System analysis of electric power system stability by the Hurwitz criterion in mountain territories

Introduction. The article is devoted to the analysis of the stability of the electric power system (EPS) in mountainous areas using the Hurwitz criterion. In mountainous regions, the EPS faces a number of specific problems, such as complex terrain, remoteness of consumers and an increased probability of power transmission line failures. An important task is to develop a mathematical model that takes these features into account and to conduct an analysis of the stability of the system using the Hurwitz criterion. The purpose of the research: stability analysis of the system “high-pressure hydroelectric power plant – electric power system” using the Hurwitz criterion; identification of critical parameters of the system that affect its stability, and application of various optimization methods to improve the reliability and safety of the EPS in mountainous regions. Objects and methods. The object of the study is the high-pressure hydroelectric power plant (HPP) of PJSC RusHydro – Zaramagskaya HPP. The following methods were used for stability analysis: numerical modeling (integration of differential equations); state variable method; Laplace method; frequency response method; analytical methods for finding an exact solution to differential equations. Results and discussions. The results of the study demonstrate that the Gurwitz criterion is an effective tool for analyzing the stability of complex electric power systems, especially in mountainous areas. In the work, this method was successfully applied to analyze the static stability of the system taking into account automatic excitation control. Conclusion. A mathematical model has been developed that takes into account the specific conditions of mountainous areas. An analysis of the static stability of the system has been conducted taking into account the automatic excitation control (AEC). Critical parameters that affect the stability of the system, such as the load angle and the AEC gain factors, have been identified. It has been shown that increasing the accuracy of voltage maintenance can lead to a violation of stability in high-load modes. A method has been proposed for determining the minimum permissible gain factor, which allows avoiding aperiodic instability. Prospects for further research. In the future, possible alternative methods of stability analysis should be considered, such as frequency methods or methods based on Lyapunov theory, which could complement the results obtained using the Hurwitz criterion. A more detailed dynamic stability analysis should also be presented, which could provide a more complete understanding of the system’s behavior in transient conditions.