Sizing control reserves with a new dynamic method considering wind and photovoltaic power forecasts

Control reserves are usually sized statically which means there is a fixed amount of reserves for a long period. In reality the demand for frequency control fluctuates strongly. For this reason a dynamic method for the sizing of control reserves for the following day should be developed that could be used in Germany already today. In this paper all possible imbalances are classified. Afterwards the influences on the probability density functions of the different classes of imbalances are analysed. The identified factors will be the base for the new sizing method as they are crucial for the demand for frequency control. Additionally the stochastic independence of forecast errors and fluctuations around this forecast error is examined which is a prerequisite for the convolution of two probability density functions which will be preferably used for the new method.