Two-channel multirate network equivalent aimed to real-time electromagnetic transient calculation

Abstract

A computationally efficient multirate scheme was proposed to model a linear and time invariant part of an electric network for electromagnetic transient calculation. The main contribution is expected in the field of real-time calculation, where very efficient models are required to fulfil stringent time performance requirements. Two models of the equivalent sub-network based on different time steps are implemented in the low- and high-frequency channels of a basic Laplacian Pyramid unit. A detailed model based on the longest time step reproduces the low-frequency response, while a simplified (lower order) model, based on the shortest time step, reproduces the high-frequency behaviour. In this way, an accurate response of the equivalent over a wider frequency range can be achieved as compared with previous proposals based on a single low-frequency channel. Also, the proposed scheme make a much greater flexibility in choosing the decimation factor possible as compared with a previous proposal of two co-authors based on a 2-fold decimated filter banks.