METHOD OF DETERMINING FREQUENCIES OF TERMS OF ELECTRIC QUANTITY OF ASYNCHRONOUS MODE Russian patent published in 2024 - IPC G06F17/14 H01H83/22 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, namely to relay protection and automation. According to the method, an electrical quantity is converted into a digital signal, the adaptive filter is adjusted for complete suppression of the digital signal, and estimates of the frequencies of the digital signal components are determined from the roots of the characteristic equation of the filter in the unit for determining frequencies. Adaptive filter is performed with intra-model decimation of digital signal samples with an adjustable decimation step. For this purpose, in the asynchronous mode frequency detection unit, from the set of digital signal frequency estimates, frequency estimates belonging to the range of a given value with centre at the point corresponding to the nominal frequency are selected. In the slip frequency unit, a slip frequency signal is generated, which is proportional to the difference of these frequency estimates. In the decimation adjustment circuit, the slip frequency signal level is controlled by a frequency comparator, and the decimation step is set for the next stage of the adaptive filter adjustment. When the comparator is actuated, the decimation step is taken to be equal to the specified value, and otherwise – to the value at the output of the decimation step determiner.

EFFECT: high resolution of the method when determining the frequencies of the terms of the electrical value of the asynchronous mode.

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