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US 12,454,200 B2Granted
Back electromotive force management for electric vehicles
AssigneeGM Global Technology Operations LLC
InventorsChristopher Lyman Jones, Todd M. York, Anthony H. Heap
Life of this patent
Estimating the term…
Abstract
An electric vehicle battery control system including a first electric motor configured to propel a vehicle in a drive mode in response to a drive current, a second electric motor operative to generate a back electromotive force voltage in a fault mode, a battery, having an open circuit battery discharge voltage, for generating the drive current for coupling to the first electric motor, and a vehicle controller for limiting the drive current in response to a difference between the back electromotive force voltage and the open circuit battery discharge voltage being less than a threshold voltage difference.
Claims20
A propulsion system comprising:
- a first electric motor configured to propel a vehicle in a drive mode in response to a first drive current, wherein the first electric motor is mechanically coupled to a first wheel and wherein the vehicle is propelled in response to a rotation of the first wheel;
- a second electric motor operative to propel the vehicle in the drive mode in response to a second drive current, wherein the second electric motor is mechanically coupled to a second wheel and wherein the vehicle is propelled in response to a rotation of the second wheel, and wherein the second electric motor generates a back electromotive force voltage in response to a rotation of the second wheel resulting from a propulsion of the vehicle by the first electric motor when the second electric motor is in a fault mode;
- a battery, having an open circuit battery discharge voltage, for generating the first drive current for coupling to the first electric motor;
- and
- a vehicle controller for limiting the first drive current in response to a difference between the back electromotive force voltage and the open circuit battery discharge voltage being less than a threshold voltage difference, wherein the first drive current is limited in response to a limiting of the operation motor torque such that the back electromotive force voltage is kept below the open circuit battery discharge voltage.
2 more elements
A method of controlling a rechargeable energy storage propulsion system comprising:
- propelling a vehicle in a drive mode in response to a first drive current using a first electric motor mechanically coupled to a first wheel and wherein the vehicle is propelled in response to a rotation of the first wheel;
- generating a back electromotive force voltage by a second electric motor mechanically coupled to a second wheel and wherein the second electric motor generates the back electromotive force voltage in response to a rotation of the second wheel resulting from a propulsion of the vehicle by the first electric motor;
- determining a vehicle speed in response to a rotational speed of the first electric motor detected by a rotational sensor;
- determining, by a battery management system, a battery output voltage;
- and
- limiting a motor torque to the first electric motor, in response to a difference between the back electromotive force voltage and the battery output voltage being less than a threshold difference, wherein the first drive current is limited in response to a limiting of the motor torque such that the back electromotive force voltage is kept below the battery output voltage.
3 more elements
A rechargeable energy storage system propulsion control system comprising:
- a first electric motor configured to configured to propel a vehicle in response to a first drive current, wherein the first electric motor is mechanically coupled to a first wheel and wherein the vehicle is propelled in response to a rotation of the first wheel;
- a second electric motor configured to propel the vehicle in response to a second drive current and operative to generate a back electromotive force voltage in during a fault state, wherein the second electric motor is mechanically coupled to a second wheel and wherein the vehicle is propelled in response to a rotation of the second wheel and wherein the back electromotive force voltage is generated in response to a rotation of the second wheel resulting from a propulsion of the vehicle by the first electric motor;
- a battery for storing an electric charge for generating the first drive current and the second drive current, wherein the battery has an open circuit battery discharge voltage;
- and
- a controller, including a processor, configured for limiting the first drive current in response to a difference between the open circuit battery discharge voltage and the back electromotive force voltage being less than a threshold difference, wherein the first drive current is limited in response to a limiting of the operation motor torque such that the back electromotive force voltage is kept below the open circuit battery discharge voltage.
2 more elements
Dependencies are inferred from the claim text.