Method and device for the treatment of fault currents in a high-voltage battery connected to a charging station via a charging circuit

A method for the treatment of fault currents in a high-voltage battery connected to a charging station via a charging circuit, in particular in a motor vehicle, comprising the steps:

• providing the high-voltage battery, with a nominal battery voltage present between a first high-voltage potential on a battery side and a second high-voltage potential on the battery side;
• providing the charging circuit;
• providing the charging station, with a nominal charging voltage, which is smaller than the nominal battery voltage, present between a first high-voltage potential on a charging station side and a second high-voltage potential on the charging station side,
• establishing an electric protective-conductor connection between a protective conductor on the charging station side and a protective conductor on the battery side, which is electrically insulated, in a non-fault condition, with respect to the first high-voltage potential on the battery side and the second high-voltage potential on the battery side, in order to connect the protective conductor on the battery side via the protective conductor on the charging station side to a ground potential on the charging station side;
• establishing one electric charging connection, respectively, of the first high-voltage potential on the charging station side to the first high-voltage potential on the battery side and of the second high-voltage potential on the charging station side to a second high-voltage potential on the battery side via the charging circuit, in order to apply to the high-voltage battery, in an optional charging step, a charging voltage, which is higher than the nominal charging voltage of the charging station and has been boost-converted by a boost converter belonging to the charging circuit, in order to transmit electrical energy from the charging station into the high-voltage battery;
• occurrence of a fault condition, in which, by a low-resistance connection of the first high-voltage potential on the battery side or of the second high-voltage potential on the battery side to the protective conductor on the battery side, a fault current circuit forms via the charging station and the protective-conductor connection, with a fault current supplied from the high-voltage battery;
• reducing the fault current during the fault condition, by a fault current controller belonging to the charging circuit, to a reduced fault current, the reduced fault current being greater than zero but less than the fault current.