# US 11,299,056 B2 · System and method for charger contactor double weld detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,056 B2 - Document ID: US11299056B2 - Status: Granted - Kind: B2 - Application number: 16/707,770 - Filed: 2019-12-09 - Published: 2021-06-10 - Granted: 2022-04-12 - Earliest claimed: 2019-12-09 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Rui Wang; Aaron Walker; Yuan Zhang - Web page: https://patentgrep.com/patent/US11299056B2 ## CPC - B60L 53/62: in response to charging parameters, e.g. current, voltage or electrical charge - B60L 3/0023: {Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train} - B60L 3/0069: {relating to the isolation, e.g. ground fault or leak current} - B60L 3/0092: {with use of redundant elements for safety purposes} - B60L 3/04: Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) - B60L 58/12: responding to state of charge [SoC] - B60L 58/20: having different nominal voltages - G01R 31/3275: {Fault detection or status indication} - 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)} - H02J 7/62: against overcurrent - H02J 7/82: Control of state of charge [SOC] - H02J 7/96: in response to battery voltage - B60L 2240/80: Time limits - H02H 3/207: {also responsive to under-voltage (window comparators for indication G01R19/165)} - H02J 7/663: {using battery or load disconnect circuits (H02J9/002 takes precedence)} - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors - Y02T 90/12: Electric charging stations - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - 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) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A vehicle includes charger contactors configured to selectively electrically couple terminals for connecting to a charger to corresponding terminals of a high-voltage bus. The vehicle includes a precharge contactor configured to selectively couple a terminal of a battery to the high-voltage bus through an impedance element. The vehicle includes a controller programmed to command the charger contactors to an open state for a drive cycle and command the precharge contactor to close at a start of the drive cycle and, responsive to a voltage across the terminals for connecting to the charger changing from being less than a first predetermined voltage immediately prior to the precharge contactor being closed to being greater than a second predetermined voltage at a completion of precharging, inhibit vehicle operation and disconnect the battery from the high-voltage bus. ## Claims ### Claim 1 A vehicle comprising: charger contactors configured to selectively electrically couple terminals for connecting to a charger to corresponding terminals of a high-voltage bus; a precharge contactor configured to selectively couple a battery to the high-voltage bus through an impedance element; and a controller programmed to, at a start of a drive cycle, command the charger contactors to open and then command the precharge contactor to close for charging the high-voltage bus to a predetermined bus voltage and, responsive to a voltage across the terminals for connecting to the charger changing from being less than a first predetermined voltage immediately prior to the precharge contactor being closed to being greater than a second predetermined voltage when the high-voltage bus is charged to the predetermined bus voltage, command the precharge contactor to open and command a main contactor coupled between the battery and the high-voltage bus to remain open to disconnect the battery from the high-voltage bus and prevent vehicle operation. ### Claim 2 (depends on 1) The vehicle of claim 1, wherein the first predetermined voltage is a threshold indicative of the voltage being approximately zero. ### Claim 3 (depends on 1) The vehicle of claim 1, wherein the second predetermined voltage is a threshold indicative of the voltage being at a high-voltage level. ### Claim 4 (depends on 1) The vehicle of claim 1, wherein the controller is further programmed to, responsive to a voltage across the high-voltage bus being greater than the second predetermined voltage and the voltage across terminals for connecting to the charger being greater than the second predetermined voltage prior to the precharge contactor being closed, command the precharge contactor to open and command the main contactor to remain open to inhibit vehicle operation and prevent connection of the battery to the high-voltage bus. ### Claim 5 (depends on 1) The vehicle of claim 1, wherein the controller is further programmed to output a diagnostic code indicative of a double weld contactor condition responsive to inhibiting vehicle operation. ### Claim 6 (depends on 1) The vehicle of claim 1, wherein the controller is programmed to, responsive to the voltage being less than the first predetermined voltage immediately prior to the precharge contactor being closed and the voltage being less than the second predetermined voltage when the high-voltage bus is charged to the predetermined bus voltage, command the main contactor to close and command the precharge contactor to open. ### Claim 7 (depends on 1) The vehicle of claim 1, wherein the controller is further programmed to, responsive to a difference between a first voltage measured across the terminals for connecting to the charger while the precharge contactor is closed and a second voltage measured across the terminals for connecting to the charger immediately prior to closing the precharge