Background. The use of series compensation devices leads to an increase of the transmission line capacity. However, it also increases the risk of an oscillatory violation of the stability of the electric power system. Cumulative hunting and self-excitation of the system is observed in the systems with controlled series compensation devices with a high degree of capacitive compensation. It is known that automatic excitation control of generators partially eliminates the negative effect of series capacitive compensation on oscillatory stability. Therefore, when choosing the tuning parameters of controlled devices, it is necessary to consider their combined effect on the system modes. The developed methods to study steady-state stability make it possible to analyze the modes of power systems with controlled power transmission of various voltage levels. Thus, it is advisable to conduct a comparative analysis of the influence of the adjustable parameters of the series compensation device on the steady-state stability of systems of various voltage levels, considering synchronous generators automatic excitation control.
Materials and methods. Methods of mathematical modeling of the electric power system, the theory of long-distance power lines and electromechanical transients, methods of analyzing the stability of electric power systems are used. The original software in the C ++ programming language has been used as a modeling tool.
Results. The choice of controlled series compensation device and the automatic excitation control regulation laws parameters is made, provided that steady-state stability is maintained. The stability regions of the studied electric power-engineering system are constructed depending on the tuning parameters of the considered devices of various voltage levels. A comparative analysis of the characteristics of the modes of high and extra-high voltage lines has been carried out. The regulation coefficients values of controlled series compensation device and automatic excitation of generators have been determined, under which there is no violation of oscillatory stability for different voltage levels.
Conclusions. The conducted comparative analysis of the characteristics of high and extra-high voltage power lines demonstrates the need to consider the power transmission rated voltage when comprehensively selecting the tuning parameters of the controlled series compensation device and the automatic excitation control regulator.