Control Hardware-in-the-Loop Simulation on Fast Frequency Response of Energy Storage System Equipped with Advanced Frequency Detection Algorithm

Fast frequency response (FFR) of Energy Storage System (ESS) is regarded as effective way to mitigate the system frequency deviation induced by fluctuation of power generation from the increased renewable energy resources and the impact of reduced system inertia caused by decreased synchronous generators. However, existing standards which refer to technical requirements for frequency measurements seem not to be specific for the frequency measurement used for plant power output control. In order to realize FFR of ESS, this paper proposes improved frequency measurement logic based on phase locked loop (PLL), and has conducted benchmarking against existing PLL and discrete Fourier transformation based frequency measurement logics. Finally, FFR performance of ESS with each frequency measurement logic has been tested in Control Hardware-in-the-Loop (CHIL) simulation. This CHIL composes of the actual Power Plant Controller (PPC), the actual inverter control board and the real time simulator. In CHIL experiments, several system disturbance situations which are likely to happen in actual power systems have been considered as test cases, and measurement accuracy and latency of each frequency measurement logic is evaluated. Also, plant power output control performance of ESS based on predefined FFR curve has been experimentally confirmed by closed loop power control simulation with CHIL environment. In conclusion, this paper reveals the effects of frequency measurement accuracy and latency on FFR performance of ESS, and proposes considerations for frequency measurement method used for FFR.