Power System Frequency Control under Large Frequency Difference Disturbance

With the normalization of cross-regional power transmission and the high proportion of new energy sources connected to the grid, the frequency fluctuation range of the grid has increased, which led to higher requirements for the frequency modulation speed and stability of the main regulating resources especially thermal power units. In this paper, we study the dynamic frequency characteristics of the hybrid grid, and propose a frequency control method for thermal power units based on frequency difference signal in large disturbance environments. By introduce multi-level forward feedback and difference-based feedback controllers on the turbine side, boiler side and auxiliary control side, the unit's frequency modulation performance is further optimized. Test results show that this control strategy effectively improves the response speed of the primary frequency modulation while ensuring the control stability.