Assessment of the impact that individual voltage source has on a generator´s stability

This paper presents an approach for splitting equivalent Thevenin voltage into components induced by each voltage source in the reduced grid. Thevenin equivalent representation of the system is sometimes used for stability assessment of a given generator, where the Thevenin voltage is one of the key variables affecting the stability conditions. Thevenin voltage is formed by components induced by each voltage source in the grid, while depending on topology and system parameters, the impact of these components on the equivalent Thevenin voltage E_th might vary considerably. This paper demonstrates how the impact of individual voltage source to E_th might be defined utilizing system admittance matrix. Knowledge about alternation of E_th, while applying changes to either the admittance matrix or the generators´ excitation and torque, gives a promising perspective for determination of effective countermeasures aimed at preventing instability. Suggested approach for E_th decomposition is applied to the IEEE 30 bus test system.