Aggregation of a generic high-voltage network using the grey-box approach for dynamic frequency investigations

Inhalt:
In the increasingly complex power system, the impact of active distribution networks is becoming more relevant for dynamic studies in the transmission grid. As there is usually only limited data available on distribution networks, this paper investigates the aggregation of a generic 110 kV network using a grey-box approach. Therefore, a detailed generic high-voltage network and a single-machine dynamic equivalent are modeled in Matlab/Simulink. The parameters of the dynamic equivalent are estimated using a curve-fitting procedure based on particle-swarm optimization (PSO). The ob-jective function of the optimization is the frequency curve after a load step. Secondary conditions are the exchanged active and reactive power with the overlaying transmission grid. The quality of the dynamic equivalent is tested for different numbers of parameters to be fit and different settings of the PSO. Results show that the frequency curve can be met by the aggregation model with only small deviations and that the number of parameters to be optimized, the PSO settings as well as the initial values of the parameters to be optimized have an impact on the aggregation results.