Studies on Provision of Ancillary Services by Distributed Generation Units and Storage Devices

The structure of current power systems successively changes due to an increasing share of distributed generation units. So far, electricity is mainly produced by central power plants providing all ancillary services, e.g. voltage stability, frequency control and black-start capability. During the last decades the world-wide installed capacity of renewable energy resources has multiplied due to the targeted reduction of carbon dioxide emissions. Another driving force behind the ongoing decentralization is the grown demand of customers to produce electricity and heat locally. A central control of these distributed units can generate synergies and increase their relevance for system control. This investigation examines the provision of primary control power and reactive power control by a pool of distributed generation units and energy storage systems. It has been shown that due to the small activation times the provision of primary control power can be significantly faster than it is required by the regulatory framework. Furthermore, the reactive power demand of customers can be covered optimally resulting in minimized electrical losses.