Hydro Power Equivalents of Complex River Systems

When a hydro power producer wants to plan the production for the next day in an optimal way a precise and detailed model is needed. But when using this model to plan for a longer period of time the computational complexity increases. To overcome this problem there is a need to do a model reduction of the original system into a smaller equivalent system with almost the same properties. This paper compares the performance and computation time of different setups in the equivalent representation of the original hydro power system. This includes different setups in both topology and the piecewise linear production equivalents. It is tested independently on two rivers with 21 and 28 stations respectively and also for the case if both of these rivers were to represented by one equivalent system. The performance is evaluated with respect to error in production and computation time. It is shown that with model reduction the relative error lies between 11.5 and 5.1 percent of installed capacity and the computation time is then reduced by 99.3 and 92.5 percent respectively.