Anti-islanding protection in distributed generation with synchronous generators

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CIRED 2019 - 1730.pdf (1.05 MB)

Paper number

1730

Working Group Number

Conference name

CIRED 2019

Conference date

3-6 June 2019

Conference location

Madrid, Spain

Peer-reviewed

Yes

Short title

Convener

Authors

Kulis, Ivan Goran, Koncar-KET, Croatia
Boras, Miljenko, Koncar-KET, Croatia

Abstract

Anti-islanding protection methods are not always reliable due to the existence of non-detection zones (NDZ) in which active and reactive power production and consumption in the rest of the network (island) are close to or are in balance. This problem is especially noticeable when it comes to DG with synchronous generators (for e.g. small Hydro Power Plant (HPP) or Thermal Power Plant (TPP) with cogeneration).Usage of the rate of change of frequency (ROCOF, 81R) has been proven as the most reliable method for undesired island operation detection. But the ROCOF also has its sensitivity limits especially when it comes to synchronous generators which tend to keep their stability on the network. The problem is further enhanced in a week networks (networks with small SC power) where ROCOF can’t be set very sensitive because there are frequency changes even in parallel operation caused by disturbances during bad weather conditions or by load switching.In the article are shown different ROCOF methods and settings with their field test and operational results on small HPP and cogeneration TPP. The method which includes machine automatic voltage regulation (AVR) influence is also described. The intention is to reactive power set point should be periodically changed (≈200-400 ms) in small amount (few (tenths) kVAR). When PP operates in parallel with the network small changes in reactive power have a small (almost negligible) influence on voltage and current but upon islanding this influence rising and consequently cause bigger change of active power and frequency.

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Keywords

Publisher

AIM

Date

2019-06-03

Published in

CIRED 2019 Conference

Permanent link to this record

https://cired-repository.org/handle/20.500.12455/541
http://dx.doi.org/10.34890/768

ISSN

2032-9644

ISBN

978-2-9602415-0-1