Wide-area synchrophasors protect and control Central America's power system stability

Abstract

The power system in Guatemala is part of the long, interconnected network in Central America that runs from the south of Mexico to Panama. This power system is connected to Mexico in the north and to El Salvador in the south. The power system in El Salvador is connected to the rest of the Central American countries in the south, all the way to Panama. The Guatemalan power system is a transmission corridor for power flowing from the abundant hydrogeneration resources in the southeast of Mexico, as well as a consumer of this power. The Guatemalan wide-area protection scheme (WAPS), called the wide-area supplementary control scheme (SCS), isolates the Guatemalan power system from the power system to the south of Guatemala when the scheme detects unstable operating conditions. This scheme is based on time-synchronized measurements of active power and modal analysis of the active power flow of the interconnection between Guatemala and El Salvador. Phasor measurement and control units (PMCUs) are installed at strategic buses in the Guatemalan power system. The strategic locations include the interconnections to Mexico and El Salvador. Operating modes in the power system that cause instability were identified based on operating experiences of the power system. The scheme detects unstable operating conditions and opens the interconnection with El Salvador to isolate the Guatemalan power system from the rest of Central America. This paper discusses details of the Central American power system, the deployment of PMCUs, a modal analysis-based scheme, and the communications network of the scheme. It also presents events that show how the active power-based and modal-analysis based SCS avoided power system collapse.