Review of anti-islanding techniques in distributed generators D. Velasco a, *, C.L. Trujillo a,b , G. Garcera ´ a , E. Figueres a a Grupo de Sistemas Electro ´nicos Industriales del Departamento de Ingenierı´a Electro ´nica, Universidad Polite ´cnica de Valencia, Camino de Vera S/N, C.P. 46022, Valencia, Spain b Departamento de Ingenierı´a Electro ´nica, Universidad Distrital Francisco Jose ´ de Caldas, Carrera 7 No. 40-53 Piso 5, Bogota ´, Colombia Contents 1. Introduction .................................................................................................... 1608 2. Local islanding detection techniques ................................................................................ 1609 2.1. Passive techniques of islanding detection ....................................................................... 1609 2.1.1. Over/under-voltage and over/under-frequency ........................................................... 1609 2.1.2. Phase jump detection ............................................................................... 1610 2.1.3. Detection of voltage and current harmonics ............................................................. 1610 2.1.4. Detection based on state estimators .................................................................... 1610 2.2. Active techniques for islanding detection ....................................................................... 1610 2.2.1. Impedance measurement ............................................................................ 1611 2.2.2. Harmonic injection/detection of impedance ............................................................. 1611 2.2.3. Sliding mode frequency shift (SMS) o active phase shift (APS) ............................................... 1611 2.2.4. Active frequency drift (AFD) .......................................................................... 1611 2.2.5. Frequency jump .................................................................................... 1612 2.2.6. Sandia frequency shift (SFS) .......................................................................... 1612 2.2.7. Sandia voltaje shift (SVS) ............................................................................ 1612 2.2.8. Mains monitoring units with allocated all-pole switching devices connected in series (MSD) ...................... 1612 2.2.9. Variation of active power and reactive power ............................................................ 1612 2.2.10. General electric frequency schemes – GEFS .............................................................. 1612 3. Remotes techniques of islanding detection ........................................................................... 1612 3.1. Impedance insertion ........................................................................................ 1612 3.2. Power line carrier communications ............................................................................ 1613 3.3. Signal produced by disconnect ................................................................................ 1613 3.4. Supervisory control and data acquisition (SCADA) ................................................................ 1613 4. Conclusions .................................................................................................... 1613 Acknowledgements .............................................................................................. 1613 References ..................................................................................................... 1613 1. Introduction In recent years, a major global priority is the development of renewable energy. These energy sources produce low pollution compared with fossil fuels. From this point of view the distributed Renewable and Sustainable Energy Reviews 14 (2010) 1608–1614 ARTICLE INFO Article history: Received 2 December 2009 Accepted 16 February 2010 Keywords: Islanding detection Distributed generator ABSTRACT In this paper a revision about different techniques for islanding detection in distributed generators is presented. On one hand, remote techniques, not integrated in the distributed generators, are discussed. On the other hand, local techniques, integrated in the distributed generator, are described. Furthermore, it is discussed how the local techniques are divided into passive techniques, based on exclusively monitoring some electrical parameters, and active techniques, which intentionally introduce disturbances at the output of the inverter, in order to determine if some parameters are affected. ß 2010 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +34 96 38 79 606. E-mail addresses: davede@posgrado.upv.es (D. Velasco), cltrujillo@udistrital.edu.co (C.L. Trujillo), ggarcera@eln.upv.es (G. Garcera ´), efiguere@eln.upv.es (E. Figueres). URL: http://www.gsei.upv.es Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser 1364-0321/$ – see front matter ß 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.rser.2010.02.011