The frequency-locked loop (FLL) is widely utilized in grid synchronization to rapidly and accurately acquire grid voltage and frequency information. However

obtaining the desired dynamic response remains challenging due to the need for balancing diverse performances through adjusting FLL parameters. This paper proposes a frequency-locked loop technique compatible with standardized filter design approaches. Initially

a small-signal model is employed to design a frequency observation loop capable of decoupling the dynamics of the pre-filter. This enables the independent design of filters within the frequency observation loop

not only facilitating the filtering within the frequency-locked loop but also allowing for flexible adjustment of filter parameters. This approach reduces computational complexity while enhancing filtering performance and enabling the observation of the rate of change of frequency (RoCoF). Finally

two filters are designed: high-order low-pass filter (HOLPF) and moving average filter (MAF). MATLAB/Simulink simulations and experiments are conducted to validate the effectiveness and accuracy of the proposed flexible dynamic FLL.