Electrical devices are connected to a DC voltage power supply grid being connected to a power source and having a supply voltage. Protection devices protect the electrical devices against an unintentional overcurrent sensed by a sensor unit. The protection devices disconnect the electrical devices from the DC voltage power supply grid when an overcurrent is detected. A pulse circuit having a capacitor with a semiconductor switching element connected in series with the capacitor is connected to respective inputs of the protection devices and supplies an amount of electric charge when a voltage dip occurs, wherein the amount of supplied electric charge is determined based on the detected overcurrent and a predetermined time period.