# US 12,594,839 B2 · Electrified vehicle low-voltage (LV) bus voltage control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,594,839 B2 - Document ID: US12594839B2 - Status: Granted - Kind: B2 - Application number: 17/969,858 - Filed: 2022-10-20 - Published: 2024-04-25 - Granted: 2026-04-07 - Earliest claimed: 2022-10-20 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Hanyang Chen; Michael J Irby - Web page: https://patentgrep.com/patent/US12594839B2 ## CPC - B60L 15/20: for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed - B60L 50/60: using power supplied by batteries (in combination with fuel cells B60L50/75) - B60W 10/06: including control of combustion engines - B60W 10/08: including control of electric propulsion units, e.g. motors or generators - B60W 10/26: for electrical energy, e.g. batteries or capacitors - G07C 5/0808: {Diagnosing performance data (testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005)} - G07C 5/0825: {using optical means} - B60L 58/20: having different nominal voltages - B60L 2210/10: DC to DC converters - B60L 2250/16: by display - B60L 2250/26: by pedal actuation - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - 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 - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An electrified vehicle includes a traction battery coupled to an electric machine that provides propulsive force, an auxiliary battery, a voltage converter coupled to the traction battery and configured to convert traction battery voltage to auxiliary battery voltage, and a controller programmed to control the voltage converter to provide either a non-oscillating voltage above a first voltage threshold, or an oscillating voltage having a peak below the first voltage threshold based on a vehicle start signal and a vehicle brake pedal position signal. The controller may control the voltage converter to provide the non-oscillating voltage in response to the vehicle start signal being received while the brake pedal position signal indicates a released brake pedal, and to provide the oscillating voltage in response to the vehicle start signal being received while the brake pedal position signal indicates a depressed brake pedal. ## Claims ### Claim 1 An electrified vehicle comprising: an electric machine powered by a high-voltage battery; a voltage converter coupled to the high-voltage battery and a low-voltage auxiliary battery; and a controller programmed to control the voltage converter to provide an output voltage greater than a first voltage threshold to the low-voltage auxiliary battery in response to a vehicle start signal received while a brake pedal is depressed, and to provide an oscillating output voltage with a peak amplitude less than the first voltage threshold to the low-voltage auxiliary battery in response to the vehicle start signal being received while the brake pedal is released; wherein the controller is further programmed to generate a diagnostic signal in response to current of the low-voltage auxiliary battery being less than a first current threshold when the output voltage is above the first voltage threshold. ### Claim 2 (depends on 1) The electrified vehicle of claim 1 further comprising a human-machine interface (HMI), wherein the HMI generates an alert in response to the diagnostic signal. ### Claim 3 (depends on 1) The electrified vehicle of claim 1 wherein the controller is further programmed to generate a diagnostic signal in response to current variation of the low voltage auxiliary battery being less than a second current threshold when the voltage converter is providing the oscillating output voltage. ### Claim 4 (depends on 1) The electrified vehicle of claim 1 wherein the controller controls the voltage converter to provide the oscillating voltage with an oscillation frequency of 1 Hz. ### Claim 5 (depends on 1) The electrified vehicle of claim 1 wherein the controller controls the voltage converter to provide the oscillating voltage with a peak-to-peak amplitude of less than 2% of a predetermined target voltage associated with the low-voltage auxiliary battery. ### Claim 6 (depends on 1) The electrified vehicle of claim 1 wherein the voltage converter comprises a DC/DC converter and wherein the controller communicates an oscillating target voltage command to the DC/DC converter to provide the oscillating output voltage. ### Claim 7 A method for controlling an electrified vehicle having a high-voltage traction battery coupled by a voltage converter to a low-voltage auxiliary battery, comprising, by a vehicle controller: controlling the voltage converter to provide an oscillating output voltage to the low-voltage auxiliary battery in response to receiving a start signal while a vehicle brake pedal is released; and generating a diagnostic signal in response to variation of current supplied to the low-voltage auxiliary battery being less than a first current variation threshold; controlling the voltage converter to provide an output voltage greater than a first voltage threshold in response to receiving the start signal while the vehicle brake pedal is depressed; and generating the diagnostic signal in response to the current supplied to the low-voltage auxiliary battery being less than a first current threshold when the output voltage is above the first voltage threshold. ### Claim 8 (depends on 7) The method of claim 7 wherein the oscillating output voltage has a maximum voltage less than the first voltage threshold. ### Claim 9 (depends on 7) The method of claim 7 wherein generating the diagnostic signal is performed after the current supplied to the low-voltage auxiliary battery is less than the first current threshold for a predetermined period of time. ### Claim 10 (depends on 7) The method of claim 7 wherein the voltage converter comprises a DC/DC converter and wherein controlling the voltage converter to provide an oscillating output voltage comprises generating an oscillating target command voltage communicated to the DC/DC converter. ### Claim 11 (depends on 7) The method of claim 7 wherein the oscillating output voltage has a frequency of 1 Hz and a peak-to-peak amplitude of less than 5% of a predetermined target voltage associated with the low-voltage auxiliary battery. ### Claim 12 (depends on 7) The method of claim 7 further comprising communicating an alert to a vehicle human-machine interface (HMI) in response to the diagnostic signal. ### Claim 13 (depends on 7) The method of claim 7 wherein generating the diagnostic signal is performed after the current supplied to the low-voltage auxiliary battery is less than the first current variation threshold for a predetermined period of time. ### Claim 14 A system comprising: a traction battery coupled to an electric machine that provides propulsive force to an electrified vehicle; an auxiliary battery; a voltage converter coupled to the traction battery and configured to convert traction battery voltage to auxiliary battery voltage; and a controller programmed to: control the voltage converter to provide a non-oscillating voltage above a first voltage threshold to the auxiliary battery in response to the vehicle start signal being received while the brake pedal position signal indicates a released brake pedal, and an oscillating voltage having a peak below the first voltage threshold based on a in response to the vehicle start signal being received while the brake pedal position signal indicates a depressed brake pedal; wherein the controller is further programmed to generate a diagnostic signal in response to current to the auxiliary battery being below a corresponding current threshold while the voltage converter provides the non-oscillating voltage. ### Claim 15 (depends on 14) The system of claim 14 wherein the controller is further programmed to generate a diagnostic signal in response to variation of current to the auxiliary battery being below a corresponding current variation threshold while the voltage converter provides the oscillating voltage.