Application of the Inventory Method to Estimate the Inertia of the Hungarian Power System

In the world, and also in Hungary, power electronics inverter equipment appears with an increasing share in electricity generation, while the share of traditional rotating machine solutions is decreasing. As a result of decreasing mechanical inertia, the speed of frequency changes increases even in the event of a temporary tilt in the production-consumption balance. This also affects traditional power–frequency control. In addition, the protection settings need to be reviewed, the stability of the system decreases, and the system can easily reach the Emergency Frequency Control Scheme (EFCS) and Load Shedding Automatics’ limits. Currently, inertia loss is not a threat at European level (ENTSO-E), but monitoring is important in the subsystems that make up the European system (TSO). We review the methods of maintaining and increasing inertia and propose a simple inventory-based inertia state estimation method.