Provision of Ancillary Services by different Decentralized Energy Resources

Modern power systems frequently operate near to critical operating limits due to the shut-off of many conventional power plants caused by the integration of renewable energy sources in the grid. In the past, primary control was mainly provided by synchronous generators to stabilize the grid frequency in case of large disturbances. Due to the expansion of renewable energy sources, the system inertia and the provision of primary control will decrease. As a result, the frequency will become more sensitive in case of an imbalance between production and consumption of electric energy. To ensure a stable system operation in future networks, Renewable Energy Sources (RES) must provide frequency containment reserve. However, the different control schemes of the Distributed Energy Resource (DER) may cause mutual interferences which may lead to dynamic instabilities. Therefore, it is important to not only analyse one type of DER in a simulation model but to research the interplay of different technologies and control schemes. In this paper, four DER, namely Battery Energy Storage System (BESS), Photovoltaic (PV), Wind Power, and Combined Heat and Power (CHP) plant, are modelled and validated in a simplified test system to analyse the interactions between the frequency control algorithms and recommendations for the parameterisation of such controllers are given.