Recuperative brake on a vehicle

Patent metadata

Field	Value
Publication number	US-2017305299-A1
Application number	US-201715491567-A
Country	US
Kind code	A1
Filing date	Apr 19, 2017
Priority date	Apr 20, 2016
Publication date	Oct 26, 2017
Grant date	—

Abstract

The present invention relates to a method for recuperation based braking of a vehicle in which electrical energy generated during a braking process is decreased by operating at lest one second electric machine of the vehicle in a zero slip mode in order to prevent overcharging of a traction battery of the vehicle.

First claim

What is claimed is:

1 . A method for recuperation-based braking of a vehicle, comprising:
generating electrical energy with a first electric machine of the vehicle during a braking process; operating with the electrical energy generated by the first electric machine a second electric machine in a zero slip mode in which a rotary field of a stator of the second electric machine synchronously follows a movement of a rotor of the second electric machine, so that no-load losses of the second electric machine are used to decrease the electrical energy generated by the first electric machine to thereby prevent overcharging of a traction battery of the vehicle.

2 . A method for recuperation-based braking of a vehicle, comprising:
generating electrical energy with a first electric machine of the vehicle during a braking process; as a function of an actual state of charge of a traction battery of the vehicle either operating with the electrical energy generated by the first electric machine a second electric machine in a zero slip mode in which a rotary field of a stator of the second electric machine synchronously follows a movement of a rotor of the second electric machine, so that no-load losses of the second electric machine are used to decrease the electrical energy generated by the first electric machine to thereby prevent overcharging of a traction battery of the vehicle, or transferring the electrical energy to the traction battery of the vehicle.

3 . The method of claim 1 , further comprising prior to the decreasing step transferring the electrical energy to a buffer storage.

4 . The method of claim 3 , wherein the buffer storage is configured as a part of the traction battery of the vehicle, said method further comprising dynamically discharging the buffer storage by operating the second electric machine of the vehicle in the zero slip mode when the vehicle is operated in a free mode.

5 . The method of claim 3 , wherein the second electric machine corresponds to the first electric machine.

6 . The method of claim 1 , wherein the first electric machine is assigned to a first one of at least two electrically driven axles of the vehicle, and the second electric machine is assigned to a second one of the at least two electrically driven axles of the vehicle.

7 . The method of claim 6 , wherein the electrical energy generated by the first electric machine is directly decreased by the second electric machine.

8 . The method of claim 6 , wherein an amount of the electrical energy generated by the first electric machine corresponds exactly to an amount of electrical energy that can subsequently be decreased by the second electric machine.

9 . A vehicle comprising:
a first electric machine configured to generate electrical energy during a recuperation-supported braking process of the vehicle; a second electric machine; and a control device, said control device being configured, as a function of a state of charge of a traction battery of the vehicle, to operate with the electrical energy generated by the first electric machine the second electric machine in a zero slip mode in which a rotary field of a stator of the second electric machine synchronously follows a movement of a rotor of the second electric machine, so that no-load losses of the second electric machine are used to decrease the electrical energy generated by the first electric machine to thereby prevent overcharging of a traction battery of the vehicle.

Assignees

• Audi Ag

Inventors

• Karl Bernhard
• Feldmann Uwe
• Winkelmeyr Felix
• Daschner René
• Heckel Thomas

Classifications

• B60L2220/42

  with use of more than one motor · CPC title

• B60L2240/421

  Speed · CPC title

• B60T8/17

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• B60L2240/54

  related to batteries · CPC title

• B60W30/00

  Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units · CPC title