Power system inertia estimation: Utilization of frequency and voltage response after a disturbance

Power system inertia is gradually being reduced due to the ongoing replacement of conventional synchronous power plants by intermittent generation. This affects the frequency response of the system and necessitates the estimation of power system inertia, so that sufficient power reserves are retained. This paper contributes with a novel disturbance-based inertia estimation method, that simultaneously estimates the power change after a disturbance. The proposed method accommodates the frequency and voltage dynamics, which significantly affect the system's power change, and hence the inertia estimation. Two separate approaches - that are also capable of standing alone - are combined, in order to accommodate the dynamics. An extended version of the Nordic32 test system is used for the application of the method, where several case studies and a comparison are investigated, so as to examine the method's accuracy and robustness.