Medium voltage DC collection system with power electronics

Patent metadata

Field	Value
Publication number	US-9525284-B2
Application number	US-201314038842-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Oct 1, 2012
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A power generation system includes at least one generator that generates a medium voltage direct current that has a positive DC voltage output and a negative DC voltage output. The system also provides a medium voltage DC (MVDC) cable system with a positive pole cable and a negative pole cable, wherein the positive pole cable is connected to the positive DC voltage output and the negative pole cable is connected to the negative DC voltage output. A substation is connected to the MVDC cable system and includes at least one DC/DC step-up converter to step-up the medium voltage direct current to a high voltage direct current.

First claim

What is claimed is:

1. A power generation system, comprising:
at least one generator that generates a medium voltage direct current that has a positive DC voltage output and a negative DC voltage output;
each said at least one generator comprising a multi-phase generator associated with a pair of AC/DC rectifiers, each said AC/DC rectifier having a positive DC output and a negative DC output, wherein said negative output from a first AC/DC rectifier is connected to said positive output from a second AC/DC rectifier said positive output from said first AC/DC rectifier defining said positive DC voltage output and said negative output from said second AC/DC rectifier defining said negative DC voltage output;
a medium voltage DC (MVDC) cable system comprising:
a positive pole cable and a negative pole cable, wherein said positive pole cable is connected to each said positive DC voltage output and said negative pole cable is connected to each said negative DC voltage output;
a positive bus bar connected to all said positive pole cables;
a negative bus bar connected to all said negative pole cables; and

a substation is connected to said MVDC cable system, said substation comprising multiple DC/DC step-up converters, said substation providing a plurality of feeder cables, each of which includes a positive feed cable connected to said positive bus bar and a negative feed cable connected to said negative bus bar, said plurality of feeder cables connected to a like number of said DC/DC step-up converters to step-up said medium voltage direct current to a high voltage direct current.

2. The system according to claim 1 , wherein said substation further includes a DC/AC converter connected to each said DC/DC step up converter to convert said high voltage direct current to a high voltage alternating current.

3. The system according to claim 1 , wherein each said DC/DC step-up converter comprises:
a substation DC/AC converter connected to said positive and negative bus bars and generating a converter output;
a transformer receiving said converter output to generate stepped-up voltage AC output signals; and
a substation AC/DC converter receiving said stepped-up voltage AC output signals to generate said high voltage direct current.

4. The system according to claim 3 , wherein each said DC/DC step-up converter incorporates a transformer connected to said positive and negative fees cables, each said DC/DC step-up converter stepping up said medium voltage direct current to a high voltage direct current.

5. The system according to claim 4 , wherein each said DC/DC step-up converter comprises:
a pair of substation DC/AC converters, each connected to said positive feed cable, each said substation DC/AC converter generating an AC voltage output;
said transformer having a first side connected to said negative feed cable and receiving said AC voltage outputs; and
a pair of substation AC/DC converters connected to a second side of said transformer, each output of said substation AC/DC converter connected to each other as a positive high voltage direct current, and a negative high voltage direct current connected to said second side of said transformer.

6. The system according to claim 1 , said substation further comprising:
at least one step-up circuit comprising:
at least two DC/DC step-up converters that have outputs that are serially connected to one another and generating a high voltage direct current wherein said DC/AC converter is connected to said at least two DC/DC converters.

7. The system according to claim 6 , wherein each said DC/DC step-up converter has a positive DC output and a negative DC output, wherein said positive DC output from a first said DC/DC step-up converter is connected to a positive input of said DC/AC converter, wherein said negative DC output from a last said DC/DC step-up converter is connected to a negative input of said DC/AC converter, and wherein each of said other negative outputs of said DC/DC step-up converters are connected to a positive output of an adjacent said DC/DC step-up converter.

8. The system according to claim 7 , wherein each said DC/DC step-up converter comprises:
a pair of substation DC/AC converters, each connected to said positive pole cable, each said substation DC/AC converter generating an AC voltage output;
a transformer, wherein a first side of said transformer is connected to said negative pole cable and receiving said AC voltage outputs; and
a pair of substation AC/DC converters connected to a second side of said transformer, each output of said substation AC/DC converter connected to each other to generate a positive high voltage direct current, and said second side of said transformer generating a negative high voltage direct current.

9. The system according to claim 8 , wherein all of said step-up circuits generate a substantially same value of said high voltage direct current.

10. The system according to claim 9 , wherein said transformer has a 1:1 step-up value.

Assignees

• Abb Research Ltd

Inventors

• Kim Hongrae
• Li Jun
• Wang Zhenyuan
• Carr Joseph A
• Aeloiza Eddy C
• Tremelling Darren D

Classifications

• H02M3/3372

  of the parallel type · CPC title

• H02J3/36 Primary

  Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links · CPC title

• Y02E60/60

  Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD] · CPC title

• H02J2101/28

  Wind energy · CPC title

• H02M2007/4835

  Electricity · mapped topic