Operation of power electronics during battery communication loss

• US 10,286,899 B2
• Filed: 11/16/2016
• Issued: 05/14/2019
• Est. Priority Date: 11/16/2016
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Barkdull, Trent, Treharne, William David, Butcher, Jonathan Andrew
• Primary Examiner(s): Marc, McDieunel
• Application Number:
  US15/353,270
• Publication Number:
  US 20180134279A1
• Time in Patent Office: 909 Days
• CPC Class Codes: B60K 6/20 the prime-movers consisting of electric motors and internal combustion engines, e.g. HEVs
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/429 Current
• CPC Class Codes: B60L 2240/54 related to batteries
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 53/20 characterised by converters located in the vehicle
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60Y 2300/69 Motor boost, e.g. short time overpower
• CPC Class Codes: B60Y 2306/13 Failsafe arrangements
• CPC Class Codes: B60Y 2400/112 Batteries
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

A vehicle includes a battery control module and a controller. The battery control module is configured to issue at regular intervals a message indicative of a state of charge (SOC) of a battery. The controller is configured to, in an absence of receiving the messages at the regular intervals while in a key-on state and a torque demand is present, restrict power flow between the battery and an electric powertrain to a limit that is based on a predicted SOC to provide limited propulsive force.

Claims

1. A method of controlling an electric powertrain comprising:

in response to an absence of a state of charge (SOC) value of a battery broadcast by a battery module at a periodic interval,

limiting net power flow of the electric powertrain to maintain the SOC value to within a predetermined range that is based on a predicted SOC value of the battery,

diverting power between an accessory high-voltage load and the electric powertrain such that a change in power flow is minimized, and

commanding an electrical generating machine torque of the electric powertrain at an angular speed to a power equal to provide power propulsion demand and parasitic losses of the electric powertrain to diminish a change in net battery power.

2. The method of claim 1, wherein the predicted SOC value is based on a last received message, a period starting from the last received message to a present time, and a time integral of a power of a high-voltage bus between the battery and an electric machine over the period.

3. The method of claim 1, wherein diverting power between the electric powertrain and the accessory high-voltage load is, in response to an increase in power demand by the electric powertrain, diverting power from an accessory high-voltage load to the electric powertrain such that a change in power flow is minimized.

4. The method of claim 1, wherein limiting a torque of an electric machine includes limiting a propulsive force available from the electric machine.

5. A vehicle comprising:

a controller configured to,

responsive to absence of a message indicative of an SOC of a battery received at a regular interval while in a key-on state and driver torque demand is present, divert power from a load, and

generate torque of an electric machine at a speed to provide power equal to a propulsion demand and parasitic losses of the electric powertrain to diminish a change in battery power.

6. The vehicle of claim 5, wherein the controller is further configured to, upon reception of messages after the absence, output a command to restore the power to the load.

7. The vehicle of claim 5, wherein the controller is further configured to restrict power flow between the battery and the electric machine to a limit that is based on a predicted SOC to provide limited propulsive force.

8. The vehicle of claim 7, wherein the controller is further configured to, upon reception of messages after the absence, output a command to restore the power flow between the battery and electric machine.

9. The vehicle of claim 7, wherein restricting power flow between the battery and an electric machine by the controller includes diverting power from the load to the electric machine such that a change in power flow with the battery is minimized.

10. The vehicle of claim 7, wherein the predicted SOC of the battery is based on a bus voltage and bus current measured by a power inverter.