Abstract
Ensuring the safety and security of strategically important facilities, such as power system elements and estimation of the energy security level is important for the country. In this paper, we analyze the congestion risks of Kazakhstani high-voltage transmission lines by applying the "N-1 security" assessment approach for peak annual consumption hour in the winter. The assessment is performed based on the power system model with detailed network topology assuming direct current load flow for optimal power flow approximation. The model is implemented in GAMS and serves as a core for iterative algorithms simulating potential failure of lines and corresponding topology changes. The results provide insights into possible outages up to maximum allowable permissible current in the transmission lines and criterion of the ability to maintain the stable operation of the power system in the event of a single line break. The proposed method provides the ability to find weak overloaded connections for decision-makers to reduce risks in critical areas and find preventive measures against cascading failures. The analysis has shown that using precalculated optimization methods can reduce the probability of the overloading of the HV lines in the event of a breakage of one of the lines.