| 摘要 |
A method for producing an oscillation signal which indicates oscillation in an electrical power supply system, in which measured values that characterize current and voltage at a measurement point in the electrical power supply system are detected and are converted to digital current and voltage vector measured values. Impedance values are calculated in the complex numerical domain from the current vector measured values and the voltage vector measured values. A curve profile formed by the impedance values is considered and, if appropriate, the oscillation signal is produced using characteristic properties of the curve profile. In order to provide a method in which an oscillation can be identified as reliably as possible, a first oscillation supposition signal is produced when the separation of the impedance values from an oscillation center point remains substantially the same and a second oscillation supposition signal is produced when the rate at which the impedance values approach the curve profile remains substantially the same. The oscillation signal is produced when both the first and the second oscillation supposition signal are present. A protective device or measurement instrument has a corresponding oscillation identification device.
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