Abstract: A method identifies asymmetrical vibrations during the operation of an electric device which is connected to a high-voltage grid. Vibrations of the electric device are detected using vibration sensors which provide measured values on the output side. The measured values and/or values derived from the measured values are transmitted to a communication unit via a close-range communication connection. The measured values and/or the values are transmitted by the communication unit to a data processing cloud via a far-range communication connection. The measured values are separated into frequency components by the data processing cloud using a Fourier transformation, thereby obtaining a frequency spectrum. Odd and even frequency components of the frequency spectrum are ascertained based on a base frequency of the high-voltage supply grid and put into a ratio R relative to one another. The presence of asymmetrical vibrations is indicated if the ratio R exceeds a specified threshold.

Abstract: A method for identifying asymmetrical vibrations during the operation of an electric device which is connected to a high-voltage grid: Operational noise of the electric device is detected using acoustic sensors which output measured values. The measured values and/or values derived therefrom are transmitted to a communication unit via a close-range communication connection and then transmitted to a data processing cloud via a far-range communication connection. The measured values and/or the values derived from the measured values are separated into frequency components by the data processing cloud using a Fourier transformation, thereby obtaining a frequency spectrum. Odd and even frequency components of the frequency spectrum are ascertained on the basis of a base frequency of the high-voltage supply grid and put into a ratio R relative to one another. The presence of asymmetrical vibrations is indicated if the ratio R exceeds a specified threshold.

Abstract: A method for determining a direct current component in an electric device that is connected to a high-voltage supply network. The method includes the following steps: acquiring operating noises of the electric device with the aid of acoustic sensors that are part of a portable unit and that provide acoustic signals at the output; breaking the acoustic signals down into their frequency components by a Fourier transformation, yielding a frequency spectrum; determining odd and even frequency components of the frequency spectrum in dependence upon a basic frequency of the high-voltage supply network and setting them in a ratio to one another; concluding that a direct current component is present if the ratio exceeds a predefined threshold value.