IMPACT OF INTERMITTENT POWER SUPPLY ON THE GERMAN POWER SYSTEM

Abstract

In Germany due to the continuous high expansion of the intermittent power supply capabilities of wind turbines and photovoltaic systems, the operational modes of ther-mal generation units will be influenced essentially until 2020 and beyond. The integration of this increasing share of intermitting generation while maintaining the present security level of supply confronts the existing power system with a big challenge. The fundamental problems are that the intermitting generation does not necessarily fit the power demand and is often located far away from the load centers. This results in physical limitations for integration of intermitting generation with regard to the existing infrastructure. Therefore it is has to be lined out that the acceleration time constant is reduced if some conventional power plant generators with masses are disconnected and replaced by the intermittent generators while the total nominal power value of the whole system remains constant. On the other hand more immediate acting acceleration power produced by the turbine-generator-systems of the conven-tional power plants will disappear because of shut down of these plants and related loss of inertia. With the reduction of inertia not only the frequency deviation after disturbances will increase substantially but also with more oscillation occurs and causes reduction of system stability. Therefore, different methods and tools to simu-late the power plant scheduling will be presented and illustrated und