Analysis of ancillary services within smart grid framework

As a result of the changes that occur in the electrical distribution networks, there is guidance tendency toward users, not only to power systems. This is a feature of the smart grid that will ensure safety operational and power quality, and also facilitates network connection of renewable source. Smart grid can intelligently integrate the behavior of all users connected to this network - electricity producers, users and prosumers, in order to ensure efficient delivery, sustainable, economically and with security conditions of electricity. The power balance and ancillary services provided by the storage systems in distribution network represent two aspects of one problem that must be treated properly, with in an appropriate manner, taking into account the parameters of typical distribution network. Current limits of energy storage force production to correspond to the energy used in any moment. Using storage systems is a necessity for the power system, considering the current tendency to grow of renewable sources penetration, the requirements for reliability and power quality improvement and also the implementation of smart grid. Storage systems have an important role in increasing the system efficiency and ensuring stable operation of the system by contributing to secondary and fast tertiary control. In the first section, a general analysis was performed, in order to identify the current state-of-art of energy storage systems. An example was designed, starting from a real electric distribution system, in order to create an arrangement of possible issues and solutions for electricity storage systems which provide ancillary services.