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.