VOLTAGE SOURCE CONVERTER AND METHOD OF CONTROLLING A VOLTAGE SOURCE CONVERTER

• US 20090080225A1
• Filed: 12/28/2005
• Published: 03/26/2009
• Est. Priority Date: 12/28/2005
• Status: Abandoned Application

• Current Assignee: ABB Research Ltd. (ABB Limited)
• Original Assignee: ABB Research Ltd. (ABB Limited)
• Inventors: Dijkhuizen, Frans
• Application Number:
  US12/159,618
• Publication Number:
  US 20090080225A1
• Time in Patent Office: Days
• US Class Current: 363/65
• CPC Class Codes: H02M 1/0074 Plural converter units whose inputs are connected in series
• 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 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02M 7/5395 by pulse-width modulation

Abstract

A voltage source converter for conversion between dc and ac voltage includes at least two serially connected phase legs. The outputs of the conversion stages form phase outputs to be connected to a phase of an alternating voltage network via a respective transformer. The configuration of the conversion stages reduces the requirements on the individual components of the voltage source converter.

Claims

1. A voltage source converter for conversion of dc voltage into ac voltage, and vice versa, the voltage source converter comprising:

at least two phase legs, each having a conversion stage, an output of which is adapted to form a phase output to be connected to a phase of an alternating voltage network via a transformer, wherein the phase legs of the converter are connected in series, wherein opposite ends of the series connection formed by an outer end of a respective outer phase leg of the series connection are configured to be connected to a respective pole conductor of a direct voltage network, and wherein each of said at least two phase legs comprises at least a further conversion stage, an output of which is connected to a further transformer.

2. The voltage source converter according to claim 1, wherein the conversion stages are connected in series in each phase leg.

3. The voltage source converter according to claim 1, wherein each power conversion stage comprises a half bridge power converter.

4. The voltage source converter according to claim 1, wherein each power conversion stage comprises a full bridge power converter.

5. The voltage source converter according to claim 1, wherein the transformers in each phase leg are connected in a cascade.

6. The voltage source converter according to claim 1, wherein the converters in each phase leg are connected to a first winding of single phase transformers in an open delta configuration.

7. The voltage source converter according to claim 6, wherein the second windings of the single phase transformers are connected in series to provide three phase outputs.

8. The voltage source converter according to claim 1, wherein each phase leg comprises three power conversion stages.

9. The voltage source converter according to claim 1, wherein the number of phase legs is three.

10. A method of controlling a voltage source converter for conversion of dc voltage into ac voltage, and vice versa, said voltage source converter comprising:

at least two phase legs, each having a conversion stage, an output of which is adapted to form a phase output to be connected to a phase of an alternating voltage network via a transformer, wherein the phase legs of the converter are connected in series, wherein opposite ends of the series connection formed by an outer end of a respective outer phase leg of the series connection are configured to be connected to a respective pole conductor of a direct voltage network, and wherein each of said at least two phase legs comprises at least a further conversion stage, an output of which is connected to a further transformer,

said method comprising;

controlling, for each phase leg, at least two converter stages, the output of which being connected to a further transformer.