# US 11,994,560 B1 · Relay monitoring for electrical systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,560 B1 - Document ID: US11994560B1 - Status: Granted - Kind: B1 - Application number: 18/185,279 - Filed: 2023-03-16 - Granted: 2024-05-28 - Earliest claimed: 2023-03-16 - Assignees: Rivian IP Holdings, LLC - Applicants: Rivian IP Holdings, LLC - Inventors: Muhammad Mobeen Mahmood - Web page: https://patentgrep.com/patent/US11994560B1 ## CPC - G01R 31/3278: {of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002)} - G01R 19/0038: {Circuits for comparing several input signals and for indicating the result of this comparison, e.g. equal, different, greater, smaller (comparing pulses or pulse trains according to amplitude)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Aspects of the disclosure relate to relay monitoring for electrical systems. An electrical system may include one or more relays, such as steering relays, that switchably couple separate portions of the electrical system. By exercising the relay(s) and measuring voltages on opposite sides of the relay, it may be determined whether the relay is healthy. ## Claims ### Claim 1 An apparatus, comprising: an electrical system, comprising: a relay having a pole that is coupled to power electronics of the apparatus and that is switchably couplable to: a first contact that is coupled to a power source terminal, and a second contact that is coupled to a load terminal; and control circuitry configured to, prior to energizing the power electronics: exercise the relay to connect the pole to the first contact; determine that a first voltage at the first contact of the relay is equal to a second voltage at the pole of the relay; exercise the relay to connect the pole to the second contact; obtain a third voltage at the second contact of the relay and a fourth voltage at the pole of the relay; and determine whether the relay has a fault based on a comparison of the third voltage and the fourth voltage. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the power source terminal is coupled to a power source external to the apparatus. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein the power source external to the apparatus comprises an electrical grid. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the load terminal comprises an electrical outlet. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the apparatus comprises a vehicle. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the control circuitry is configured to determine whether the relay has a fault by: determining, based on the comparison, that the third voltage is different from the fourth voltage; and determining that the relay has the fault based on the determination that the third voltage is different from the fourth voltage. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the control circuitry is configured to determine whether the relay has a fault by: determining, based on the comparison, that the third voltage is substantially the same as the fourth voltage; exercising the relay to again connect the pole to the first contact; obtaining an updated third voltage and an updated fourth voltage while the pole is again connected to the first contact; and determining that the relay is healthy based on a determination that the updated third voltage is different from the updated fourth voltage. ### Claim 8 (depends on 1) The apparatus of claim 1, further comprising at least one additional relay having a pole coupled to the power electronics, wherein the at least one additional relay is switchable between: an open position, and a closed position in which the pole is connected to a contact of the at least one additional relay, wherein the contact of the at least one additional relay is coupled to the load terminal, wherein the control circuitry is further configured to: open the at least one additional relay; and determine whether the at least one additional relay has a fault based on a comparison of a fifth voltage at the pole of the at least one additional relay and a sixth voltage at the contact of the at least one additional relay. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the control circuitry is configured to determine whether the at least one additional relay has a fault by: determining, while the at least one additional relay is open, that the fifth voltage is substantially the same as the sixth voltage; and determining that the at least one additional relay has the fault based on the determination that the fifth voltage is substantially the same as the sixth voltage. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the control circuitry is configured to determine whether the at least one additional relay has a fault by: determining, while the at least one additional relay is open, that the fifth voltage is different from the sixth voltage; and determining that the at least one additional relay is healthy based on the determination that the fifth voltage is different from the sixth voltage. ### Claim 11 (depends on 8) The apparatus of claim 8, wherein the control circuitry is further configured to determine, while the at least one additional relay is open, whether the at least one additional relay has the fault based on a comparison of a seventh voltage at the pole of the at least one additional relay and an eighth voltage at the contact of the at least one additional relay, the comparison performed while the relay is exercised to the second contact of the relay. ### Claim 12 A method, comprising: exercising a relay of an electrical system to connect a pole of the relay to a first contact of the relay, the pole of the relay coupled to power electronics of the electrical system; and prior to energizing the power electronics: determining that a first voltage at the first contact of the relay is equal to a second voltage at the pole of the relay; exercising the relay to connect the pole to a second contact of the relay; obtaining a third voltage at the second contact of the relay and a fourth voltage at the pole of the relay; and determining whether the relay has a fault based on a comparison of the third voltage and the fourth voltage. ### Claim 13 (depends on 12) The method of claim 12, wherein determining whether the relay has the fault comprises: determining, based on the comparison, that the third voltage is different from the fourth voltage; and determining that the relay has the fault based on the determination that the third voltage is different from the fourth voltage. ### Claim 14 (depends on 13) The method of claim 13, further comprising providing a notification responsive to determining that the relay has the fault based on the comparison of the third voltage and the fourth voltage. ### Claim 15 (depends on 12) The method of claim 12, determining whether the relay has a fault comprises: determining, based on the comparison, that the third voltage is substantially the same as the fourth voltage; exercising the relay to again connect the pole to the first contact; obtaining an updated third voltage and an updated fourth voltage while the pole is again connected to the first contact; and determining that the relay is healthy based on a determination that the updated third voltage is different from the updated fourth voltage. ### Claim 16 (depends on 15) The method of claim 15, further comprising providing power from a battery to a load terminal of the electrical system via the relay responsive to determining that the relay is healthy. ### Claim 17 (depends on 14) The method of claim 14, further comprising opening at least one additional relay of the electrical system; and determining whether the at least one additional relay has a fault based on a comparison of a fifth voltage at a pole of the at least one additional relay and a sixth voltage at a contact of the at least one additional relay. ### Claim 18 (depends on 17) The method of claim 17, further comprising determining whether the at least one additional relay has the fault based on a comparison of a seventh voltage at the pole of the at least one additional relay and an eighth voltage at the contact of the at least one additional relay, the comparison performed while the at least one additional relay is open and while the relay is exercised to the second contact of the relay. ### Claim 19 An electric vehicle, comprising: a relay having a pole that is coupled to power electronics of the electric vehicle and that is switchably couplable to: a first contact that is coupled to a power source terminal, and a second contact that is coupled to a load terminal; and control circuitry configured to, prior to energizing the power electronics: exercise the relay to connect the pole to the first contact; determine that a first voltage at the first contact of the relay is equal to a second voltage at the pole of the relay; exercise the relay to connect the pole to the second contact; obtain a third voltage at the second contact of the relay and a fourth voltage at the pole of the relay; and determine whether the relay has a fault based on a comparison of the third voltage and the fourth voltage. ### Claim 20 (depends on 19) The electric vehicle of claim 19, wherein the power source terminal is coupled to a power source external to the electric vehicle, and wherein the load terminal comprises an electrical outlet of the electric vehicle.