Optimal design of phase‐locked loop with frequency‐adaptive prefilter based on the accurate small‐signal model

Frequency-adaptive prefilters are widely used in the phase-locked loop (PLL) to suppress input disturbances. However, parameters of PLL and often designed separately or based on an inaccurate model. The positive feedback effect introduced by frequency adaption (FA) is usually ignored, leading non-optimal performance. Based accurate small-signal model with a particular focus FA, this paper proposes optimal design method for these advanced PLLs. dual second-order generalized integrator (DSOGI) taken as example demonstrate principle. With different gain margins, damping factors DSOGI PLL, well natural obtained using proposed method. Then global evaluating settling time overshoot. analysis shows that truly quite those provided literature, dynamic performance significantly enhanced without degrading steady-state Experimental results presented verify theoretical analysis.