Woodward HighPROTEC - Page 818

Protective Elements
Type of impedance characteristic: The impedance characteristic of a distance protection element is an operating
characteristic; this means the distance element shall operate if the measured impedances are inside the
characteristic boundary. There are two types of characteristic available, settable via the parameter »Type of imp.
area« : “MHO” (circle), or “Polygon”.
• MHO (circle):
The MHO characteristic can be defined with four settings (see next diagram). Note that the center of the
MHO circle is defined as the point half-way between the »Mho Pos.Imp.Reach« vector and the »Mho
Offs.Imp.Reach« vector. Both vectors are configured by setting their magnitude (“length”) and angle with
the R-axis.
Operating area (colored in bright red) of type MHO (circle), with »Direction enable« = “inactive”.
Operating area (colored in bright red) of type MHO (circle), with »Direction enable« = “active”.
818 MCDGV4 DOK-HB-MCDGV4-2E
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