Abstract: A dangerous, higher-frequency (>1 kHz) earth fault current in an electrical drive system operated in an electrical grid and having a power converter and an electrical drive machine can be prevented by producing a common-mode voltage with a defined common-mode voltage component in the power converter at a selected low frequency (<1 kHz); in the event of an earth fault in the electrical drive system, flowing at the selected low frequency a common-mode current component of a common-mode current through a predominantly ohmic conductor-to-earth impedance on the basis of the defined common-mode voltage component; measuring a total common-mode current in one of several current circuits of the electrical drive system; determining from the total current the common-mode current component; and when the common-mode current component reaches a reference value, disconnecting the electrical drive system from the electrical grid.

Abstract: An insulating part for an electronic device includes a first metallized outer surface capable of cooling one or more electronic components disposed on the insulating part. The insulating part also includes one or more additional metallized outer surfaces, such as a set of cooling ribs, to provide improved cooling for the electronic components. These additional outer surfaces are coupled electrically and thermally to the first metallized outer surface, and to each other by recesses containing a heat transfer element, such as a metallization or a soldered connection. Thus, heat transferred to the first outer surface is further dissipated among the several additional cooling surfaces.