A new perspective on frequency control in conventional and future interconnected power systems

Abstract

In the interconnected power systems, the frequency change during disturbances may manifest differently in certain areas in the initial moments after the disturbance. Due to wave propagation, generating units located in distant areas contribute to primary frequency control (PFC) with a certain time delay. To address this issue, this study presents a novel primary frequency control (PFC) mechanism that enables generators in remote areas to adjust their output power before the disturbance wave propagates to that area. This mechanism leverages the use of PMU systems to enable early power adjustments. The proposed PFC mechanism is applicable to both conventional interconnected power systems and future systems with a significant share of converter-based technologies. The effectiveness of the method is demonstrated through simulations conducted on a two-area power system model, showing a 15 % reduction in maximum frequency deviation compared to the conventional method. This improvement results in a lower frequency nadir, offering the potential for a decrease of frequency nadir of up to 0.2 Hz when the disturbance causes the frequency drop to 49 Hz.