Each actual power system part is part of an interconnected system. Though, one of the main parts of the power system is the safe operation of its protection unit. In order to avoid widespread outage in the power network, interruption of system and their influxes on the protection unit performance must be evaluated. [17-18], theThe decrease of network for short-circuit is an algorithm based on nodal impedance/nodal admittance matrices. The simple clue is that the impedance matrix of the equivalent network, measured at the connection points in the retained network, must be equal to the impedance matrix of the network to be reduced (corresponding to the row and column of the boundary node). [3]. During operation of the power system there may be, a short-term impact occurringmay occur in the system from a steady-state transition to another new factor. One of the causes of these transient events could be a short circuit. As an important component, it determines the performance of transmission lines, directly affectsaffecting the reliability of the power system. [19-20], Therefore, one of the most important tasks, when planning and operating power systems is the short – circuitshort-circuit calculations. [21], inIn reality, in order to study a short-circuit fault, it's necessary to only focus only on the region where the fault is located. The main function of power system planners and operators is to define accurately define how much power can be safely be transferred across the system. Also, protecting devices must be able to clear any available fault current in the system safely. [22-23], Power system planning and design under normal steady-state operation; the system should be able to meet the requirements of transmitting necessary electrical energy to users. In case of failure, the power system shall meet the safety requirements.