A Power Sharing Methodology Considering Wavelet Transform in a Residential Prosumer with a Hybrid Storage System

Power systems have faced significant changes in recent years due to the integration of renewable energies in the power grid. Thanks to its multiple advantages, the so-called clean energies play an important role in the development of the electrical system, allowing the active participation of end users in energy markets. However, the intermittent nature of these sources has delayed their full integration into power systems; unless operated in conjunction with energy storage systems (e.g. batteries, ultracapacitors, etc.) to smooth out the generation and match the demand. This article presents a power sharing methodology for the exchange of energy between batteries and ultracapacitors in a photovoltaic installation. The case study comprises a hybrid energy storage system, on-site generation and a residential user, where both the load and generation profiles are analyzed using wavelet transform. The high- and low-frequency components of both profiles are used to calculate the energy that is injected into the energy storage system. Results show that by separating the components of the signal in high and low frequencies it is possible to take advantage of the characteristics of each storage technology, extending its life cycle.