The invention relates to the technical field of insulation
dielectric response characteristic identification and aging state evaluation of capacitive
power equipment, in particular to an extended
Debye model parameter identification method based on dynamic
modal decomposition, which comprises the following steps of: acquiring time-varying data of
depolarization current, constructing the time-varying data into a
Hankel matrix, and taking front N columns and rear N columns to form a matrix A and a matrix B; carrying out economic SVD
decomposition on the matrix A, setting a
singular value threshold value, abandoning singular values smaller than the
singular value threshold value, and reconstructing an SVD
decomposition matrix; solving X = A-1B, and then solving a characteristic value and a characteristic vector of X; solving modals of the X and sorting the X according to an energy decreasing sequence; the
modes are screened, the screened
modes are selected to restore the
depolarization current, the effect of dynamic mode decomposition is judged, and whether the
singular value threshold value is adjusted or not is judged according to the restoration effect; and calculating the number of branches, a
time constant and a relaxation
intensity coefficient of the insulation expansion
Debye model. The parameter identification result obtained through the method is clear in physical significance.