Rate of Change of Frequency $($RoCoF$)$ is a significant issue for the transmission

system operator $($TSO$)$ in Ireland. Briefly describe the problem and identify the reasons

for its growing significance in recent years. How is it related to the System Non$-$

Synchronous Penetration $($SNSP$)$ levels? What options are open to the TSO in dealing

with high levels of RoCoF?