ADAPTIVE NETWORK PROTECTION IN MICROGRIDS
ABSTRACT
Microgrids comprise low voltage distribution systems with distributed energy re-
sources (DER) and controllable loads which can operate connected to the medium
voltage grid or islanded in a controlled coordinated way. This concept aims to
move from connect and forget philosophy towards an integration of DER. Mi-
crogrids are expected to provide environmental and economic benefits for end-
customers, utilities and society. However, their implementation poses great techni-
cal challenges, such as a protection of microgrid. Local generation in a combina-
tion with a possible islanded operation can pose protection sensitivity and selectiv-
ity problems in case of fault depending on the relay settings.
This paper presents a novel adaptive microgrid protection system using digital
relaying and advanced communication. The protection system is based on a cen-
tralized architecture where relay protection settings are modified centrally with
regard to a microgrid operating condition.