TAPPING POWER FROM A HVDC TRANSMISSION SYSTEM

• US 20100091527A1
• Filed: 01/29/2007
• Published: 04/15/2010
• Est. Priority Date: 01/29/2007
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited (Hitachi, Ltd.)
• Original Assignee: ABB Technology Limited (ABB Ltd.)
• Inventors: Asplund, Gunnar
• Granted Patent: US 8,737,096 B2
• Time in Patent Office: Days
• US Class Current: 363/35
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• 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

An apparatus for tapping electric energy from an HVDC power transmission system includes at least one voltage source converter. The apparatus includes an intermediate ac network containing the voltage source converter, and a switching arrangement for disconnecting the intermediate ac network in dependence on the transmission direction of the HVDC power transmission system.

Claims

1. An apparatus for tapping electric energy from an HVDC power transmission system, comprising:

at least one voltage source converter,

an intermediate ac network comprising the voltage source converter, and

a switching arrangement configured to disconnect the intermediate ac network in dependence on the transmission direction of the HVDC power transmission system.

2. An apparatus according to claim 1, further comprising:

a plurality of intermediate ac networks, each feeding power to one phase of a local ac network.

3. An apparatus according to claim 1, wherein the switching arrangement comprises a switch configured to reconnect the apparatus with changed polarity to the transmission system.

4. An apparatus according to claim 1, further comprising:

a switch configured to form a first current path.

5. An apparatus according to claim 1, further comprising:

a switch configured to form a second current path.

6. A method for tapping electric energy from an HVDC power transmission system by connecting an intermediate ac network comprising a voltage source converter, the method comprising:

providing a switching arrangement between the HVDC power transmission system and the intermediate ac network,

forming a first current path including the voltage source converter,

sensing the transmission direction of the HVDC power transmission system, and

disconnecting the ac network from the HVDC power transmission system as a response of a changed polarity of the transmission system.

7. The method for tapping electric energy according to claim 6, further comprising:

forming a second path including the voltage source converter in response to a changed polarity of the transmission system.

8. A computer program product, comprising:

a computer readable medium; and

computer program instructions recorded on the computer readable medium and executable by a processor for making the processor carry out a method comprising providing a switching arrangement between an HVDC power transmission system and an intermediate ac network comprising a voltage source converter, forming a first current path including the voltage source converter, sensing the transmission direction of the HVDC power transmission system, and disconnecting the ac network from the HVDC power transmission system as a response of a changed polarity of the transmission system.

9. The computer program product according to claim 8, wherein the computer program instructions are provided at least in part over a network.

10. The computer program product according to claim 9, wherein the network comprises the internet.