A Hybrid Framework for Adaptive Protection of Microgrids Based on IEC 61850

Microgrids can operate both in grid-connected and islanded modes. It is essential to protect microgrids against all types of faults in both of the operation modes. Conventional overcurrent protection schemes are not adequate for microgrids due to bidirectional flow of fault current and limited flow of fault current through semiconductor devices. In addition, the setting values of all the concerned relays need to be updated after any change in system operating conditions. Centralized and decentralized adaptive protection schemes are generally used for protection of microgrids. In this paper, a hybrid adaptive protection scheme has been proposed for protection of microgrids. Computational burden and data storage is distributed among the local controllers and the central controller. A gateway is proposed for communicating between the serial interfaced devices and the IEC 61850 process bus. Finally, a framework has been introduced for implementing the proposed hybrid protection scheme for adaptive protection of microgrids by using IEC 61850-based intelligent electronic devices (IEDs).