Fuzzy Logic based Adaptive Protection Scheme for Smart Microgrid

This study proposes a fuzzy based adaptive protective relaying scheme for fault detection and fault classification of microgrid. This scheme also isolates the microgrid from the utility grid by disconnecting the static-switch on detecting the presence of fault on utility grid. An adaptive fuzzy inference system module (AFIS-Module) has been developed using a separate fuzzy rule base for the two modes of operation of microgrid, i.e. islanded mode and grid connected mode. Centralized Communication unit monitors the status of Point of Common Coupling and sends a command signal to the relays so that the relay settings are updated with new rules for any transition in the mode of the microgrid. The fundamental phasor, amplitude and zero sequence components of current signals are used as input features for fault detection and fault classification. Using MATLAB/SIMULINK a standard microgrid model IEC 61850-7- 420 was simulated. The proposed method is tested for all types of fault and results were obtained. The results showed a great level of effectiveness to accurately identify faults and trigger the opening of the right circuit breaker/s under different operation modes and other system disturbances.