 40/12: characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y04S: SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS ## Abstract A method is for locating a ground fault in a DC system to which a plurality of load zones can be connected. The method includes specifying a time window and, after the ground fault is detected, assigning the ground fault to a load zone which was connected to the DC system within the time window before the detection of the ground fault. ## Claims ### Claim 1 A method for locating a ground fault in a DC system to which a plurality of load zones are connectable, the method comprising: defining a time window; and assigning, after detection of the ground fault, the ground fault to a load zone connected to the DC system, within the time window defined before detection of the ground fault, wherein upon the plurality of load zones being connected to the DC system within the time window defined before the detection of the ground fault, the ground fault is assigned to one of the plurality of load zones connected to the DC system relatively latest within the time window. ### Claim 2 (depends on 1) The method of claim 1, further comprising: disconnecting, from the DC system, the load zone of the plurality of load zones to which the ground fault is assigned. ### Claim 3 (depends on 2) The method of claim 2, further comprising: checking, after disconnection of the load zone from the DC system, to ascertain whether the ground fault is still present, and upon the checking indicating that the ground fault is still present in the DC system after disconnection of the load zone from the DC system, canceling the assigning of the ground fault to the load zone and reconnecting the load zone to the DC system. ### Claim 4 (depends on 1) The method of claim 1, further comprising: storing, by an evaluation unit, a detection time of the detection of the ground fault, the time window and, for each instance of connecting a load zone, a connecting time of the connecting and a connecting assignment of the connecting time to the load zone connected, and wherein the ground fault is assigned to the load zone based upon stored data. ### Claim 5 (depends on 4) The method of claim 4, wherein the evaluation unit is a control unit configured to control the connecting of the load zone. ### Claim 6 (depends on 4) The method of claim 4, wherein the evaluation unit is a ground fault monitoring unit configured to detect the ground fault. ### Claim 7 (depends on 4) The method of claim 4, further comprising: reporting, by a control unit, the connecting time and the corresponding connecting assignment to the evaluation unit to control the connecting of the load zone. ### Claim 8 (depends on 4) The method of claim 4, wherein the ground fault is detected by a ground fault monitoring unit and reported to the evaluation unit. ### Claim 9 (depends on 1) The method of claim 1, wherein the DC system has, for each of the plurality of load zones, a respective connecting unit assigned to a respective load zone of the plurality of load zones, the respective load zone being connectable to the DC system by the respective connecting unit, and each respective connecting unit being configured to store the time window and determine, for each instance of connecting the respective load zone, whether the connecting was effected within the time window before the detection of the ground fault. ### Claim 10 (depends on 9) The method of claim 9, wherein the ground fault is detected by a ground fault monitoring unit and reported to each respective connecting unit. ### Claim 11 (depends on 9) The method of claim 9, wherein each respective connecting unit is configured to detect the ground fault. ### Claim 12 (depends on 1) The method of claim 1, wherein, after the ground fault has been detected, the ground fault cannot be assigned to a load zone of the plurality of load zones because no load zone was connected to the DC system within the time window before the detection of the ground fault, wherein a faulty load zone is determined by a procedure in which firstly all the plurality of load zones are disconnected from the DC system and then each respective load zones of the plurality of load zones are connected to the DC system at mutually different connecting times for a connected duration that is relatively longer than the time window and does not overlap the connected duration of another load zone of the plurality of load zones, and for each instance of connecting a respective load zone, a check is made to ascertain whether the ground fault occurs within the time window after the connecting. ### Claim 13 A DC system comprising: an evaluation unit, the evaluation unit configured to store data of a detection time for detection of a ground fault, define a time window and, for each respective instance of connecting a load zone of a plurality of load zones, a respective connecting time of the connecting the load zone and a respective connecting assignment of the respective connecting time to the load zone connected, and assign, after detection of the ground fault, the ground fault to the respective load zone based upon the stored data. ### Claim 14 (depends on 13) The DC system of claim 13, wherein the plurality of load zones are connectable via respective connecting units; the DC system further includes a ground fault monitoring unit; and the ground fault monitoring unit is configured to report a detected ground fault to the evaluation unit. ### Claim 15 A DC system, comprising: main electrical lines; a ground fault monitoring unit connected to the main electrical lines; a plurality of connectable load zones; and for each respective load zone of the plurality of connectable load zones, a respective connecting unit assigned to each respective connectable load zone, each respective connectable load zone being connectable to the DC system by each respective connecting unit and each respective connecting unit being configured to store a definable time window, and determine, for each instance of connecting the respective connectable load zone, whether the connecting was affected within the definable time window before reporting of a ground fault by the ground fault monitoring unit. ### Claim 16 A method for locating a ground fault in a DC system to which a plurality of load zones are connectable, the method comprising: defining a time window; and assigning, after detection of the ground fault, the ground fault to a load zone connected to the DC system, within the time window defined before detection of the ground fault; and storing, by an evaluation unit, a detection time of the detection of the ground fault, the time window and, for each instance of connecting a load zone, a connecting time of the connecting and a connecting assignment of the connecting time to the load zone connected, wherein the ground fault is assigned to the load zone based upon stored data. ### Claim 17 (depends on 16) The method of claim 16, wherein the evaluation unit is a control unit configured to control the connecting of the load zone. ### Claim 18 (depends on 16) The method of claim 16, wherein the evaluation unit is a ground fault monitoring unit configured to detect the ground fault. ### Claim 19 (depends on 16) The method of claim 16, further comprising: reporting, by a control unit, the connecting time and the corresponding connecting assignment to the evaluation unit to control the connecting of the load zone. ### Claim 20 (depends on 16) The method of claim 16, wherein the ground fault is detected by a ground fault monitoring unit and reported to the evaluation unit.