DC/DC converter

• US 9,461,538 B2
• Filed: 09/23/2013
• Issued: 10/04/2016
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited (Hitachi, Ltd.)
• Original Assignee: ABB Technology Limited (ABB Limited)
• Inventors: Alves, Roberto, Srivastava, Kailash, Lazarczyk, Michal
• Primary Examiner(s): Dole, Timothy J
• Assistant Examiner(s): JAMALI, ISHRAT F
• Application Number:
  US15/023,895
• Publication Number:
  US 20160248321A1
• Time in Patent Office: 1,107 Days
• US Class Current: 1/1
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• CPC Class Codes: H02M 1/4266 using passive elements
• CPC Class Codes: H02M 3/10 using discharge tubes with control electrode or semiconductor devices with control electrode H02M3/07 takes precedence
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/22 with intermediate conversion into ac
• CPC Class Codes: H02M 3/24 by static converters
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02M 7/483 Converters with outputs that each can have more than two voltages levels
• CPC Class Codes: Y02E 60/60 Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Abstract

It is presented a DC/DC converter for converting power between a first DC connection comprising a first positive terminal and a first negative terminal, and a second DC connection comprising a second positive terminal and a second negative terminal. The DC/DC converter comprises: a first multilevel converter and a second multilevel converter connected serially between the first positive terminal and the first negative terminal, wherein the second positive terminal is connected to a point between the first multilevel converter and the second multilevel converter; and a first filter connected between an AC terminal of the first multilevel converter and an AC terminal of the second multilevel converter, wherein the first filter comprises a capacitor and an inductor.

Claims

1. A DC/DC converter for converting power between a first DC connection comprising a first positive terminal and a first negative terminal, and a second DC connection comprising a second positive terminal and a second negative terminal, the DC/DC converter comprising:

a first multilevel converter and a second multilevel converter connected serially between the first positive terminal and the first negative terminal, wherein the second positive terminal is connected to a point between the first multilevel converter and the second multilevel converter;

where each converter has n phases, where n is a number of two or more, and for each phase there is an upper converter arm and a lower converter arm, each comprising a number of serially connected converter cells, where there are inductors between the upper and lower converter arms and respective AC terminals are provided between the inductors of each phase, and

a first filter connected between an AC terminal of the first multilevel converter and an AC terminal of the second multilevel converter, wherein the first filter comprises a capacitor and an inductor.

2. The DC/DC converter according to claim 1, wherein the first negative terminal is connected to ground and the second negative terminal is connected to ground.

3. The DC/DC converter according to claim 2, wherein for the first filter and the second filter when present, the inductor is a reactor component.

4. The DC/DC converter according to claim 2, wherein for the first filter and the second filter when present, the inductor is implemented by a parasitic inductance.

5. The DC/DC converter according to claim 2, wherein the first filter and the second filter when present, comprises a resistor.

6. The DC/DC converter according to claim 1, further comprising:

a third multilevel converter and a fourth multilevel converter connected serially between the second multilevel converter and the first negative terminal, wherein the second negative terminal is connected to a point between the third multilevel converter and the fourth multilevel converter; and

a second filter connected between an AC terminal of the third multilevel converter and an AC terminal of the fourth multilevel converter, wherein the second filter comprises a capacitor and an inductor.

7. The DC/DC converter according to claim 6, wherein for the first filter and the second filter when present, the inductor is a reactor component.

8. The DC/DC converter according to claim 6, wherein for the first filter and the second filter when present, the inductor is implemented by a parasitic inductance.

9. The DC/DC converter according to claim 6, wherein the first filter and the second filter when present, comprises a resistor.

10. The DC/DC converter according to claim 1, wherein for the first filter and the second filter when present, the inductor is a reactor component.

11. The DC/DC converter according to claim 10, wherein for the first filter and the second filter when present, the inductor is implemented by a parasitic inductance.

12. The DC/DC converter according to claim 10, wherein the first filter and the second filter when present, comprises a resistor.

13. The DC/DC converter according to claim 1, wherein for the first filter and the second filter when present, the inductor is implemented by a parasitic inductance.

14. The DC/DC converter according to claim 13, wherein the first filter and the second filter when present, comprises a resistor.

15. The DC/DC converter according to claim 1, wherein the first filter and the second filter when present, comprises a resistor.

16. The DC/DC converter according to claim 1, wherein a main resonance frequency of the first filter and the second filter, when present, is less than the frequency provided on the AC terminals of the multilevel converters.

17. The DC/DC converter according to claim 1, wherein an impedance of the first filter and the second filter, when present, is at a minimum at its respective main resonance frequency.

18. The DC/DC converter according to claim 1, wherein the capacitor of the first filter and the second filter when present, blocks DC through the respective filter.

19. The DC/DC converter according to claim 1, wherein each multilevel converter comprises a plurality of converter cells.

20. The DC/DC converter according to claim 19, wherein each one of the converter cells comprises at least one switching element and at least one energy storage element.