An optimization model for regional generation scheduling at Hydro-Quebec

This paper describes the deterministic optimization model designed for regional generation scheduling at Hydro-Quebec. Its objective is to minimize generation losses, while enforcing provincial guidelines and detailed hydraulic constraints. The model also includes a constraint relaxation scheme based on constraints priorities. The solution method proceeds through three successive phases: Main Optimization, Unit Commitment Adjustment and Unit Loading Adjustment. Main Optimization deals with a sequence of nonlinear problems, by applying principles of successive linear programming and nonlinear separable programming and using the CPLEX linear optimization library as its basic tool. Unit Commitment Adjustment then heuristically improves the schedule implicitly provided by Main Optimization. Finally, given this improved schedule, Unit Loading Adjustment completes the process, by solving nonlinear problems where generation losses associated to non optimal loading of units are now precisely modelled.