Implementing a country-wide modular remedial action scheme in Uruguay

Abstract

This paper presents a country-wide remedial action scheme (RAS) implemented in Usinas y Transmisiones Eléctricas (UTE) in Uruguay. When a single contingency or multiple closely timed contingencies occur, the RAS protects the power system from thermal damage to lines, voltage collapse, generation load unbalance, and overvoltage/undervoltage conditions. The RAS consists of six different schemes operating independently and, in certain cases, simultaneously to calculate power system states and define the remedial actions. Operator-defined gain constants and zone priorities are used to calculate the amount and location of load to shed respectively. Supplementary control modules such as the Brazil power exchange override are used to reduce the amount of load shed. The line-shed module prevents power oscillations on the Uruguay to Argentina interconnections. The post load-shed reactive power compensation module improves system voltage profile and eliminates possible overloads that could still be in the system.