Variable carrier switching frequency control of variable voltage converter

Patent metadata

Field	Value
Publication number	US-10239407-B2
Application number	US-201615005671-A
Country	US
Kind code	B2
Filing date	Jan 25, 2016
Priority date	Jan 25, 2016
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A controller is configured to select a rate of change direction of an output voltage of a variable voltage converter (VVC) based on a direction of current flow associated with a capacitor of the VVC, and to adjust a magnitude of the rate of change direction based on directions of current flow associated with the capacitor and an electric machine coupled to the VVC.

First claim

What is claimed is:

1. An electric vehicle power conversion system comprising:
a variable voltage converter, including a capacitor, configured to generate an output voltage for a load; and
a controller configured to select a rate of change direction for the output voltage based on a current flow direction of the capacitor, and to adjust a magnitude of the rate of change direction based on the current flow direction and a load current flow direction.

2. The system of claim 1 , wherein the rate of change direction is positive in response to the current flow direction being into the capacitor.

3. The system of claim 2 , wherein adjusting the magnitude includes decreasing the magnitude in response to the current flow direction and load current flow direction being same.

4. The system of claim 2 , wherein adjusting the magnitude includes increasing the magnitude in response to the current flow direction and load current flow direction being opposite.

5. The system of claim 1 , wherein the rate of change direction is negative in response to the current flow direction being from the capacitor.

6. The system of claim 5 , wherein adjusting the magnitude includes decreasing the magnitude in response to the current flow direction and load current direction being same.

7. The system of claim 5 , wherein adjusting the magnitude includes decreasing the magnitude in response to the current flow direction and load current direction being opposite.

8. A vehicle comprising:
an electric machine;
a variable voltage converter, including a capacitor, configured to produce a voltage for the electric machine; and
a controller configured to select a positive rate of change direction for the voltage in response to a current flow direction being into the capacitor, and to decrease a magnitude of the rate of change direction in response to the current flow direction and an electric machine current flow direction being same.

9. The vehicle of claim 8 , wherein the controller is further configured to select a negative rate of change direction for the voltage in response to the current flow direction being from the capacitor.

10. The vehicle of claim 8 , wherein the controller is further configured to increase the magnitude in response to the current flow direction and electric machine current flow direction being opposite.

11. The vehicle of claim 8 , wherein the controller is further configured to decrease the magnitude using a filter or voltage schedule look-up table.

12. A controller-implemented method for operating an electric powertrain DC-DC converter coupled with an electric machine comprising:
selecting a rate of change direction of an output voltage of the converter based on a current flow direction of a capacitor of the converter; and
adjusting a magnitude of the rate of change direction based on the current flow direction of the capacitor and a current flow direction of the electric machine.

13. The method of claim 12 , wherein the rate of change direction is positive in response to the current flow direction being into the capacitor.

14. The method of claim 12 , wherein the rate of change direction is negative in response to the current flow direction being from the capacitor.

15. The method of claim 12 , wherein the adjusting includes increasing the magnitude in response to the current flow directions being opposite.

16. The method of claim 12 , wherein the adjusting includes decreasing the magnitude in response to the current flow directions being same.

17. The method of claim 12 , wherein the adjusting is further based on a magnitude of current flow to the capacitor and a magnitude of current flow to the electric machine.

Assignees

• Ford Global Tech Llc

Inventors

• Yu Lan
• Degner Michael W

Classifications

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title

• B60L2240/547

  Voltage · CPC title

• B60L50/15

  with additional electric power supply (with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61) · CPC title

• Y02T90/14

  Plug-in electric vehicles · CPC title