Performance Evaluation of BESS for Korean Power System Using Equivalent Power System Circuit Model

This paper describes a method of modeling power system elements involved in frequency-active power control using frequency data of south Korea power system. A particle swarm optimization method is used for estimating the parameters of the transfer function which illustrates the relationship between frequency and active power deviation. To obtain the optimal parameter estimation, we use the mean absolute percentage error (MAPE) index for evaluating the accuracy of estimation compared to real data. Real frequency and power data from KPX were used for comparison studies. From the proposed equivalent power system circuit model, we achieved 0.0052% MAPE compared to real data. To evaluate the BESS frequency regulation performance, we considered the BESS control algorithm which is based on the data of Korea electric power corporation (KEPCO). From this case study, we confirmed that the BESS which is operated in south Korea can improve frequency regulation in case of frequency event by increasing nadir frequency up to 0.0335Hz.