چكيده به لاتين
In the current thesis, in order to detect and isolate faults in photovoltaic-based DC microgrids, a protection method based on the similarity of transient fault currents on both sides of the fault line is presented, which is based on telecommunication systems. In the proposed method, at each moment, the average of consecutive current-derived samples on both sides of the line is calculated and compared with the predetermined threshold values. If the average of the samples on both sides of the line is positive and greater than the corresponding threshold values, the protection device sends a trip command to the circuit breakers on both sides of the line and the fault line is separated. This method is able to detect faults within one millisecond. In order to increase reliability, backup protection is provided in case the circuit breaker does not work properly, and in case of circuit breaker failure, an opening command is sent to all adjacent circuit breakers. As the proposed method is based on telecommunication systems, it needs a local backup protection. In this method, a local protection based on the first-order derivative of the current is considered, which is activated in case of failure of the telecommunication system and is able to detect and clear the fault. In order to validate the proposed method, a 4-bus DC network has been simulated in Simulink MATLAB software and the proposed method has been implemented on this network.
