This paper describes the experience obtained during the deployment of a supervision system in a real network in a medium size city located in the Mediterranean coast of Spain. It was necessary to develop different solutions that took into account the diversity of installations derived from the technical history of the utility owner of the network. A wide range of technologies were used to get an optimized application: electromagnetic sensors, materials engineering, Ethernet, power line communications, IEC 61850…

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Electric power systems are susceptible to frequency variations. While the US grid generally exhibits a very stable frequency during all but emergency conditions (such as cascading black-outs) there are regions in some countries in which such variations are extremely notable and recurrent and experience from these applications provide very good data for improving protection design.

Proper protective relay behavior is of key importance to minimize system degradation and to stabilize the system as quickly as possible. Incorrect relay response during frequency excursions is bound to aggravate an already deteriorating situation.

This paper describes how conventional distance protections are affected by frequency variations and how digital technology allows designing reliable protective relays that will behave correctly under such conditions.

Real cases are used for illustration, showing distance protection operations without any provisions for frequency changes. The cases are reevaluated with the same distance protection after adding adaptive algorithms to track system frequency.

The paper includes a description of the problems encountered when implementing the adaptive frequency tracking algorithms and the solutions chosen to ensure reliability independent of system conditions.

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This document describes the procedures required to interface with SEL communications processors utilizing the ZIVercom software Version 1.90 and up (older versions can be used but require Patch 20 and up to incorporate the SEL2030 module). The procedures listed below are specific to the SEL 2030, but can also be applied to the SEL 2020.

Download PDF file (Interfacing ZIV relays with SEL communications processors) 1 MB

ZIVercom® is a powerful, user friendly software package intended to aid the user with setting changes, data collection and oscillography (optional). Settings can be made off line and downloaded locally or remotely, or can be made while being physically connected to the relay.

Download PDF file (BCD_QSGuide) 2.1 MB