Digital Dispatch (Finland)

To deal with the coming of Variable Renewable Energy (VRE) integration in the Java-Bali Power System, the moment of inertia becomes one of the challenges to be considered. The inertia moment is related to the ability of a system to maintain the stability of frequency when a power imbalance occurs in the system. According to that challenge, several factors affect the amount of inertia moment, such as the number and types of generators and the load characteristics connected to the grid. The ability of the system to prevent system collapse is stronger when the inertia is high. In Java-Bali Power System, the stiffness index uses a historical and statistical method in MW/Hz. In this research, another approach to measure the stiffness index is performed. The method calculates the correlation between the moment of inertia and the Rate of Change of Frequency (RoCoF) in Hz/second. Manual computations are used to determine the RoCoF and inertia moment in the system utilizing statistical data from a few previous disturbance events. These calculations will obtain the minimum value of system inertia during peak and off-peak load periods. At the peak load period, the requirement of minimum inertia is 141,768 MVAs, while the off-peak load minimum inertia is 98,931 MVAs. Therefore, those inertia values will become the Dispatcher’s awareness parameter while controlling the real-time operating system.