Method for preventing a dangerous higher-frequency earth fault current for an electrical drive system which is operated in an electrical grid and has a power converter and an electrical drive machine, wherein - in a first method step, a common-mode voltage is produced in the power converter, said common-mode voltage having a defined common-mode voltage component (UCMA) at a selected low frequency, wherein the higher frequency of the dangerous earth fault current is greater than 1 kHz and the selected low frequency of the defined common-mode voltage component (UCMA) of the common-mode voltage is less than 1 kHz, wherein the common-mode voltage is sensed by means of voltage sensing in a direct voltage intermediate circuit as one of several current circuits of the power converter or at a load-side power converter output as another of several current circuits of the power converter, and wherein the defined common-mode voltage component (UCMA) of the common-mode voltage at the selected low frequency is determined by a voltage evaluation, - in a second method step, in the event of an earth fault in the electrical drive system, a common-mode current component (ICMA) of a common-mode current flows through a predominantly ohmic conductor-earth impedance at the selected low frequency on the basis of the defined common-mode voltage component (UCMA), - in a third method step, a total current of the common-mode current is sensed by means of current sensing in one of several current circuits of the electrical drive system, - in a fourth method step, the common-mode current component (ICMA) of the common-mode current at the selected low frequency is determined from the total current by means of a current evaluation and - in a fifth method step, the electrical drive system is disconnected from the electrical grid by means of an electrical switching element if the common-mode current component (ICMA) of the common-mode current at the selected low frequency reaches a reference value. - in a first method step, a common-mode voltage is produced in the power converter, said common-mode voltage having a defined common-mode voltage component (UCMA) at a selected low frequency, wherein the higher frequency of the dangerous earth fault current is greater than 1 kHz and the selected low frequency of the defined common-mode voltage component (UCMA) of the common-mode voltage is less than 1 kHz, wherein the common-mode voltage is sensed by means of voltage sensing in a direct voltage intermediate circuit as one of several current circuits of the power converter or at a load-side power converter output as another of several current circuits of the power converter, and wherein the defined common-mode voltage component (UCMA) of the common-mode voltage at the selected low frequency is determined by a voltage evaluation, - in a second method step, in the event of an earth fault in the electrical drive system, a common-mode current component (ICMA) of a common-mode current flows through a predominantly ohmic conductor-earth impedance at the selected low frequency on the basis of the defined common-mode voltage component (UCMA), - in a third method step, a total current of the common-mode current is sensed by means of current sensing in one of several current circuits of the electrical drive system, - in a fourth method step, the common-mode current component (ICMA) of the common-mode current at the selected low frequency is determined from the total current by means of a current evaluation and - in a fifth method step, the electrical drive system is disconnected from the electrical grid by means of an electrical switching element if the common-mode current component (ICMA) of the common-mode current at the selected low frequency reaches a reference value.