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Data packets based high-speed digital communications have opened the door for new types of applications in power system protection and control. The main obstacle in adopting Ethernet-type networks for time-sensitive communications was the data transfer characteristic of these networks. With baud rates in the gigabit-per-second range, the industry has started adopting the Ethernet networks as a viable alternative, not only because of their lower cost. This paper presents an open-system approach in which protective hardware equipment is designed to work in a clustered environment, sharing resources, data, and diagnostic functions with similar units. The Ethernet network, being capable to accommodate transparently a wide range of protocols, is used to connect the protective hardware. A model was developed for the Ethernet network to be incorporated into the power system simulation. The characteristics required from a digital relaying algorithm to be able to work with signal samples sent across data packets based networks are described in this paper. The proposed solution is implemented using a modified adaptive least-square-error algorithm and tested on a protection system that was integrated into the power system model. Index Terms--Data communication, open systems, power system protection, power system relaying, protective relaying, sampled data systems.

It has been recognized that the cross-magnetizing phenomenon of saturated synchronous machines plays an important role in their analysis using the two-axis frame models. In this paper, the finite-element method (FEM) is applied to determine from 2-D static electromagnetic field solutions the parameters representing this phenomenon. A specially designed synchronous machine that can be excited from both its direct and quadrature axes is used in this study in order that the parameters representing the cross-magnetizing effect could be measured experimentally and, thus, the accuracy of the numerical solution can be verified. The effects of some of the factors that may affect the accuracy of the FEM analysis have also been investigated. The results of these studies have shown that the calculated parameters representing the cross-magnetizing phenomenon using the FEM are consistent with the measured values. [ABSTRACT FROM AUTHOR]