DC Microgrid Ripple Detection Algorithm Based on SGMD-HT Algorithm

In this paper, a ripple parameter measurement method based on the combination of Adaptive Sim Geometric Modal Decomposition and Hilbert Transform (ASGMD-HT) is proposed. It is applicable to the problem that ripples are difficult to be extracted in strong noise environments. First, the reconstructed trajectory matrix is constructed based on the Hamiltonian matrix with Sin QR decomposition, and the initial Sin geometry components are obtained by combining the Sin geometry similarity transform. Second, the initial Sin geometry components are fitted according to the similarity criterion and the residual components are calculated, and then the trajectory matrix is constructed based on the residual components. Then, the above operations are repeated until the iteration termination condition is satisfied to obtain the final mutually independent ripple components. Finally, the ripple parameters are extracted by Hilbert transform. The analysis results of simulation and measured data show that this method can accurately detect ripples under strong noise conditions.