Interrelation between inertia and frequency-dependent active power control in case of system splits

The decline of system inertia is a recognised consequence of the increased use of renewable energies that do not drive tur- bines and, therefore, do not include connected rotating masses. As a result, electrical energy systems are confronted with higher frequency gradients and significant frequency deviations that reduce the system’s stability. Nevertheless, systems with a high share of renewables with all their specific characteristics must guarantee the same reliability as conventional power systems. Consequently, new control strategies and security mechanisms for inverter-based resources (IBR) must be developed to prevent substantial disruptions, like system splits with widespread blackouts. While current research focuses mainly on providing addi- tional inertia, this paper aims to investigate which significance long-standing established frequency-dependent power control mechanisms with accelerated reaction times take to maintain system stability of the Continental European (CE) grid. There- fore, a simplified yet realistic model is developed and parametrised to be examined in an exemplary study case. Analysing the dynamic frequency deviation explicitly derivates the influences of providing additional inertia and accelerating frequency- dependent active power control. Thus, it is revealed that both measures are indispensable for future grids and that they must be coordinated to complement each other.