A practical hydro, dynamic unit commitment and loading model

We describe the Dynamic Unit Commitment and Loading (DUCL) Model that has b een developed for use in real-time system operations at BC Hydro (BCH) to d etermine the optimal hydroelectric unit generation schedules for plants wit h multiple units and complex hydraulic configurations. The problem is formu lated and solved with a novel procedure that incorporates three algorithms. First, an expert system is used to eliminate infeasible and undesirable so lutions. Second, dynamic programming is used to solve the optimal static un it commitment problem for a given plant loading, feasible unit combinations , and current hydraulic conditions. Third, the DUCL problem is formulated a nd solved as a large-scale network problem with side constraints. Output fr om the model includes DUCL schedules, spinning and operating reserve, and t rades curves such as that between water usage and the number of unit switch es. The innovative use of the procedure allows the model to effectively sch edule hydro units for the energy and capacity markets in real-time. Applica tion of the method is demonstrated by determining the 24-time-step DUCL sch edule for a 2700 MW plant with ten units of four different unit types.