Novel maximum transient frequency deviation estimation in island grids using performance and correction indices based on field tests

Preparation for a potential blackout has gained increasing significance in recent years. As a result, the blackstart and islanding capabilities of power plants within the distribution and transmission grid become more important. Due to the high level of organisational and monetary effort required, such blackstart and grid restoration functionalities are infrequently trained in real-world scenarios and data is mostly derived from simulations. This paper analyzes some of the few existing field tests concerning load-frequency response. The study aims to compare different grid configurations, participating power plants, turbine types, and ramp-up processes. Key findings are explained using two novel indices: the Turbine Type Performance Index (TTPI), which serves as a comparative index for the turbine controller performance, system rotational energy, and load-frequency response. The second index, the Load Behavior Correction Index (LBCI), ensures the conversion of non-instantaneous power changes to instantaneous power steps and thus enables the estimation of the maximum transient frequency deviation with the direct connection of induction machines via a defined TTPI. The primary advantage of this paper’s findings is to provide a fast estimation of the maximum transient frequency deviation resulting from defined load steps based on the given rotational energy of the system.