Security concept for integrating a battery into an inverter

An inverter apparatus comprising:

• a DC voltage link,
• an input stage coupled to the DC voltage link and configured to receive DC electric power from a DC power generator for loading the DC voltage link,
• a DC/AC converter coupled to the DC voltage link and configured to feed AC electric power into a power grid,
• a bidirectional connection configured to couple a battery to the DC voltage link (6), to load the battery out of the DC voltage link in a first direction, and to load the DC voltage link out of the battery in a second, opposite direction, and
• a controller configured to operate the DC/AC converter and, dependent on present values of relevant parameters of the battery, to selectively operate the bidirectional connection in the first direction or the second direction,
• wherein the controller is coupled to an interface configured to receive the present values of the relevant parameters of the battery from a battery monitoring unit associated with the battery,
• wherein the relevant parameters of the battery issued by the battery monitoring unit and received by the interface include working data related to at least a state of charge of the battery and safety data indicating a safety state of the battery,
• wherein the controller is configured to consider the working data in operating the bidirectional connection,
• wherein the controller is configured to be commanded by the safety data (20) in operating the bidirectional connection,
• wherein the interface comprises separate interface units configured to receive the working data and the safety data, respectively, and
• wherein the controller is configured to receive the safety data as a safety signal that indicates a safety of the battery only when a signal level of the safety signal is within a predetermined safety level range and/or when a signal repetition frequency of the safety signal is within a predetermined safety frequency range.