Section 13 System protection and control13.1 Multipurpose filter SMAIHPAC13.1.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberMultipurpose filter SMAIHPAC - -13.1.2 ApplicationThe multi-purpose filter, function block with name SMAI HPAC, is arranged as a three-phase filter. It has very much the same user interface (e.g. function block outputs) as thestandard pre-processing function block SMAI. However the main difference is that it canbe used to extract any frequency component from the input signal. For all four analogueinput signals into this filter (i.e. three phases and the residual quantity) the input samplesfrom the TRM module, which are coming at rate of 20 samples per fundamental systemcycle, are first stored. When enough samples are available in the internal memory, thephasor values at set frequency defined by the setting parameter SetFrequency arecalculated. The following values are internally available for each of the calculatedphasors:• Magnitude• Phase angle• Exact frequency of the extracted signalThe SMAI HPAC filter is always used in conjunction with some other protection function(e.g. multi-purpose protection function or overcurrent function or over-voltage functionor over-power function). In this way many different protection applications can bearranged. For example the following protection, monitoring or measurement features canbe realized:1MRK 506 369-UUS - Section 13System protection and controlLine distance protection REL670 2.2 ANSI 617Application manual
