Modeling and static optimization of a variable speed pumped storage power plant

Pumped storage power plants are key components to stabilize electric distribution networks with high amount of intermittent power sources as, e.g., solar and wind power plants. Tailored mathematical models are important for the transient and the stationary analysis of such plants. A comprehensive mathematical model of a variable speed operated pumped storage power plant, which incorporates reversible pump turbines in combination with doubly fed induction machines, is developed in this paper. Special emphasis is laid on an accurate description of important dynamic effects (e.g., water hammer) and of the energy losses of the system. Based on this model, optimal stationary operating points are determined, which minimize the overall system losses and systematically take into account the operating constraints.