A framework to assess the effect of reduction in inertia on system frequency response

This paper presents a framework to analyze the impact of different penetration levels of renewable generation sources (RES) and consequent reduction in inertia on grid frequency. The developed methodology is demonstrated using three operating conditions of the network. For each operating condition, the decrease in the network loading is balanced by disconnecting a part of synchronous generation. To establish the critical penetration levels of renewables and inertia limits for the grid frequency, the uncertainty of loads, intermittent and stochastic patterns of RES generation around each operating condition are simulated. The results clearly identify the critical penetration levels of RES and reduction in inertia limits of the system for frequency stability. In addition, the performed analysis quantifies the effect of primary frequency response and reduction in inertia on frequency nadir. The proposed framework is applied to the modified 16 machine and 68 bus network.