System and method for energy management in an electric vehicle
First Claim
1. A system comprising:
- a vehicle;
a power system onboard the vehicle and configured to provide power to drive the vehicle, the power system comprising;
a traction drive including an inverter and an AC motor;
a direct current (DC) link electrically coupled to the traction drive;
a high specific-power energy storage device (power ESD) electrically coupled to the traction drive to provide power thereto; and
a high specific-energy energy storage device (energy ESD) electrically coupled to the traction drive to provide power thereto; and
an energy management system (EMS) configured to;
determine a net total power of the vehicle, the net total power comprising a sum of a traction drive load demand, an auxiliary device load demand, and a regenerative power provided by regenerative braking of the traction drive;
cause regenerative power to be provided to each of the power ESD and the energy ESD if the net total power comprises a net supply power, with providing of the net supply power being controlled so as to initially charge the power ESD to a desired state-of-charge (SOC) and subsequently charge the energy ESD;
cause power to be drawn from the power ESD and the energy ESD if the net total power comprises a net power load, with a split of the power being drawn from the power ESD and the energy ESD such that power is drawn only from the energy ESD if the net power load is below a power load threshold and power is drawn from both the power ESD and energy ESD if the net power load is above the power load threshold;
maintain a desired voltage on the DC link based on a speed of the AC motor; and
maintain a desired SOC of the power ESD based on a speed and a relative altitude or slope of travel of the vehicle.
1 Assignment
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Accused Products
Abstract
A vehicular energy management system (EMS) determines a net total power from a traction drive load, an auxiliary device load, and a regenerative power. If the net total power is a net supply power, the EMS causes regenerative power to be provided to a power source and energy source in a controlled manner to initially charge the power source to a desired state-of-charge (SOC) and then subsequently charge the energy source. If the net total power comprises a net power load, the EMS causes power to be drawn from the power source and the energy source, with a split of the power being drawn from the power source and the energy source being based on a magnitude of the net power load. The EMS adjusts/maintains the SOC set-point of the power source and the DC link voltage based on vehicle speed and relative altitude of travel of the vehicle.
36 Citations
24 Claims
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1. A system comprising:
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a vehicle; a power system onboard the vehicle and configured to provide power to drive the vehicle, the power system comprising; a traction drive including an inverter and an AC motor; a direct current (DC) link electrically coupled to the traction drive; a high specific-power energy storage device (power ESD) electrically coupled to the traction drive to provide power thereto; and a high specific-energy energy storage device (energy ESD) electrically coupled to the traction drive to provide power thereto; and an energy management system (EMS) configured to; determine a net total power of the vehicle, the net total power comprising a sum of a traction drive load demand, an auxiliary device load demand, and a regenerative power provided by regenerative braking of the traction drive; cause regenerative power to be provided to each of the power ESD and the energy ESD if the net total power comprises a net supply power, with providing of the net supply power being controlled so as to initially charge the power ESD to a desired state-of-charge (SOC) and subsequently charge the energy ESD; cause power to be drawn from the power ESD and the energy ESD if the net total power comprises a net power load, with a split of the power being drawn from the power ESD and the energy ESD such that power is drawn only from the energy ESD if the net power load is below a power load threshold and power is drawn from both the power ESD and energy ESD if the net power load is above the power load threshold; maintain a desired voltage on the DC link based on a speed of the AC motor; and maintain a desired SOC of the power ESD based on a speed and a relative altitude or slope of travel of the vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for optimizing energy storage component usage in a vehicle comprising one of a hybrid vehicle, a plug-in hybrid vehicle, and an electric vehicle, the system comprising an energy management system (EMS) programmed to:
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determine a net total power of the vehicle, the net total power comprising a combination of an inverter load demand for driving a traction drive, an auxiliary load demand, and a regenerative power provided by regenerative braking of the traction drive; determine if the net total power comprises a net supply power or a net power load; if the net total power comprises a net supply power, then cause the net supply power to be provided to each of a power source and an energy source in the vehicle that provide traction power, wherein the net supply power is first supplied to the power source so as to bring the power source to a state-of-charge (SO C) set-point and is then subsequently supplied to the energy source; if the net total power comprises a net power load, then; compare the net power load to at least one power load threshold; and control a drawing of power from the power source and the energy source to meet the inverter and auxiliary load demands such that power is drawn only from the power source if the net power load is below a power load threshold and power is drawn from both the power source and energy source if the net power load is above the power load threshold; maintain a desired voltage on a DC link in the vehicle based on a speed of a motor in the traction drive; and maintain the power source at the SOC set-point, which is adjusted based on a speed of the vehicle and an altitude and grade of terrain the vehicle is traveling on. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A method for optimizing energy storage component usage in a vehicle having a high specific-power energy storage device (ESD) and a high specific-energy ESD coupled to a traction drive by way of a direct current (DC) link, the method comprising:
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determining a desired operating voltage for the DC link in the vehicle based on a speed of a motor in the traction drive; determining a state-of-charge (SOC) set-point for the high specific-power ESD based on a speed of the vehicle and an altitude of the road being traveled by the vehicle; determining a power state of the vehicle based on a summation of a traction drive load demand, an auxiliary device load demand, and a regenerative power supply provided by regenerative braking of the traction drive, the power state comprising a net power supply or a net power load; selectively providing a charging power to the high specific-power ESD and the high specific-energy ESD if the vehicle has a net power supply, wherein charging power is provided so as to initially charge the high specific-power ESD to the determined SOC set-point before charging the high specific-energy ESD; and selectively drawing power from the high specific-power ESD and the high specific-energy ESD if the vehicle has a net power load, wherein power is drawn from the high specific-power ESD and the high specific-energy ESD such that power is drawn only from the energy ESD if the net power load is below a power load threshold and power is drawn from both the power ESD and energy ESD if the net power load is above the power load threshold. - View Dependent Claims (20, 21, 22, 23)
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24. A system comprising:
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a vehicle; a power system onboard the vehicle and configured to provide power to drive the vehicle, the power system comprising; a traction drive including an inverter and an AC motor; a direct current (DC) link electrically coupled to the traction drive; a high specific-power energy storage device (power ESD) electrically coupled to the traction drive to provide power thereto; and a high specific-energy energy storage device (energy ESD) electrically coupled to the traction drive to provide power thereto; and an energy management system (EMS) configured to; determine a net total power of the vehicle, the net total power comprising a sum of a traction drive load demand, an auxiliary device load demand, and a regenerative power provided by regenerative braking of the traction drive; cause regenerative power to be provided to each of the power ESD and the energy ESD if the net total power comprises a net supply power, with providing of the net supply power being controlled so as to initially charge the power ESD to a desired state-of-charge (SOC) and subsequently charge the energy ESD; and cause power to be drawn from the power ESD and the energy ESD if the net total power comprises a net power load, with a split of the power being drawn from the power ESD and the energy ESD such that power is drawn only from the energy ESD if the net power load is below a power load threshold and power is drawn from both the power ESD and energy ESD if the net power load is above the power load threshold.
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Specification