Method and system for a safety concept for an AC battery

A system for a safety concept, the system comprising:

• a traction machine;
• an AC battery connected to the traction machine, the AC battery comprising a central controller, a plurality of battery modules which are arranged in at least one string and respectively have a power board with a plurality of switching states, a plurality of contactors, a plurality of current sensors, a fault loop and a high-speed bus,
• wherein the central controller has a hardware-programmable processor unit with at least one microprocessor core on which a control program is configured to control the battery modules, the plurality of contactors and the fault loop,
• wherein a state machine is implemented by the control program,
• wherein the battery modules are connected, starting from the central controller, via the high-speed bus and the fault loop,
• wherein, if an abort fault is detected, the central controller is configured to change the AC battery to a safe operating state by:
• requesting each battery module via the high-speed bus to assume a bypass switching state,
• ordering a respective safety switching position in each contactor, and
• finally disconnecting the central controller from the fault loop, the high-speed bus, and the plurality of battery modules.