Islanding detection reliability in electricity distribution network

Patent metadata

Field	Value
Publication number	US-9784781-B2
Application number	US-201414501984-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Mar 30, 2012
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A device for detecting an islanding condition in an electricity distribution network. The device comprises means for concurrently monitoring an islanding condition and a network event condition in the electricity distribution network, means for detecting an islanding condition in the power system network, and means for determining on the validity of detection of the islanding condition based on whether there is an associated network event with the detected islanding condition.

First claim

What is claimed is:

1. A device for detecting an islanding condition in an electricity distribution network, wherein the device comprises:
means for concurrently monitoring the islanding condition and a network event condition of the electricity distribution network;
means for detecting the islanding condition of the electricity distribution network; and
means for determining validity of detecting of the islanding condition based on whether there is an associated network event with the detected islanding condition.

2. A device according to claim 1 , wherein the device comprises:
means for providing an islanding indication when there is no associated network event.

3. A device according to claim 2 , wherein the device comprises:
means for accepting a detection of the islanding condition as a valid detection when there is no associated network event.

4. A device according to claim 3 , wherein the device comprises:
means for restarting a detection of the islanding condition when there is the associated network event.

5. A device according to claim 1 , wherein the device comprises:
means for accepting a detection of the islanding condition as a valid detection when there is no associated network event.

6. A device according to claim 1 , wherein the device comprises:
means for restarting a detection of the islanding condition when there is the associated network event.

7. A device according to claim 1 , wherein the device comprises:
means for concluding that an islanding detection is associated with the network event if the two conditions are detected within a predetermined time frame.

8. A device according to claim 7 , wherein the device comprises:
means for monitoring disappearance of the detected islanding condition which uses substantially inverse criteria than the detection of the islanding condition.

9. A device according to claim 8 , wherein the device comprises:
means for monitoring the islanding condition based on a voltage unbalance parameter and one or more voltage total harmonic threshold parameters.

10. A device according to claim 1 , wherein the device comprises:
means for monitoring disappearance of the detected islanding condition which uses substantially inverse criteria than the detection of the islanding condition.

11. A device according to claim 1 , wherein the device comprises:
means for monitoring the islanding condition based on a voltage unbalance parameter and one or more voltage total harmonic threshold parameters.

Assignees

• Abb Schweiz Ag

Inventors

• Laaksonen Hannu

Classifications

• H02J3/388

  Arrangements for the handling of islanding, e.g. for disconnection or for avoiding the disconnection of power · CPC title

• G01R31/40

  Testing power supplies (testing photovoltaic devices H02S50/10) · CPC title

• H02S50/00

  Monitoring or testing of PV systems, e.g. load balancing or fault identification · CPC title

• H02J3/38 Primary

  Arrangements for feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel · CPC title

• H02J2003/388

  Electricity · mapped topic