Wind turbine with integrated battery storage

A method of controlling an electric flow path to and from a battery storage, the method comprising steps of:

• conducting an electric current to an electric grid via the electric flow path;
• electrically connecting the battery storage to the electric flow path, the battery storage including a plurality of battery cells, and each battery cell including a battery element and four semiconductor switches,
• controlling a voltage over the battery storage by controlling a status of the respective four semiconductor switches of multiple respective battery cells of the plurality of the battery cells,
• wherein the step of controlling the voltage over the battery storage includes controlling:
• a current path to bypass at least one respective battery element of one or more of the multiple respective battery cells, or
• the current path to pass through the at least one respective battery element of one or more of the multiple respective battery cells, and
• wherein the step of controlling the voltage over the battery storage facilitates:
• changing polarity of the electric current in a point of connection of the multiple respective battery cells to the current path, the current path of the battery storage being connectable to both of an AC or a DC part of the electric flow path,
• wherein the controller is controlling the voltage over the battery storage by a combination of different battery cells, and
• wherein the combination is established by a state of charge evaluation of the battery cells.

A battery storage system comprising:

• a battery storage electrically connected to an electric flow path, the battery storage including a plurality of battery cells, each battery cell including at least one battery element and four semiconductor switches;
• and
• a controller configured to control a voltage over the battery storage by controlling a status of the respective four semiconductor switches of multiple respective battery cells of the plurality of the battery cells, whereby:
• a current path is controlled to bypass at least one respective battery element of one or more of the multiple respective battery cells, or
• the current path is controlled to pass through the at least one respective battery element of the one or more of the multiple respective battery cells,
• wherein the control of the respective four semiconductor switches of the multiple respective battery cells facilitates:
• changing polarity of the electric current in a point of connection of the multiple respective battery cells to the current path, the current path of the battery storage being connectable to both of an AC or a DC part of the electric flow path,
• wherein the controller is configured to control of the voltage over the battery storage by a combination of different battery cells, and
• wherein the combination is established by a state of charge evaluation of the battery cells.