# US 2023/0054823 A1 · System and method for recirculating power > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0054823 A1 - Document ID: US20230054823A1 - Status: Published application - Kind: A1 - Application number: 17/445,567 - Filed: 2021-08-20 - Published: 2023-02-23 - Earliest claimed: 2021-08-20 - Assignees: Dana Heavy Vehicle Systems Group, LLC - Applicants: Dana Heavy Vehicle Systems Group, LLC - Inventors: Jeffrey M. DAVID - Web page: https://patentgrep.com/patent/US20230054823A1 ## CPC - B60L 15/2045: {for optimising the use of energy} - B60K 1/00: Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) - B60K 7/0007: {the motor being electric} - B60K 17/354: having separate mechanical assemblies for transmitting drive to the front or to the rear wheels or set of wheels - B60K 17/356: having fluid or electric motor, for driving one or more wheels - 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 15/2009: {for braking} - B60L 58/13: Maintaining the SoC within a determined range - B60K 17/36: for driving tandem wheels - B60K 2001/001: {one motor mounted on a propulsion axle for rotating right and left wheels of this axle} - B60K 2007/0038: {the motor moving together with the wheel axle} - B60K 2007/0092: {the motor axle being coaxial to the wheel axle} - B60L 2220/42: with use of more than one motor - B60L 2260/26: Transition between different drive modes - 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 - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES ## Abstract Methods and systems for operating a driveline that includes two electric machines are described. In one example, one electric machine is operated in a generator mode and the other electric machine is operated in a motor mode so that electric power that is generated by the electric machine that is operated in the generator mode is consumed by the electric machine that is operated in the motor mode. ## Claims ### Claim 1 A method for operating a vehicle, comprising: operating a first electric machine in a motor mode; operating a second electric machine in a generator mode, while operating the first electric machine in the motor mode, and while a net power amount exchanged between an electric energy storage device and the first electric machine and the second electric machine is substantially zero. ### Claim 2 (depends on 1) The method of claim 1, where the first electric machine is coupled to a first axle and the second electric machine is coupled to a second axle. ### Claim 3 (depends on 1) The method of claim 1, where the first electric machine and the second electric machine are coupled to a vehicle's front wheels, or where the first electric machine and the second electric machine are coupled to the vehicle's rear wheels. ### Claim 4 (depends on 1) The method of claim 1, where the electric energy storage device is a battery or a capacitor. ### Claim 5 (depends on 1) The method of claim 1, further comprising reducing a speed of the vehicle via the second electric machine while operating the first electric machine in the motor mode. ### Claim 6 (depends on 1) The method of claim 1, further comprising operating the first electric machine to consume electric power generated via the second electric machine. ### Claim 7 (depends on 1) The method of claim 1, further comprising operating the second electric machine in the generator mode and the first electric machine in the motor mode in response to a state of charge of the electric energy storage device. ### Claim 8 A vehicle system, comprising: a first electric machine; a second electric machine; an electric energy storage device; and a controller including executable instructions stored in non-transitory memory that cause the controller to operate the first electric machine in a motor mode and the second electric machine in a generator mode with the first electric machine consuming an entire amount of electric energy produced via the second electric machine. ### Claim 9 (depends on 8) The vehicle system of claim 8, further comprising a first gearbox coupled to the first electric machine and a second gearbox coupled to the second electric machine. ### Claim 10 (depends on 9) The vehicle system of claim 9, further comprising additional instructions to shift the first gearbox and the second gear box to provide a desired level of vehicle braking. ### Claim 11 (depends on 9) The vehicle system of claim 9, further comprising additional instructions to shift the second gearbox to a numerically higher gear ratio than the first gearbox to increase vehicle braking torque. ### Claim 12 (depends on 8) The vehicle system of claim 8, where the first electric machine is coupled to a first axle including a first final drive gear set, and where the second electric machine is coupled to a second axle. ### Claim 13 (depends on 12) The vehicle system of claim 12, where first final drive gear set has a different gear ratio than the second final drive gear set. ### Claim 14 (depends on 12) The vehicle system of claim 12, where the first axle is a rear axle and the second axle is a front axle. ### Claim 15 (depends on 8) The vehicle system of claim 8, where the first electric machine is operated in the motor mode and the second electric machine is operated in the generator mode in response to a temperature of the electric energy storage device. ### Claim 16 A method for operating a vehicle, comprising: reducing a speed of the vehicle via a second electric machine in response to a braking request without providing electric power from the second electric machine to an electric energy storage device. ### Claim 17 (depends on 16) The method of claim 16, further comprising a first electric machine consuming electric power generated by the second electric machine while reducing the speed of the vehicle via the second electric machine. ### Claim 18 (depends on 16) The method of claim 16, wherein the second electric machine is operated in a generator mode. ### Claim 19 (depends on 16) The method of claim 16, further comprising adjusting a gear ratio of a gearbox to adjust an efficiency of the second electric machine, the gearbox coupled to the second electric machine. ### Claim 20 (depends on 16) The method of claim 16, further comprising reducing the speed of the vehicle via the second electric machine in response to a temperature of the electric energy storage device.