DC inverter having reduced switching loss and reduced voltage spikes

• US 10,011,178 B1
• Filed: 06/08/2017
• Issued: 07/03/2018
• Est. Priority Date: 06/08/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Xu, Zhuxian, Chen, Chingchi
• Primary Examiner(s): Luo, David S
• Application Number:
  US15/617,239
• Time in Patent Office: 390 Days
• Field of Search: 318139, 318 34
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• 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 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/084 using a control circuit common to several phases of a multi-phase system
• CPC Class Codes: H02M 1/15 using active elements
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H03K 17/08128 in composite switches
• CPC Class Codes: H03K 17/168 in composite switches
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

An electrified vehicle propulsion system uses current feedback to modify gate drive signals to suppress voltage spikes and increase switching efficiency. A DC link having a link capacitor and a link inductance is connected to first and second converters. A first converter bridge has a first phase leg with first upper and lower switching devices, each switching device having a respective gate loop. A second converter bridge has a second phase leg with second upper and lower switching devices, each switching device having a respective gate loop. A plurality of gate drivers provide gate drive signals to respective gate loops for turning the respective switching devices on and off. A plurality of gate coils are provided, wherein each gate coil is connected in series between a respective gate driver and a respective gate loop. Each gate coil is respectively inductively coupled to the link inductance.

Claims

1. An electrified vehicle propulsion system comprising:

a DC link having a link capacitor and a link inductance;

a first converter bridge with a first phase leg having first upper and lower switching devices, each switching device having a respective gate loop;

a second converter bridge with a second phase leg having second upper and lower switching devices, each switching device having a respective gate loop;

a plurality of gate drivers providing gate drive signals to respective gate loops for turning the respective switching devices on and off;

a plurality of gate coils, each gate coil connected in series between a respective gate driver and a respective gate loop and each respectively inductively coupled to the link inductance.

2. The system of claim 1 wherein the DC link comprises a busbar, and wherein each gate coil is directly magnetically coupled with the busbar.

3. The system of claim 1 wherein the DC link comprises a busbar, and wherein the system further comprises:

a sensing coil magnetically coupled to the busbar; and

a transformer having a primary winding connected to the sensing coil and having a plurality of secondary windings forming the gate coils.

4. The system of claim 1 further comprising a plurality of bypass paths, each bypass path connected between a respective gate drive and a respective gate loop, wherein each bypass path is activated to selectably bypass a respective gate coil except during respective transitions in a respective gate drive signal.

5. The system of claim 4 wherein the respective transitions correspond to turning off a respective switching device.

6. The system of claim 1 wherein the first converter bridge includes a plurality of phase legs, each phase leg having respective upper and lower switching devices, wherein each switching device has a respective gate coil.

7. The system of claim 6 wherein the second converter bridge comprises a variable voltage converter controlling a voltage on the DC link.

8. The system of claim 1 wherein:

the first converter bridge comprises a motor inverter including a plurality of phase legs, each phase leg having respective upper and lower switching devices, wherein each switching device has a respective gate coil; and

the second converter bridge comprises a generator inverter including a plurality of phase legs, each phase leg having respective upper and lower switching devices, wherein each switching device has a respective gate coil.

9. An electric drive inverter, comprising:

a DC link having a link inductance;

a plurality of phase legs, each having upper and lower switching devices, each device having a gate loop;

a plurality of gate drivers providing gate drive signals to respective gate loops; and

a plurality of gate coils, each gate coil connected in series between a respective gate driver and a respective gate loop and each respectively inductively coupled to the link inductance.

10. The inverter of claim 9 wherein the DC link comprises a busbar, and wherein each gate coil is directly magnetically coupled with the busbar.

11. The inverter of claim 9 wherein the DC link comprises a busbar, and wherein the inverter further comprises:

a sensing coil magnetically coupled to the busbar; and

a transformer having a primary winding connected to the sensing coil and having a plurality of secondary windings forming the gate coils.

12. The inverter of claim 9 further comprising a plurality of bypass paths, each bypass path connected between a respective gate drive and a respective gate loop, wherein each bypass path is activated to selectably bypass a respective gate coil except during respective transitions in a respective gate drive signal.

13. The inverter of claim 12 wherein the respective transitions correspond to turning off a respective switching device.

14. An electric vehicle drive comprising:

a DC power source;

a DC link having a link capacitor and a link inductance;

a variable voltage converter having upper and lower switching devices, each switching device having a respective gate loop;

a motor inverter with a plurality of phase legs each having upper and lower switching devices, each switching device having a respective gate loop;

a plurality of gate drivers providing gate drive signals to respective gate loops for turning the respective switching devices on and off;

a plurality of gate coils, each gate coil connected in series between a respective gate driver and a respective gate loop and each respectively inductively coupled to the link inductance.

15. The electric vehicle drive of claim 14 further comprising:

a generator inverter with a plurality of phase legs each having upper and lower switching devices, wherein each switching device has a respective gate loop, and wherein each respective gate loop is inductively coupled to the link inductance by a respective gate coil.

16. The electric vehicle drive of claim 14 wherein the DC link comprises a busbar, and wherein each gate coil is directly magnetically coupled with the busbar.

17. The electric vehicle drive of claim 14 wherein the DC link comprises a busbar, and wherein the electric vehicle drive further comprises:

a sensing coil magnetically coupled to the busbar; and

a transformer having a primary winding connected to the sensing coil and having a plurality of secondary windings forming the gate coils.

18. The electric vehicle drive of claim 14 further comprising a plurality of bypass paths, each bypass path connected between a respective gate drive and a respective gate loop, wherein each bypass path is activated to selectably bypass a respective gate coil except during respective transitions in a respective gate drive signal.

19. The electric vehicle drive of claim 18 wherein the respective transitions correspond to turning off a respective switching device.