DC-to-DC converter and electric motor drive system using the same

• US 7,606,053 B2
• Filed: 04/06/2006
• Issued: 10/20/2009
• Est. Priority Date: 04/06/2006
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Chen, Chingchi, Degner, Michael, Sankaran, Venkateswa
• Primary Examiner(s): Han; Jessica
• Assistant Examiner(s): PHAM, EMILY P
• Application Number:
  US11/278,867
• Publication Number:
  US 20070236965A1
• Time in Patent Office: 1,293 Days
• Field of Search: 363/132, 363/17, 323/225, 323/259, 323/282, 323/284, 323/344, 323/351, 180/65.1, 180/65.31
• US Class Current: 363/132
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/0093 wherein the output is created by adding a regulated voltage to or subtracting it from an unregulated input
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A DC-to-DC converter is provided and generally configured for implementation with an electric motor drive system. In at least one embodiment, the DC-to-DC converter includes first and second capacitors, an inductor, and first and second switching devices. The DC-to-DC converter is bi-directional to facilitate voltage transfer therethrough. In at least another embodiment, the electric motor drive system comprises an energy storage device, a drive unit, an electric motor and a bi-directional DC-to-DC converter. The energy storage device includes a positive and a negative terminal. The drive unit includes a first and second terminal. The electric motor is in electrical communication with the drive unit.

Claims

1. A DC-to-DC converter comprising:

a first capacitor having a first and second terminal and being rated to a first voltage rating;

a second capacitor having a first and second terminal;

an inductor having a first and second terminal, wherein the first terminal of the inductor is coupled to both the first terminal of the second capacitor and the second terminal of the first capacitor to form a first node;

a first switching device having a first and second terminal and configured to electrically couple the first and second terminals of the first switching device in response to a first control signal, wherein the first terminal of the first switching device is coupled to the first terminal of the first capacitor to form a second node; and

a second switching device having a first and second terminal and configured to electrically couple the first and second terminals of the second switching device in response to a second control signal, wherein;

the first terminal of the second switching device is coupled to the second terminal of the first switching device and the second terminal of the inductor to form a third node,

the second terminal of the second switching device is coupled to the second terminal of the second capacitor to form a fourth node,

the DC-to-DC converter is configured to facilitate bi-directional voltage transfer therethrough, and

the first voltage rating of the first capacitor is substantially similar to a voltage between the first and second nodes.

2. The DC-to-DC converter of claim 1 wherein the first and second capacitors are polarized capacitors, the first terminal of each of the first and second capacitors corresponds to a positive lead, and the second terminal of each of the first and second capacitors corresponds to a negative lead.

3. The DC-to-DC converter of claim 1 wherein each of the first and second switching devices are Insulated Gate Bipolar Transistors having a collector region coupled to the first terminal, an emitter region coupled to the second terminal and a gate region coupled to a control unit and wherein a control unit generates and the gate region receives at least one of the first and second control signals.

4. The DC-to-DC converter of claim 1 further comprising:

a first diode having a positive terminal coupled to the third node and a negative terminal coupled to the second node; and

a second diode having a positive terminal coupled to the fourth node and a negative terminal coupled to the third node.

5. The DC-to-DC converter of claim 1 further comprising a diode having a positive terminal coupled to the first node and a negative terminal coupled to the second node.

6. The DC-to-DC converter of claim 1 further comprising a diode having a positive terminal coupled to the fourth node and a negative terminal coupled to the first node.

7. The DC-to-DC converter of claim 1 further comprising a third capacitor having a first terminal coupled to the second node and a second terminal coupled to the fourth node.

8. The system of claim 1 wherein the second capacitor is rated to a second voltage rating that is substantially similar to a voltage between the first and the fourth nodes.

