Method and arrangement for determining the total leakage impedance in an unearthed AC network

摘要

In a method and means for determining the total leakage impedance and the therefrom derivable maximum conductor contact current of an ungrounded AC network that the mains leads flowing through AC measurement current in the operating state is fed, preferably imprinted, which has a constant dynamic phase shift relative to the mains supply in such a way that between network and soil results in a beat between the superposed measuring and mains AC voltage components with respect to the mains frequency sufficiently small beat frequency. By extracting and processing the beat of the relevant in this given Meßwechselspannungsanteil can be determined. Thus, it is possible to determine on the mains frequency to relating frequency dependent total leakage impedance thereof and the ligand dependent maximum conductor contact current very accurately, for example with a frequency deviation between the measurement frequency and frequency of only 2 Hertz.