Energy Storage Systems for Fluctuating Energy Sources and Fluctuating Loads—Analysis of Selected Cases

The dynamic development of energy storage technologies makes it possible to solve many problems related to the negative impact of renewable sources and fluctuating loads on the power and voltage quality parameters at their point of connection to the distribution grid. By absorbing temporary energy surpluses and covering temporary energy deficits, these technologies enable the smoothing of output power profiles of wind turbines, as well as the reduction in peak power values, for example, in traction substations or fast-charging hubs for electric vehicles. This article discusses the specifics of both applications with particular emphasis on methods for sizing energy storage parameters, methods for their control, and the special effects they allow us to achieve. The methods proposed by the authors allow for the more optimal selection of energy storage parameters in existing energy facilities based on their measured power profiles. The proposed control methods, in turn, allow for not only a reduction in relative changes in power and voltage but also enable an increase in the installed power of wind farms without investing in the modernization of the distribution network, as well as reducing the contracted power of traction substations. The analyses presented in this article are based on power profile measurements of real objects, and the proposed solutions are already being implemented in power infrastructure.