Voltage source converter (VSC) with neutral-point-clamped (NPC) topology and method for operating such voltage source converter

Patent metadata

Field	Value
Publication number	US-9543855-B2
Application number	US-201213669058-A
Country	US
Kind code	B2
Filing date	Nov 5, 2012
Priority date	Nov 4, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A Voltage Source Converter (VSC) ( 10 ) with Neutral-Point-Clamped (NPC) topology with one or more phases, comprises an intermediate DC circuit having at least a first and a second capacitance connected in series between a positive terminal and a negative terminal, providing a central tap terminal between both capacitances, and at least one sub-circuit for generating one phase of an alternating voltage, each sub-circuit comprising an AC terminal for supplying a pulsed voltage; a circuit arrangement of the form of a conventional NPC converter, with a first series connection of at least two switches between said AC terminal and said positive terminal, a second series connection of at least two switches between said AC terminal said negative terminal, and switchable connections from said central tap terminal to the centers of both two-switch series connections; and additional first and second auxiliary switches assigned to said two-switch series connections.

First claim

The invention claimed is:

1. A Voltage Source Converter (VSC) with Neutral-Point-Clamped (NPC) topology with one or more phases, comprising: an intermediate DC circuit having four capacitances connected in series between a positive terminal and a negative terminal, providing a central tap terminal between the two center capacitances of said four capacitances connected in series, and at least one sub-circuit for generating one phase of an alternating voltage, each sub-circuit comprising:
an AC terminal for supplying a pulsed voltage;
a circuit arrangement of a form of a NPC converter, with:
a first series connection of at least four active switches between said AC terminal and said positive terminal, wherein each active switch has a diode connected in parallel;
a second series connection of at least four active switches between said AC terminal and said negative terminal, wherein each active switch has a diode connected in parallel;
a diode connected between each connection point between the capacitances of said four capacitances connected in series, and further connected to each connection point between the active switches of said first series connection of at least four active switches and second series connection of at least four active switches;
additional first and second auxiliary active switches connected in series between said AC terminal and said positive terminal, wherein the first auxiliary active switch is connected in parallel to two active switches of said first series connection of at least four active switches, and the second auxiliary active switch is connected in parallel to the other two active switches of said first series connection of at least four active switches; and
additional third and fourth auxiliary active switches connected in series between said AC terminal and said negative terminal, wherein the third auxiliary active switch is connected in parallel to two active switches of said second series connection of at least four active switches, and the fourth auxiliary active switch is connected in parallel to the other two active switches of said second series connection of at least four active switches.

2. A Voltage Source Converter (VSC) with Neutral-Point-Clamped (NPC) topology with one or more phases comprising: an intermediate DC circuit having six capacitances connected in series between a positive terminal and a negative terminal, providing a central tap terminal between two center capacitances of said six capacitances connected in series, and at least one sub-circuit for generating one phase of an alternating voltage, each sub-circuit comprising:
an AC terminal for supplying a pulsed voltage;
a circuit arrangement of a form of a NPC converter, with:
first series connection of at least six active switches between said AC terminal and said positive terminal, wherein each active switch has a diode connected in parallel;
a second series connection of at least six active switches between said AC terminal and said negative terminal, wherein each active switch has a diode connected in parallel;
a diode connected between each connection point between the capacitances of said six capacitances connected in series, and further connected to each connection point between the active switches of said first series connection of at least six active switches and second series connection of at least six active switches;
additional first, second and third auxiliary active switches connected in series between said AC terminal and said positive terminal, wherein the first auxiliary active switch is connected in parallel to two active switches of said first series connection of at least six active switches, the second auxiliary active switch is connected in parallel to two other active switches of said first series connection of at least six active switches, and the third auxiliary active switch is connected in parallel to further two other active switches of said first series connection of at least six active switches; and
additional fourth, fifth and sixth auxiliary active switches connected in series between said AC terminal and said negative terminal, wherein the fourth auxiliary active switch is connected in parallel to two active switches of said second series connection of at least six active switches, the fifth auxiliary active switch is connected in parallel to two other active switches of said second series connection of at least six active switches, and the sixth auxiliary active switch is connected in parallel to further two other active switches of said second series connection of at least six active switches.

Assignees

• Alstom Technology Ltd
• General Electric Technology Gmbh

Inventors

• Soeiro Thiago Batista
• Kolar Johann Walter
• Ranstad Per
• Linner Jörgen

Classifications

• H02M2001/0054

  Electricity · mapped topic

• H02M7/537 Primary

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• Y02B70/1491

  Cross-Sectional Technologies · mapped topic

• H02M7/487 Primary

  Neutral point clamped inverters · CPC title

• H02M1/0054

  Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035) · CPC title