A Hydro-Thermal Scheduling Model for the Hydro-Québec Production System

This paper summarizes the results of several years of effort for designing and implementing a model for the mid-term hydro-thermal scheduling of resources at Hydro-Québec. The horizon ranges from one to two years with weekly time steps and the input data are assumed known with certainty. The model can handle a detailed representation of the hydraulic system, including delays between sites. The non-linear nature of production curves of hydro plants is modelled explicitly while different types of thermal equipment, import and export markets can be used to resolve the differences between hydro production and firm load. The solution technique uses a first order non-linear programming approach which yields short solution times for the whole Hydro-Québec system. The program is part of a larger system for data handling and report generation. The model is presented together with a description of the supporting data management system. The major problems met during the first years of operation will be exposed with the solutions selected. Future developments will be discussed.