Modular stacked dc architecture traction system and method of making same

Patent metadata

Field	Value
Publication number	US-2017133969-A1
Application number	US-201715415195-A
Country	US
Kind code	A1
Filing date	Jan 25, 2017
Priority date	Nov 30, 2011
Publication date	May 11, 2017
Grant date	—

Abstract

A modular stacked DC architecture for traction system includes a propulsion system includes an electric drive, a direct current (DC) link electrically coupled to the electric drive, and a first DC-DC converter coupled to the DC link. A first energy storage device (ESD) is electrically coupled to the first DC-DC converter, and a second DC-DC converter is coupled to the DC link and to the first DC-DC converter. The system also includes a second energy storage device electrically coupled to the second DC-DC converter and a controller coupled to the first and second DC-DC converters and configured to control a transfer of energy between the first ESD and the DC link via the first and second DC-DC converters.

First claim

What is claimed is:

1 . A propulsion system comprising:
an electric drive; a direct current (DC) link comprising a first bus and a second bus coupled to the electric drive; a first DC-DC converter coupled to the first bus of the DC link, the first DC-DC converter comprising a first plurality of switch legs; a second DC-DC converter coupled to the second bus of the DC link and the first DC-DC converter, the second DC-DC converter comprising a second plurality of switch legs; a first energy storage device (ESD) coupled to the first DC-DC converter; a second ESD coupled to the second DC-DC converter; and a controller configured to:
selectively transfer energy from one or both of the first ESD and the second ESD to the electric drive by controlling a first plurality of switches in the first DC-DC converter and a second plurality of switches in the second DC-DC converter; and
selectively transfer energy from the electric drive to charge one or both of the first ESD and the second ESD by controlling a third plurality of switches in the first DC-DC converter and a fourth plurality of switches in the second DC-DC converter.

2 . The propulsion system of claim 1 wherein the first plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

3 . The propulsion system of claim 1 wherein the second plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

4 . The propulsion system of claim 1 wherein the third plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

5 . The propulsion system of claim 1 wherein the fourth plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

6 . The propulsion system of claim 1 wherein the controller is further configured to control a duty cycle of each of the plurality of switches.

7 . The propulsion system of claim 1 wherein the first DC-DC converter and the second DC-DC converter are bi-directional.

8 . The propulsion system of claim 1 wherein a first leg of the first DC-DC converter, a first leg of the second DC-DC converter, and the electric drive form an H-bridge.

9 . The propulsion system of claim 1 further comprising a third DC-DC converter coupled between the electric drive and the first and second DC-DC converters.

10 . A vehicle comprising:
an electric drive comprising an inverter coupled to a traction motor; a direct current (DC) link comprising a first bus and a second bus coupled to the electric drive; a first DC-DC converter coupled to the first bus of the DC link, the first DC-DC converter comprising a first plurality of switch legs; a second DC-DC converter coupled to the second bus of the DC link and the first DC-DC converter, the second DC-DC converter comprising a second plurality of switch legs; a first energy storage device (ESD) coupled to the first DC-DC converter; a second ESD coupled to the second DC-DC converter; and a controller configured to:
selectively transfer energy from one or both of the first ESD and the second ESD to the electric drive by controlling a first plurality of switches in the first DC-DC converter and a second plurality of switches in the second DC-DC converter; and
selectively transfer energy from the electric drive to charge one or both of the first ESD and the second ESD by controlling a third plurality of switches in the first DC-DC converter and a fourth plurality of switches in the second DC-DC converter.

11 . The vehicle of claim 10 wherein the first plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

12 . The vehicle of claim 10 wherein the second plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

13 . The vehicle of claim 10 wherein the third plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

14 . The vehicle of claim 10 wherein the fourth plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

15 . The vehicle of claim 10 further comprising a third DC-DC converter coupled between the electric drive and the first and second DC-DC converters.

16 . A method of operating a propulsion system comprising:
coupling an electric drive to a direct current (DC) link, the DC link comprising a first bus and a second bus; coupling a first DC-DC converter to the first bus, the first DC-DC converter comprising a first plurality of switch legs; coupling a second DC-DC converter to the second bus and the first DC-DC converter, the second DC-DC converter comprising a second plurality of switch legs; coupling a first energy storage device (ESD) to the first DC-DC converter; coupling a second ESD to the second DC-DC converter; and configuring a controller to:
selectively transfer energy from one or both of the first ESD and the second ESD to the electric drive by controlling a first plurality of switches in the first DC-DC converter and a second plurality of switches in the second DC-DC converter; and
selectively transfer energy from the electric drive to charge one or both of the first ESD and the second ESD by controlling a third plurality of switches in the first DC-DC converter and a fourth plurality of switches in the second DC-DC converter.

17 . The method of claim 16 wherein the first plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

18 . The method of claim 16 wherein the second plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

19 . The method of claim 16 wherein the third plurality of switches on the first DC-DC converter comprises a first switch from a first leg of the first DC-DC converter and a second switch from a second leg of the first DC-DC converter.

20 . The method of claim 16 wherein the fourth plurality of switches on the second DC-DC converter comprises a first switch from a first leg of the second DC-DC converter and a second switch from a second leg of the second DC-DC converter.

Assignees

• Gen Electric

Inventors

• Kanakasabai Viswanathan
• Sen Bhaskar

Classifications

• B60L2240/54

  related to batteries · CPC title

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02P27/14

  with three or more levels of voltage · CPC title

• B60L50/40

  using propulsion power supplied by capacitors · CPC title

• B60L2210/10

  DC to DC converters · CPC title