Multilevel converter

Patent metadata

Field	Value
Publication number	US-2015280605-A1
Application number	US-201414229074-A
Country	US
Kind code	A1
Filing date	Mar 28, 2014
Priority date	Mar 28, 2014
Publication date	Oct 1, 2015
Grant date	—

Abstract

A power converter is presented. The power converter includes at least one leg, the at least one leg includes a first string, where the first string includes a plurality of diodes, a first connecting node, and a second connecting node, and where the first string is operatively coupled across a first bus and a second bus. Furthermore, the at least one leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes a plurality of switching units.

First claim

1 . A power converter, comprising:
at least one leg, comprising:
a first string comprising a plurality of diodes, a first connecting node, and a second connecting node, wherein the first string is operatively coupled across a first bus and a second bus; and
a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string comprises a plurality of switching units.

2 . The power converter of claim 1 , wherein the plurality of switching units comprises a plurality of fully controllable semiconductor switches and at least one energy storage device.

3 . The power converter of claim 1 , wherein the plurality of switching units comprises a half bridge converter, a full bridge converter or combinations thereof.

4 . The power converter of claim 1 , wherein the first bus comprises a positive direct current bus and the second bus comprises a negative direct current bus.

5 . The power converter of claim 1 , wherein the first string comprises a first branch and a second branch, and wherein the second branch is operatively coupled to the first branch via a third connecting node.

6 . The power converter of claim 5 , wherein the third connecting node is operatively coupled to a third bus.

7 . The power converter of claim 6 , wherein the third bus comprises a direct current bus, a floating bus, a grounded bus or high impedance grounded bus.

8 . The power converter of claim 1 , wherein the second string comprises a first portion and a second portion.

9 . The power converter of claim 8 , wherein the first and second portions of the second string are operatively coupled to a fourth bus.

10 . The power converter of claim 9 , wherein the fourth bus comprises an alternating current phase.

11 . The power converter of claim 9 , wherein the controller operates each of the one or more legs in a positive state or a negative state or a zero state.

12 . The power converter of claim 9 , wherein in the positive state, the first portion and the second portion are connected between the first bus and the third bus, in the negative state, the first portion and the second portion are connected between the third bus and the second bus and in the zero state, the first portion and the second portion both are connected to the third bus.

13 . A system for power conversion, comprising:
a power source; a load; a first power converter, comprising:
one or more legs, wherein each of the one or more legs comprises:
a first string comprising a plurality of diodes, a first connecting node, a second connecting node, and a third connecting node, wherein the first string is operatively coupled across a first bus and a second bus;
a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string comprises a plurality of switching units; and

a controller configured to control switching of the plurality of switching units.

14 . The system of claim 13 , wherein the power source comprises a grid and the load comprises an electric drive or a subsea load.

15 . The system of claim 13 , wherein the controller is further configured to regulate energy stored in the second string during a line cycle.

16 . The system of claim 13 , wherein the plurality of switching units comprise a half bridge converter, a full bridge converter, or a combination thereof.

17 . The system of claim 13 , wherein the second string comprises a first portion and a second portion.

18 . The power converter of claim 17 , wherein the first and second portions of the second string are operatively coupled to an alternating current phase.

19 . A system for power conversion, comprising:
a power source; a load; a first power converter, comprising:
one or more legs, wherein each of the one or more legs comprises:
a first string operatively coupled between a first bus and a second bus, wherein the first string comprises a plurality of diodes, a first connecting node, a second connecting node, and a third connecting node, and wherein the third connecting nodes of the one or more legs are operatively coupled to each other;
a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string comprises a plurality of switching units; and

a controller configured to control switching of the plurality of switching units.

20 . The system of claim 19 , wherein the third connecting nodes of the one or more legs are operatively coupled to a third bus.

Assignees

• Gen Electric

Inventors

• Zhang Di
• Lai Rixin
• Garces Luis Jose

Classifications

• H02M7/219

  in a bridge configuration · CPC title

• H02M7/487

  Neutral point clamped inverters · CPC title

• H02M7/217 Primary

  using semiconductor devices only · CPC title

• H02M7/4835

  comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage · CPC title

• H02M1/0095 Primary

  Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck · CPC title