# US 12,191,672 B2 · Devices and methods for disconnecting a grid power source from an electrical distribution system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,672 B2 - Document ID: US12191672B2 - Status: Granted - Kind: B2 - Application number: 18/206,227 - Filed: 2023-06-06 - Published: 2023-12-14 - Granted: 2025-01-07 - Earliest claimed: 2022-06-10 - Assignees: Schneider Electric Industries SAS - Applicants: Schneider Electric Industries SAS - Inventors: Swardheep Babu; Zaixing Wang; Benoît Grappe; Samuel Kamajaya; Jikang Xu - Web page: https://patentgrep.com/patent/US12191672B2 ## CPC - H02J 3/388: Arrangements for the handling of islanding, e.g. for disconnection or for avoiding the disconnection of power - H02J 9/062: {for AC powered loads} - H02J 3/0012: characterised by the contingency detection means in AC networks, e.g. using phasor measurement units [PMU], synchrophasors or contingency analysis - H02J 3/32: using batteries or super capacitors with converting means - G01R 31/086: {in power transmission or distribution networks, i.e. with interconnected conductors} - H02J 2103/35: Grid-level management of power transmission or distribution systems, e.g. load flow analysis or active network management - Y02E 40/10: Flexible AC transmission systems [FACTS] - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract An electrical distribution system is configured to supply electric power to an electric load and includes a feeder, a battery energy storage system, an electrical switchgear device and an electronic controller. The switchgear device is configured to selectively connect the connection point to the feeder, wherein the electronic controller is configured to: detect an electric fault representative of a power loss event on the grid power source; upon detecting an electric fault, automatically open the electrical switchgear device to disconnect the grid power source from the feeder; and ensure that the battery system supplies electric power to the electric load while operating in a virtual-synchronous generator control mode. ## Claims ### Claim 1 An electrical distribution system configured to supply electric power to an electric load, the electrical distribution system comprising a feeder for connecting at least one electric load, a battery energy storage system connected to the feeder, and a connection point for connecting a grid power source to the feeder, the battery energy storage system comprising a battery, an electrical switchgear device and an electronic controller, the electrical switchgear device being configured to selectively connect the connection point to the feeder, wherein the electronic controller is configured to implement a virtual-synchronous generator control mode, and wherein the electronic controller is configured to: detect an electric fault representative of a power loss event on the grid power source, upon detecting an electric fault, automatically open the electrical switchgear device to disconnect the grid power source from the feeder, and ensure that the battery energy storage system supplies electric power to the electric load while operating in a virtual-synchronous generator control mode, wherein detecting an electric fault comprises detecting a voltage vector shift in voltage delivered by the grid power source, and wherein detecting the voltage vector shift in the voltage delivered by the grid power source comprises: measuring a duration of each cycle of the voltage delivered by the grid power source for each electrical phase, comparing a duration of a current voltage cycle with a duration of a previous voltage cycle, identifying a change in a voltage vector angle, and identifying that a power loss condition has occurred if the change of the voltage vector angle exceeds a predefined threshold angle value. ### Claim 2 (depends on 1) The electrical distribution system according to claim 1, wherein the threshold angle is comprised in an interval between 5° and 10°. ### Claim 3 (depends on 1) The electrical distribution system according to claim 1, wherein the electronic controller is further configured to activate the battery energy storage system to supply electric power to the electric load using the battery, and wherein opening the electrical switchgear device to disconnect the grid power source from the feeder and activating the battery energy storage system to supply electric power to the electric load using the battery are performed simultaneously or concurrently. ### Claim 4 (depends on 1) The electrical distribution system according to claim 1, wherein the battery energy storage system is configured to remain in the virtual-synchronous generator control mode. ### Claim 5 (depends on 1) The electrical distribution system according to claim 1, wherein the electronic controller is further configured to activate the battery energy storage system to supply electric power to the electric load using the battery, and wherein, after activating the battery energy storage system to supply electric power to the electric load using the battery, the battery energy storage system is configured to operate in a grid-forming mode. ### Claim 6 (depends on 1) The electrical distribution system according to claim 1, wherein the electronic controller is also configured to reconnect the electrical distribution system to the grid power source when power is restored to the grid power source after a power loss event. ### Claim 7 A method for disconnecting a grid power source from an electrical distribution system configured to supply electric power to an electric load, the electrical distribution system comprising a feeder for connecting at least one electric load, a battery energy storage system connected to the feeder, and a connection point for connecting a grid power source to the feeder, the battery energy storage system comprising a battery, an electrical switchgear device and an electronic controller, the electrical switchgear device being configured to selectively connect the connection point to the feeder, wherein the electronic controller is configured to implement a virtual-synchronous generator control mode, and comprising: detecting an electric fault, upon detecting an electric fault, automatically opening the electrical switchgear device to disconnect the grid power source from the feeder, and ensuring that the battery energy storage system supplies electric power to the electric load while operating in a virtual-synchronous generator control mode, wherein detecting an electric fault comprises detecting a voltage vector shift in voltage delivered by the grid power source, and wherein detecting the voltage vector shift in the voltage delivered by the grid power source comprises: measuring a duration of each cycle of the voltage delivered by the grid power source for each electrical phase, comparing a duration of a current voltage cycle with a duration of a previous voltage cycle, identifying a change in a voltage vector angle, and identifying that a power loss condition has occurred if the change of the voltage vector angle exceeds a predefined threshold angle value. ### Claim 8 (depends on 7) The method according to claim 7, wherein the threshold angle is comprised in an interval between 5° and 10°. ### Claim 9 (depends on 7) The method according to claim 7, further comprising activating the battery energy storage system to supply electric power to the electric load using the battery, and wherein opening the electrical switchgear device to disconnect the grid power source from the feeder and activating the battery energy storage system to supply electric power to the electric load using the battery are performed simultaneously or concurrently. ### Claim 10 (depends on 7) The method according to claim 7, wherein the battery energy storage system is configured to remain in the virtual-synchronous generator control mode. ### Claim 11 (depends on 7) The method according to claim 7, further comprising activating the battery energy storage system to supply electric power to the electric load using the battery, and wherein, after activating the battery energy storage system to supply electric power to the electric load using the battery, the battery energy storage system is configured to operate in a grid-forming mode. ### Claim 12 (depends on 7) The method according to claim 7, further comprising reconnecting the electrical distribution system to the grid power source when power is restored to the grid power source after a power loss event. ### Claim 13 (depends on 7) A computer program product comprising a non-transitory computer-readable medium having computer-executable code stored thereon, which when executed by a processor, causes the method according to claim 7 to be performed.