RT21 | Validating Inertia Emulation Controllers using Rapid Control Prototyping and PHIL Testing

Low-inertia power systems can experience high rates of change of frequency and large frequency deviations during power imbalances. Inertia emulation using high power density storage systems such as a Flywheel Energy Storage System (FESS), can help limit the rate of change of frequency following sudden changes in generation or demand. In this presentation, a new adaptive inertia emulation controller for a high-speed FESS is proposed. To validate the behavior of the FESS with the proposed control design, the controller is implemented on a real 60 kW high-speed FESS, using the concept of rapid control prototyping. The performance of the FESS, equipped with the adaptive inertia emulation controller, is evaluated by means of Power Hardware-in-the-Loop (PHIL) simulations using the real-time simulation model of a low voltage microgrid. To reduce the overall loop delay, the established PHIL setup uses fiber optic connections to the power amplifier and several I/O expansion units. The State-space Nodal (SSN) solver is also applied to reduce the simulation time step of the microgrid model. The results of PHIL simulation show that the FESS with the newly-proposed adaptive inertia emulation controller outperforms the previously-suggested adaptive control designs, in terms of reducing the maximum rate of change of frequency and limiting the maximum frequency deviation, while not demanding significantly more energy from the FESS.