The Influence of Network Factors on Frequency Stability

Retaining frequency stability is becoming increasingly challenging as the power system incorporates more non-synchronous generation. Assessing the frequency stability in a system has been predominantly completed by focusing on the quantity of connected synchronous kinetic energy in the system, or inertia. This traditionally was considered a function of generator construction – network factors typically were not considered. The research in this paper investigates how network topology, power flow, droop gain distribution, and inertia distribution all impact frequency stability. A generic four-area model has been created that allows discrete system setups. This research has shown that certain topologies lead to a more severe rate of change of frequency. A key finding is that the frequency drop is further increased when there is greater power flow into the area that experiences the disturbance. The extent to which the rate of change of frequency and frequency drop are influenced differently is emphasized, highlighting the need to procure different services depending on which metric is of primary significance at a specific location.