Abstract: Hydrogen energy with advantages such as high calorific value and zero-carbon emission can provide high-quality frequency regulation resources for microgrids. However, safety constraints such as response frequency and ramp rate of power-to-hydrogen (P2H) devices pose challenges to load frequency control (LFC) strategy design in microgrids. This paper proposes an adaptive event-triggered LFC design scheme for microgrids. Firstly, a bilateral adaptive event-triggered LFC communication scheme is designed for microgrids. The operating power points of frequency regulation devices including P2H devices can be adjusted only when the control performance is degenerated below the preset level, which effectively reduces the action frequency of P2H devices. Secondly, considering the ramp constraints of P2H devices, the event-triggered LFC system in microgrids is modeled as a saturated nonlinear model. Finally, the design criteria for event-triggering and controller parameters are determined by constructing a Lyapunov function. Simulation results show that P2H device participation can decrease the frequency deviation amplitude of the microgrid by 6.24% and shorten the settling time by 1.55%, thereby effectively enhancing the frequency stability of the microgrid.

Key words: microgrid, load frequency control, power-to-hydrogen, event-triggered control, ramp constraint