Electrical appliance which can be supplied by an AC power network comprising: - means for detecting the network phase voltage values, - evaluation means for receiving the network phase voltage values detected by the means, and - bandpass filter means for receiving the network phase voltage values detected by the means, the bandpass filter means having a centre frequency, characterised in that - the electrical appliance is an apparatus with regenerative supply unit, the supply unit being connected to the supplying electrical network via at least one inductor and the network phase voltage being detected on the network side by the inductor, - the electrical appliance further comprises: determination means for determining a voltage space vector from the detected network phase voltage values, which can be represented as a complex vector, the determination means being connected on the output side to the evaluation means in such a manner that real part and imaginary part of this vector are supplied as voltage values to the evaluation means, and the determination means being connected on the output side also to the Bandpass filter means in such a manner that real part and imaginary part of this vector are supplied as voltage values also to a respective bandpass filter means and the output signals of the bandpass filter means are likewise supplied to the evaluation means, - the bandpass filter means has a controllable centre frequency, and - comparison means for comparing the output signals of the bandpass filter or the bandpass filters with a component of the voltage space vector, with the real part or imaginary part, are provided, - the comparison means being connected to the determination means for determining a deviation which is supplied to a regulator, the control variable of which is the centre frequency of the bandpass filter or the bandpass filters. - means for detecting the network phase voltage values, - evaluation means for receiving the network phase voltage values detected by the means, and - bandpass filter means for receiving the network phase voltage values detected by the means, the bandpass filter means having a centre frequency, - the electrical appliance is an apparatus with regenerative supply unit, the supply unit being connected to the supplying electrical network via at least one inductor and the network phase voltage being detected on the network side by the inductor, - the electrical appliance further comprises: determination means for determining a voltage space vector from the detected network phase voltage values, which can be represented as a complex vector, the determination means being connected on the output side to the evaluation means in such a manner that real part and imaginary part of this vector are supplied as voltage values to the evaluation means, and the determination means being connected on the output side also to the Bandpass filter means in such a manner that real part and imaginary part of this vector are supplied as voltage values also to a respective bandpass filter means and the output signals of the bandpass filter means are likewise supplied to the evaluation means, determination means for determining a voltage space vector from the detected network phase voltage values, which can be represented as a complex vector, the determination means being connected on the output side to the evaluation means in such a manner that real part and imaginary part of this vector are supplied as voltage values to the evaluation means, and the determination means being connected on the output side also to the Bandpass filter means in such a manner that real part and imaginary part of this vector are supplied as voltage values also to a respective bandpass filter means and the output signals of the bandpass filter means are likewise supplied to the evaluation means, - the bandpass filter means has a controllable centre frequency, and - comparison means for comparing the output signals of the bandpass filter or the bandpass filters with a component of the voltage space vector, with the real part or imaginary part, are provided, - the comparison means being connected to the determination means for determining a deviation which is supplied to a regulator, the control variable of which is the centre frequency of the bandpass filter or the bandpass filters.