# US 2026/0074533 A1 · Apparatus and method for controlling main line switch > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0074533 A1 - Document ID: US20260074533A1 - Status: Published application - Kind: A1 - Application number: 19/289,729 - Filed: 2025-08-04 - Published: 2026-03-12 - Earliest claimed: 2024-09-12 - Assignees: Samsung SDI Co., Ltd. - Applicants: Samsung SDI Co., Ltd. - Inventors: Yoshiaki Okui - Web page: https://patentgrep.com/patent/US20260074533A1 ## CPC - H02H 7/268: {for DC systems} - H02J 7/62: against overcurrent - H02H 3/033: with several disconnections in a preferential order, {e.g. following priority of the users, load repartition}(H02H3/06 takes precedence) - H02H 3/087: for DC applications - H02H 3/093: with timing means {(in general H02H3/027; thermal delay H02H3/085; timing means for undervoltage protection H02H3/247)} - H02H 7/261: {involving signal transmission between at least two stations (transmission of signals in general H02H1/0061)} - H02J 1/10: Parallel operation of DC sources - H02J 7/443: {using passive battery identification means, e.g. resistors or capacitors (identification by mechanical connections H02J7/751)} - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - H02J 7/855: {with circuits adapted for supplying loads from the battery} - H02H 7/18: for batteries; for accumulators - 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 ## Abstract An apparatus for controlling a main line switch mounted on an energy storage system is provided. The energy storage system includes a plurality of battery racks and a disconnect switch unit. The apparatus includes: a battery connection unit respectively on each of the battery racks, the battery connection unit being configured to measure a current of a corresponding one of the battery racks by using a built-in current measurement unit and to generate an overcurrent detection signal when the current of the corresponding one of the battery racks exceeds an overcurrent protection level; and a switch controller configured to open the disconnect switch unit to block a main line current flowing to the energy storage system in response to the overcurrent detection signal from a reference number or more of battery connection units. ## Claims ### Claim 1 An apparatus for controlling a main line switch mounted on an energy storage system, the energy storage system comprising a plurality of battery racks and a disconnect switch unit, the apparatus comprising: a battery connection unit respectively on each of the battery racks, the battery connection unit being configured to measure a current of a corresponding one of the battery racks by using a built-in current measurement unit and to generate an overcurrent detection signal when the current of the corresponding one of the battery racks exceeds an overcurrent protection level; and a switch controller configured to open the disconnect switch unit to block a main line current flowing to the energy storage system in response to the overcurrent detection signal from a reference number or more of battery connection units. ### Claim 2 (depends on 1) The apparatus as claimed in claim 1, wherein, the battery connection unit is configured to open a contactor of the corresponding one of the battery racks after a time delay from a time point when the overcurrent detection signal is generated to block a current flowing to the corresponding one of the battery racks. ### Claim 3 (depends on 1) The apparatus as claimed in claim 1, wherein the current measurement unit comprises a shunt resistor. ### Claim 4 (depends on 1) The apparatus as claimed in claim 1, wherein the battery connection unit transmits the overcurrent detection signal to the switch controller as a contact point signal. ### Claim 5 (depends on 1) The apparatus as claimed in claim 1, wherein the battery connection unit is configured to: measure the current of the corresponding one of the battery racks at sampling periods; and generate the overcurrent detection signal based on the number of times the current of the corresponding one of the battery racks exceeds the overcurrent protection level and transmit the overcurrent detection signal to the switch controller. ### Claim 6 (depends on 1) The apparatus as claimed in claim 1, wherein the battery connection unit is configured to: measure the current of the corresponding one of the battery racks at sampling periods; and generate the overcurrent detection signal when the current of the corresponding one of the battery racks continuously exceeds the overcurrent protection level a set number of times and transmit the overcurrent detection signal to the switch controller. ### Claim 7 (depends on 1) The apparatus as claimed in claim 1, wherein the number of battery connection units is two or more. ### Claim 8 (depends on 1) The apparatus as claimed in claim 1, wherein the battery connection unit is configured to: transmit the overcurrent detection signal to the switch controller as a contact point signal; and after a preset time delay from a time point when the overcurrent detection signal is generated, open a contactor of the corresponding one of the battery racks to block a current flowing thereto, and wherein the time delay is greater than a sum of a time for transmitting the contact point signal to the switch controller from the battery connection unit and an operation time of the disconnect switch unit. ### Claim 9 A method of controlling a main line switch of an energy storage system comprising a plurality of battery racks, the method comprising: measuring, by a battery connection unit respectively on each of the battery racks, a current of a corresponding one of the battery racks by using a current measurement unit, generating an overcurrent detection signal when the current of the corresponding one of the battery racks exceeds an overcurrent protection level, and transmitting the overcurrent detection signal to a switch controller; and opening, by the switch controller, a disconnect switch unit to block a main line current flowing to the energy storage system when receiving a number or more of overcurrent detection signals. ### Claim 10 (depends on 9) The method as claimed in claim 9, further comprising opening, by the battery connection unit, a contactor of the corresponding one of the battery racks to block a current flowing thereto after a preset time delay from a time point when the overcurrent detection signal is generated. ### Claim 11 (depends on 9) The method as claimed in claim 9, wherein the current measurement unit comprises a shunt resistor. ### Claim 12 (depends on 9) The method as claimed in claim 9, wherein the measuring of the current comprises transmitting, by the battery connection unit, the overcurrent detection signal to the switch controller as a contact point signal. ### Claim 13 (depends on 9) The method as claimed in claim 9, wherein the measuring of the current comprises measuring, by the battery connection unit, the current of the corresponding one of the battery racks at sampling periods, generating the overcurrent detection signal based on the number of times the current of the corresponding one of the battery racks exceeds the overcurrent protection level, and transmitting the overcurrent detection signal to the switch controller. ### Claim 14 (depends on 9) The method as claimed in claim 9, wherein the measuring of the current comprises measuring, by the battery connection unit, the current of the corresponding one of the battery racks at sampling periods, generating the overcurrent detection signal when the current of the corresponding one of the battery racks continuously exceeds the overcurrent protection level a set number of times, and transmitting the overcurrent detection signal to the switch controller. ### Claim 15 (depends on 9) The method as claimed in claim 9, wherein the number of overcurrent detection signals is two or more. ### Claim 16 (depends on 9) The method as claimed in claim 9, further comprising opening, by the battery connection unit, a contactor of the corresponding one of the battery racks to block a current flowing to the corresponding one of the battery racks after a time delay from a time point when the overcurrent detection signal is generated, wherein, in the measuring of the current, the battery connection unit transmits the overcurrent detection signal to the switch controller as a contact point signal, and wherein the time delay is greater than a sum of a time for transmitting the contact point signal to the switch controller from the battery connection unit and an operation time of the disconnect switch unit.