A Data Passivity-Enforcement Preprocessing Approach to Multiport System Modeling

The passivity enforcement problem is always a key issue when estimating passive black-box models. Passivity has been broadly scrutinized in the literature and is known to yield stable time-domain simulation; thus, passivity is a much-desired model property which cannot remain an unmodeled effect. Many successful algorithms exist that accomplish the enforcement task by model parameter perturbation, with the caveat that the passivity violations to be suppressed are not large. This paper proposes a novel approach to address this issue. We propose four different mathematical formulations to preprocess the measurement of admittance parameters. Preprocessed data serve as inputs to parameter estimation algorithms to obtain passive models for power system applications. This approach is particularly adequate to use with model parameter perturbation methods. Three examples containing data of actual measurements illustrate the advantage of using the proposed methodology.