System and method of controlling current-limiters in ring systems

Patent metadata

Field	Value
Publication number	US-10074972-B2
Application number	US-201514688328-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Oct 16, 2012
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

An exemplary electrical network in form of a ring system includes a plurality of infeed transformers which are arranged in parallel between a sourcing busbar/cable system and a ring load busbar/cable system. A junction point connects each infeed transformer to the ring load busbar/cable system. The network includes a plurality of current limiters, where each current limiter is positioned between two junction points. Upon a fault event of an infeed transformer, two current limiters on both sides of a respective junction point of the faulted infeed transformer are simultaneously tripped in order to reduce current in the ring load busbar/cable system.

First claim

What is claimed is:

1. An electrical network arranged as a ring system, comprising:
a plurality of infeed transformers which are arranged in parallel between a sourcing busbar/cable system and a ring load busbar/cable system;
a junction point connecting each infeed transformer to the ring load busbar/cable system; and
a plurality of current limiters, wherein each current limiter is positioned between two junction points,
wherein, upon a fault event of a faulted infeed transformer, two current limiters on both sides of a respective junction point of the faulted infeed transformer are simultaneously tripped in one half cycle or less in order to reduce current in the ring load busbar/cable system.

2. The electrical network according to claim 1 , wherein the two current limiters on both sides of the respective junction point establish a respective protection zone, and an instantaneous current of a summation current of the respective protection zones defined by the current limiters is logically AND-combined with a rate of rise of the summation current of the respective protection zones.

3. The electrical network according to claim 1 , wherein the plurality of infeed transformers are arranged in parallel between the sourcing busbar/cable system and the ring load busbar/cable system, and wherein the ring load busbar/cable system includes three current limiters, each current limiter being positioned two junction points, and wherein current limiters on both sides of a respective junction point of a corresponding infeed transformer form a current limiter pair.

4. The electrical network according to claim 1 , wherein summation currents are evaluated to reduce a reaction time of further processing.

5. A method of reducing current in an electrical network arranged as a ring system, the network having a plurality of infeed transformers which are arranged in parallel between a sourcing busbar/cable system and a ring load busbar/cable system, a junction point connecting each infeed transformer to the ring load busbar/cable system via a junction point, and a plurality of current limiters, wherein each current limiter is positioned between two junction points, the method comprising:
simultaneously tripping two current limiters on both sides of a respective junction point in one half cycle or less upon a fault event of a corresponding faulted infeed transformer to reduce current in the ring load busbar/cable system.

6. The method according to claim 5 , wherein the two current limiters on both sides of the respective junction point establish a respective protection zone, the method comprising:
combining an instantaneous current of a summation current of the respective protection zones defined by the current limiters with a rate of rise of the summation current of the respective protection zones through a logical AND operation.

Assignees

• Abb Technology Ag
• Abb Schweiz Ag

Inventors

• Hartung Karl-Heinz
• Bockholt Ralf
• Grafe Volker

Classifications

• H02H9/02 Primary

  responsive to excess current {(current limitation for voltage regulators G05F1/573; disconnection after limiting H02H3/025)} · CPC title

• H02H3/44

  responsive to the rate of change of electrical quantities · CPC title

• H02H3/083

  for three-phase systems · CPC title

• H02H7/28

  for meshed systems · CPC title

• H02H7/267

  for parallel lines and wires · CPC title