Operation rules determined by risk analysis for special protection systems at Hydro-Québec

This paper describes a new approach used by Hydro-Québec to determine the rules of automatic devices installed in its main power plants to maintain secure operation under extreme contingencies. An example of application of this approach is given to illustrate how to apply data mining technique for the rules of the automatic generator rejection and remote load shedding system (RPTC: Rejet de Production et Télédélestage de Charges in French) installed at the Churchill Falls hydroelectric power plant (5500 MW) in Labrador. Real time snapshots of the Hydro-Québec power system collected over several years data have been used to generate large amounts of results (database) by transient stability simulations. The database is processed by the data mining software developed by the University of Liege to construct the decision trees. This approach gives the most relevant parameters and finds optimal settings for the RPTC system at the Churchill Falls, minimizing the number of generator rejection while maintaining the same performance in terms of security coverage. New operation rules have thus been established.