contactor being greater than a threshold for a predetermined time, command the precharge contactor to open and command the main contactor to remain open to prevent connection of the battery to the high-voltage bus. ### Claim 8 A vehicle comprising: charger contactors configured to selectively electrically couple positive and return terminals for connecting to a charger to corresponding terminals of a high-voltage bus; a precharge contactor configured to selectively couple a battery to the high-voltage bus through an impedance element; and a controller programmed to, at a start of a drive cycle, command the charger contactors to open and then command the precharge contactor to close, and, responsive to a difference between a first voltage measured across the positive and return terminals when the precharge contactor is closed and a second voltage measured across the positive and return terminals immediately prior to closing the precharge contactor being greater than a predetermined threshold, command the precharge contactor to open and command a main contactor coupled between the battery and the high-voltage bus to remain open to prevent connection of the battery to the high-voltage bus. ### Claim 9 (depends on 8) The vehicle of claim 8, Wherein the predetermined threshold is indicative of the difference increasing during precharging. ### Claim 10 (depends on 8) The vehicle of claim 8, wherein the controller is further programmed to output a diagnostic code indicative of a double weld contactor condition responsive to inhibiting vehicle operation. ### Claim 11 (depends on 8) The vehicle of claim 8, herein the controller is further programmed to, responsive to the difference being less than the predetermined threshold for a duration of precharging, command the main contactor to close and command the precharge contactor to open. ### Claim 12 (depends on 8) The vehicle of claim 8, wherein the controller is further programmed to, responsive to voltage across the high-voltage bus being greater than a predetermined voltage and voltage across terminals for connecting to the charger being greater than the predetermined voltage prior to the precharge contactor being closed, command the precharge contactor to open and command the main contactor to remain open to prevent connection of the battery to the high-voltage bus and inhibit vehicle operation. ### Claim 13 (depends on 12) The vehicle of claim 12, wherein the predetermined voltage is a threshold indicative of voltage across terminals for connecting to the charger exceeding a high-voltage level. ### Claim 14 A method comprising: commanding, by a controller, charger contactors disposed between terminals for connecting to a charger to corresponding terminals of a high-voltage bus to open at a start of a drive cycle; commanding, by a controller, a precharge contactor that couples a traction battery to a high-voltage bus through an impedance to close for charging the high-voltage bus to a predetermined bus voltage; and commanding, by the controller, the precharge contactor to open and commanding a main contactor coupled between the traction battery and the high-voltage bus to remain open responsive to a voltage across the terminals for connecting to the charger changing from being less than a first predetermined voltage immediately prior to the precharge contactor being closed to being greater than a second predetermined voltage when the high-voltage bus is charged to the predetermined bus voltage. ### Claim 15 (depends on 14) The method of claim 14 further comprising outputting, by the controller, a diagnostic code indicative of a double weld contactor condition. ### Claim 16 (depends on 14) The method of claim 14, wherein the first predetermined voltage is a threshold indicative of the voltage being approximately zero. ### Claim 17 (depends on 14) The method of claim 14, wherein the second predetermined voltage is a threshold indicative of the voltage being at a high-voltage level. ### Claim 18 (depends on 14) The method of claim 14 further comprising commanding, by the controller, the precharge contactor to open and commanding a main contactor coupled between the traction battery and the high-voltage bus to remain open responsive to a voltage across the high-voltage bus being greater than the second predetermined voltage and the voltage across terminals for connecting to the charger being greater than the second predetermined voltage prior to the precharge contactor being closed. ### Claim 19 (depends on 14) The method of claim 14 further comprising commanding, by the controller, the main contactor to close and commanding the precharge contactor to open, both responsive to the voltage being less than the first predetermined voltage immediately prior to the precharge contactor being closed and the voltage being less than the second predetermined voltage when the high-voltage bus is charged to the predetermined bus voltage. ### Claim 20 (depends on 14) The method of claim 14 further comprising, responsive to a difference between a first voltage measured across the terminals for connecting to a charger while the precharge contactor is closed and a second voltage measured across the for connecting to a charger immediately prior to closing the precharge contactor being greater than a threshold for a predetermined time, commanding the precharge contactor to open and command the main contactor to remain open to prevent connection of the traction battery to the high-voltage bus.