9. An electric motor drive system comprising:

an energy storage device having a positive and a negative terminal;

a drive unit having a first and second terminal;

an electric motor in electronic communication with the drive unit; and

a bi-directional DC-to-DC converter comprising;

a first capacitor having a first and second terminal;

a second capacitor having a first and second terminal and being rated to a first voltage rating;

an inductor having a first and second terminal, wherein the first terminal of the inductor is coupled to both the first terminal of the second capacitor and the second terminal of the first capacitor to form a first node;

a first switching device having a first and second terminal and configured to electrically couple the first and second terminals of the first switching device in response to a first control signal, wherein the first terminal of the first switching device is coupled to the first terminal of the first capacitor to form a second node; and

a second switching device having a first and second terminal and configured to electrically couple the first and second terminals of the second switching device in response to a second control signal, wherein;

the first terminal of the second switching device is coupled to the second terminal of the first switching device and the second terminal of the inductor to form a third node, and

the second terminal of the second switching device is coupled to the second terminal of the second capacitor to form a fourth node, and

the first voltage rating of the second capacitor is substantially similar to a voltage between the first and fourth nodes,

the positive terminal of the energy storage device is coupled to the first node and the negative terminal of the energy storage device is coupled to the fourth node, and the first and second terminals of the drive unit are coupled to the second and fourth nodes, respectively.

10. The system of claim 9 wherein the first capacitor is rated to a second voltage rating that is substantially similar to a voltage between the first and the second nodes.

11. The system of claim 9 further comprising a control circuit for generating the first and second control signals such that an input voltage corresponding to the energy storage device is stepped up and outputted to the drive unit.

12. The system of claim 9 further comprising a control circuit for generating the first and second control signals such that regenerative voltage generated by the electric motor is stepped down and outputted to the energy storage device.

13. The system of claim 9 further comprising a first terminal voltage configured for placement between the first and second nodes, wherein a first voltage rating of the first capacitor is equal to the first terminal voltage.

14. The system of claim 13 further comprising a second terminal voltage configured for placement between the first and fourth nodes, wherein a second voltage rating of the second capacitor is equal to the second terminal voltage.

15. The system of claim 9 wherein each of the first and second switching devices are Insulated Gate Bipolar Transistors having a collector region coupled to the first terminal, an emitter region coupled to the second terminal and a gate region coupled to a control unit, the control unit generating and the gate region receiving at least one of the first and second control signals.

16. The system of claim 9 further comprising:

a first diode having a positive terminal coupled to the third node and a negative terminal coupled to the second node; and

a second diode having a positive terminal coupled to the fourth node and a negative terminal coupled to the third node.

17. The system of claim 9 further comprising a diode having a positive terminal coupled to the first node and a negative terminal coupled to the second node.

18. The system of claim 9 further comprising a third capacitor having a first terminal coupled to the second node and a second terminal coupled to the fourth node.

19. An electric motor drive system comprising:

an energy storage device having a positive and a negative terminal;

a drive unit having a first and second terminal;

an electric motor in electronic communication with the drive unit; and

a bi-directional DC-to-DC converter comprising;

a first capacitor having a first and second terminal and being rated to a first voltage rating;

a second capacitor having a first and second terminal;

an inductor having a first and second terminal, wherein the first terminal of the inductor is coupled to both the first terminal of the second capacitor and the second terminal of the first capacitor to form a first node;

a first switching device having a first and second terminal and configured to electrically couple the first and second terminals of the first switching device in response to a first control signal, wherein the first terminal of the first switching device is coupled to the first terminal of the first capacitor to form a second node; and

a second switching device having a first and second terminal and configured to electrically couple the first and second terminals of the second switching device in response to a second control signal, wherein;

the first terminal of the second switching device is coupled to the second terminal of the first switching device and the second terminal of the inductor to form a third node,

the second terminal of the second switching device is coupled to the second terminal of the second capacitor to form a fourth node, and

the first voltage rating of the first capacitor is substantially similar to the voltage between the first and second nodes,

wherein the positive terminal of the energy storage device is coupled to the second node and the negative terminal of the energy storage device is coupled to the first node, and the first and second terminals of the drive unit are coupled to the second and fourth nodes, respectively.

20. The system of claim 19 further comprising a first terminal voltage configured for placement between the first and second nodes and a second terminal voltage configured for placement between the first and fourth nodes, wherein a first voltage rating of the first capacitor is equal to the first terminal voltage and a second voltage rating of the second capacitor is equal to the second terminal voltage.

21. The system of claim 19 wherein the second capacitor is rated to a second voltage rating that is substantially similar to a voltage between the first and the second nodes.