The Impact of Energy Storage System Control Parameters on Frequency Regulation Strategies

The large-scale development of battery energy storage systems (BESS) has enhanced grid flexibility in power systems. From the perspective of power system planners, it is essential to consider the reliability of BESS to ensure stable grid operation amid a high reliance on renewable energy. Therefore, this paper investigates BESS models and dynamic parameters used in planning future grids from the viewpoint of power planners. By measuring output response data from BESS units of three companies, dynamic responses are converted into WECC second generic model parameters using optimization algorithms, allowing their use in power system analysis software. Subsequently, using Taiwan's actual power system as the simulation background, N-1 simulations are conducted to explore the impact and benefits of BESS parameters when implementing frequency regulation strategies under two different BESS capacity specifications: 2 MW and 10 MW. In the 2 MW scenario, a comparison of the parameters from the three BESS units under frequency regulation strategies shows slight differences in the rise times of their output responses. However, for a 2 MW capacity, the frequency nadir in the power system remains consistently at 58.692 Hz. The simulation results based on the parameters defined in this research demonstrate the importance of using accurately measured and solved parameters in simulations. In the 10 MW scenario, the BESS capacity can offset the generator trip capacity, thereby revealing differences in response time between different parameters, with the frequency nadirs for the solved parameters being 59.755 Hz, 59.773 Hz, and 59.762 Hz, respectively.