This Letter proposes a modified method for the dynamic harmonic analysis of signals with non‐stationary harmonics, which is based on the previously proposed multiple‐resonator observer structure. An optimisation technique is applied to reshape frequency responses of the basic transfer functions. This method, by using a parallel structure with common feedback, is very robust and, in addition, allows a reduction of the computational burden. The proposed method has been investigated for up to 64 harmonics, using LabView software package, under different conditions, and confirmed to be valuable and efficient tool for signal components estimation.