To solve the problem of difficult frequency control in power systems caused by complex and variable loads

it proposes an load frequency automatic control method considering output constraints.This method introduces the Prony algorithm to decompose the dynamic signal of the system load and extracts its modal features.It designs PID instructions and executes them through the governor to achieve closed-loop automatic control of frequency.The experimental results show that the deviation of this method in the load frequency feature extraction stage is only 2 Hz.In the load sudden change test

this method can stably control the system frequency around 50 Hz

and the fluctuation amplitude is much smaller than that of the traditional method.The proposed method achieves high-precision and strongly robust control of load frequency under strict physical constraints by integrating precise output constraint modeling with Prony feature extraction.