On the physical system modelling of energy storages as equivalent circuits with parameter description for variable load demand (Part I)

•A general modeling approach for various energy storages including non-linear effects of analyzed storages is proposed.•The dynamic behavior of energy storages is measured by circuit elements and its accuracy by the implemented elements.•Energy storage's dynamic response can be tested with any variable load profile.•The proposed method allows the analysis of energy storages; existing and novel storages for fast and easier assessment.

Energy storages take a key role in electrical energy balancing in our power grid in respect to the increasing utilization of renewable energies. Assessing the effectiveness of energy storages and finding the optimal use under varying load conditions is essential which requires accurate modelling. This study highlights the equivalent circuit modelling approach for different energy storages. The model parameters R, L, C and Ub define the storage system in question allowing us to analyse storage devices under varying load conditions. Technical assessment criteria (efficiency, response time etc.) of energy storages can also be deducted from these models. Energy storages feature non-linear characteristics which are reflected in variable model parameters.