DC bus voltage regulation in automotive vehicle during contactor open events
A vehicle power system includes a battery bus between a traction battery and voltage converter, a high-voltage bus between the voltage converter and an inverter, and a controller. The controller, responsive to a contactor between the traction battery and voltage converter opening, controls an engine to maintain a speed of a generator electrically coupled with the inverter within a predefined range, controls the voltage converter to drive a measured voltage of the battery bus toward a first commanded value based on a first difference between the first commanded value and measured voltage of the battery bus, and controls the generator to drive a measured voltage of the high-voltage bus toward a second commanded value different than the first commanded value based on the first difference and a second difference between the second commanded value and the measured voltage of the high-voltage bus.
1. A vehicle comprising:
a drive system including an engine, a generator, wheels, and gears mechanically coupling the engine, generator, and wheels;
a power system including a traction battery, a voltage converter, a battery bus between the voltage converter and traction battery, a first inverter, and a high-voltage bus between the first inverter and voltage converter; and
a controller programmed to, responsive to power from the traction battery becoming unavailable,
control the engine to maintain a speed of the generator within a predefined range,
control the voltage converter to drive a measured voltage of the battery bus toward a first commanded value based on a first difference between the first commanded value and measured voltage of the battery bus, and
control the generator to drive a measured voltage of the high-voltage bus toward a second commanded value different than the first commanded value based on the first difference and a second difference between the second commanded value and the measured voltage of the high-voltage bus.
2. The vehicle of claim 1 , wherein the drive system further includes a traction motor and wherein the gears mechanically couple the traction motor and wheels.
3. The vehicle of claim 2 , wherein the gears are configured such that the engine and traction motor can propel the wheels to move the vehicle.
4. The vehicle of claim 2 further comprising a second inverter between the high-voltage bus and traction motor and in parallel with the first inverter.
5. The vehicle of claim 1 , wherein a third difference between the first and second commanded values exceeds 50 volts.
6. The vehicle of claim 1 , wherein the predefined range is between 2000 and 9000 rpm.
7. The vehicle of claim 1 , wherein the power system further includes a contactor between the traction battery and battery bus and wherein power from the traction battery becoming unavailable is defined by the contactor being open.
8. A method for controlling a vehicle comprising:
responsive to power from a traction battery becoming unavailable,
controlling an engine to maintain a speed of a generator mechanically coupled therewith within a predefined range,
controlling a voltage converter to drive a measured voltage of a battery bus between the traction battery and a voltage converter toward a first commanded value based on a first difference between the first commanded value and measured voltage of the battery bus, and
controlling, the generator to drive a measured voltage of a high-voltage bus between the voltage converter and generator toward a second commanded value different than the first commanded value based on the first difference and a second difference between the second commanded value and the measured voltage of the high-voltage bus.
9. The method of claim 8 further comprising propelling the vehicle with power from the engine, power from a traction motor, or power from the engine and traction motor.
10. The method of claim 8 , wherein a third difference between the first and second commanded values exceeds 50 volts.
11. The method of claim 8 , wherein the predefined range is between 2000 and 9000 rpm.
12. The method of claim 8 , wherein power from the traction battery becoming unavailable is defined by a contactor between the traction battery and voltage converter being open.
13. A vehicle power system comprising:
a battery bras between a traction battery and voltage converter;
a high-voltage bus between the voltage converter and a first inverter; and
a controller programmed to, responsive to a contactor between the traction battery and voltage converter opening,
control an engine to maintain a speed of a generator electrically coupled with the first inverter within a predefined range,
control the voltage converter to drive a measured voltage of the battery bus toward a first commanded value based on a first difference between the first commanded value and measured voltage of the battery bus, and
control the generator to drive a measured voltage of the high-voltage bus toward a second commanded value different than the first commanded value based on the first difference and a second difference between the second commanded value and the measured voltage of the high-voltage bus.
14. The vehicle power system of claim 13 , wherein a third difference between the first and second commanded values exceeds 50 volts.
15. The vehicle power system of claim 13 , wherein the predefined range is between 2000 and 9000 rpm.