A Proposal for a PMU Based Adaptive Islanding Scheme for Mumbai City

A major grid disturbance occurred in the Mumbai region on 12th October 2020. The Mumbai islanding scheme could not ensure survival for this disturbance even though it has operated successfully in the past. One of the reasons is that the ratio of embedded generation to load has fallen over the years. This has led to very high ROCOFs being encountered during islanding. To improve the chances of survival in high ROCOF scenarios, the existing settings need to be modified to avoid excessive delays, and frequency thresholds need to be increased. However, during low ROCOF scenarios, the existing scheme may largely be retained to ensure a more secure operation. A scheme to implement adaptive settings for high and low ROCOF scenarios using PMUs is proposed in this paper. Simulations are performed to demonstrate the efficacy of the proposed scheme.