Control concept with limit management for DC / DC converters in a power system

The invention relates to an apparatus for controlling a power system having at least one power unit and at least one DC / DC converter, wherein the DC / DC converter having at least one electrical component is coupled, and a power supply to the electrical component by the DC / DC converter is variable, wherein the maximum deliverable power is determined on the electrical component by a power limit value of the DC / DC converter. According to the invention it is provided that the power unit and the DC / DC converter and the electric component are coupled via a limit management system that regulates the power output so that a power output at a power demand of the electrical component via the power limit value of the DC / DC converter to a maximum of the power limit value is.