Wind turbine with integrated battery storage

A method of controlling the flow of current to and from a battery storage electrically connected to a converter of an energy generator, wherein the energy generator is generating an electric current, the electric current is conducted to an electric grid via an electric flow path through the power converter,

• the battery storage is electrically connected to the electric flow path,
• the battery storage comprises a plurality of battery cells, each battery cell comprises at least one battery element and four semiconductor switches,
• wherein a controller is controlling the voltage over the battery storage by controlling the status of each of the four semiconductor switches, and thereby controlling a current path through the plurality of battery cells and
• wherein the controller is furthermore controlling the polarity of the current in the point of connection of the battery cell to the current path and thereby establishing the AC voltage or DC voltage that is required from the battery storage at a given time.

A battery storage electrically connected to the electric flow path of an energy system comprising an energy generator and a load, the battery storage comprising a plurality of battery cells, each battery cell comprising at least one battery element and four semiconductor switches,

• wherein a controller is configured for controlling the voltage over the battery storage by controlling the status of the four semiconductor switches of a plurality of the battery cells and thereby if a current path through the battery storage is selectively:
• bypassing the at least one battery element of one or more the plurality of battery cells or
• passing through the at least one battery element of one or more of the plurality of battery cells
• wherein the control of the four semiconductor switches of a battery cell facilitates changing polarity of the current in the point of connection of the battery cell to the current path, thereby facilitates connecting the current path of the battery storage to both an AC or a DC part of the electric system and thereby facilitates establishing the AC voltage or DC voltage that is required from the battery storage at a given time.