Energy storage possibilities in consideration of distribution networks
Distribution power grids will basically change in the near future: the increasing penetration of renewable energy sources causes high amount of intermittent and decentralized generation. This procedure will lead to problems which are unknown for a conventionally planned and operated grid. Bidirectional power flows, power quality issues and voltage sags can occur.
Energy storage systems are able to play a key role in the solutions. With a well-developed controlling strategy, these applications could support the low voltage grids locally: virtual islanding operations and load following, or improved reliability with reserves are all feasible. These installations can even be used for trading on the liberalized electricity market.
The focus of this work is to provide useful information and a proper approach for evaluating the possibilities of the integration of storage systems as a network development. The simulation script - which has been implemented in the DigSilent Power Factory program - considerate the main parameters of an ESS: efficiency, capacity, response time, and cycle lifetime in optional time steps through load flow simulations. If a grid model meets a few requirements, it can be used as an input for the simulation script (demonstration topology is attached in the appendix). Wide range of technical data inputs and possible applications are also provided. The functioning is demonstrated with self-developed strategies. The technical and economic effects of the installations is evaluated with some simple calculations. With further standardizing, this concept could be a useful tool for the distribution system operators and network developers.