Impact of Inertia Distribution on Power System Stability and Operation

This paper presents the local inertia phenomenon which is related to the uneven distribution of inertia across a synchronized power system and its influence on the system stability and operation. This study explains that beyond the question of overall system inertia as required at the synchronous area level, the distribution of inertia may have an impact on the system local behaviour and operation particularly in smaller synchronous systems. In this area, some specific and relevant events observed by UK National Grid are simulated on a 36-zone GB transmission network reduced model to identify the possible effects due to an uneven distribution of inertia. In addition, in this paper, the accuracy of this model is verified and fine-tuned with the data obtained from real measurements. Based on the obtained results, higher local RoCoF, increasing the inter-area oscillations as well as changes in critical clearing time of tie-lines are the expected effects of local inertia phenomenon.