Patent ID: 10024928

Abstract:
The disclosure relates to a detection method for an inverter for detecting a grid fault in a power supply grid, includes determining a grid impedance (Z) and/or the rate of change thereof with respect to time (dZ/dt) and/or a rate of change of an absolute value of the grid impedance (Z) with respect to time (d|Z|/dt), comparing the absolute value and/or a real part and/or an imaginary part of the grid impedance (Z) and/or the rate of change thereof with respect to time (dZ/dt) and/or the rate of change of the absolute value of the grid impedance (Z) with respect to time (d|Z|/dt) with respective predetermined limit values. The method also includes detecting a grid fault state based on the comparison, wherein a distinction is drawn between an islanding situation (AID) and a fault ride through (FRT) situation, and signaling an existing islanding situation (AID) or a fault ride through (FRT) situation as a grid fault state. The disclosure additionally relates to an inverter that is arranged to perform the method.