Identification of System Exposure for the Northwest Region of Ethiopian Electric Power

Power system contingency is an operational state that can happen as a result of a system discontinuity and results in overall system voltage instability. The system has seen intermittent power outages in previous years, according to Ethiopia Electric Power. Parts of the grid system were disrupted during the event, and as a result, there was a partial blackout of the system. Therefore, research proposes identifying the system's exposure to lessen the likelihood of such accidents happening. The proposed method demonstrated on 15 bus system Northwest region of Ethiopia Electrical Power Network using DigSILENT software. System’s exposure was evaluated by using the voltage performance index and the overload performance index. The indices enable the evaluation of two distinct system stress signs, including voltage instability and overloads. Performance index data show that the BDII230 bus to the GoII bus line has highest performance index value (4.9488) from other for N-1 line outage circumstances. This indicates that BDII230 bus to the GoII is most dangerous line for interruption of Northwest region of Ethiopian Electric Power network. But the most sensitive bus for voltage limit violations on this condition are Gondar load bus and Metema load bus. Their voltage profile is 0.908 and 0.923 per unit, respectively. Also, for 50% load demand increasing conditions, Gondar load bus has highest performance index value (20.2352) compared to the other load buses and its voltage profile is 0.8879 per unit. So, applying performance index for Northwest region of Ethiopia Electric Power network is used to know the system performance such as voltage instability and overloading, for forecasting future operation and expansion planning of this area.