Variable resistance power switch feedback

Patent metadata

Field	Value
Publication number	US-10432186-B2
Application number	US-201715812175-A
Country	US
Kind code	B2
Filing date	Nov 14, 2017
Priority date	Nov 14, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A vehicle powertrain has a power inverter that includes a load switch with a main emitter and a current mirror emitter, a variable resistor coupled between the current mirror emitter and the main emitter, and a controller. The controller may be configured to adjust a gate voltage based on a voltage across the variable resistor, and responsive to the gate voltage exceeding a Miller plateau gate voltage, increase a variable resistor resistance such that feedback increases as the load switch saturates.

First claim

What is claimed is:

1. A vehicle powertrain comprising:
a power inverter including
a load switch with main and current mirror emitters, and
a variable resistor coupled between the main and current mirror emitters; and

a controller configured to
adjust a gate voltage based on a voltage across the variable resistor, and
responsive to the gate voltage exceeding a Miller plateau gate voltage, increase a resistance of the variable resistor such that a feedback voltage increases as the load switch saturates.

2. The vehicle powertrain of claim 1 , wherein the variable resistor includes a first resistor coupled in parallel with a second resistor that is selectable via a solid-state switch, wherein a resistance of the first resistor is greater than the second resistor.

3. The vehicle powertrain of claim 1 , wherein the variable resistor is a solid-state variable resistor coupled in parallel with a sense resistor.

4. The vehicle powertrain of claim 3 , wherein the controller is further configured to select a resistance of the solid-state variable resistor based on an ambient temperature.

5. The vehicle powertrain of claim 3 , wherein the controller is further configured to select a resistance of the solid-state variable resistor based on a temperature of the load switch.

6. The vehicle powertrain of claim 1 , wherein the load switch is an Insulated Gate :Bipolar Junction Transistors (IGBTs).

7. A vehicle powertrain comprising:
a load switch monolithically integrated with a mirror switch;
a variable resistor coupled between a mirror switch emitter and a reference point; and
a controller configured to
adjust a gate voltage based on a voltage across the variable resistor, and
responsive to the gate voltage exceeding a Miller plateau gate voltage, increase a resistance of the variable resistor such that a feedback voltage increases as the load switch saturates.

8. The vehicle powertrain of claim 7 , Wherein the reference point is a main emitter and the load switch and the mirror switch are insulated Gate Bipolar Junction Transistors (IGBTs).

9. The vehicle powertrain of claim 7 , wherein the variable resistor includes a first resistor coupled in parallel with a second resistor that is selectable via a solid-state switch, wherein a resistance of the first resistor is greater than the second resistor.

10. The vehicle powertrain of claim 7 , wherein the load switch is configured to flow current into an inductor of a variable voltage converter.

11. The vehicle powertrain of claim 7 , wherein the load switch is in a power inverter and configured to flow current into a phase winding of an electric machine.

12. The vehicle powertrain of claim 7 , wherein the variable resistor is a solid-state variable resistor coupled in parallel with a sense resistor.

13. The vehicle powertrain of claim 12 , wherein the controller is further configured to select a resistance of the solid-state variable resistor based on an ambient temperature.

14. The vehicle powertrain of claim 12 wherein the controller is further configured to select a resistance of the solid-state variable resistor based on a temperature of the load switch.

15. A method of controlling a power switch in a vehicle powertrain comprising:
setting a resistance of a variable resistor, coupled between a current mirror emitter and reference point, to a first value while a gate voltage of the power switch is below a turn-on threshold;
applying a charge to the gate to increase the gate voltage; and
responsive to the gate voltage exceeding a Miller plateau gate voltage, increasing the resistance of the variable resistor.

16. The method of claim 15 , wherein the variable resistor includes a first resistor coupled in parallel with a second resistor that is selectable via a solid-state switch, and changing the resistance of the variable resistor is disconnecting the second resistor.

17. The method of claim 15 , wherein the resistance is set based on a temperature of the power switch.

18. The method of claim 15 , wherein the resistance is set based on a power demand of the vehicle powertrain.

Assignees

• Ford Global Tech Llc

Inventors

• Yang Shuitao
• Zhou Yan
• Chen Lihua
• Xu Fan
• Alam Mohammed Khorshed
• Ge Baoming

Classifications

• B60Y2200/92

  Hybrid vehicles · CPC title

• H03K17/0412

  by measures taken in the control circuit · CPC title

• Y10S903/904

  Component specially adapted for hev · CPC title

• H03K17/0828 Primary

  in composite switches · CPC title

• B60R16/005

  Electro-mechanical devices, e.g. switched (electric switches in general H01H) · CPC title