Measurement Modes - ABB RELION Series Technical Manual

Section 4
Protection functions
4.2.6.6
4.2.6.7
368
GUID-D2ABEA2C-B0E3-4C60-8E70-404E7C62C5FC V1 EN
Figure 192: Operation time curves for wattmetric IDMT for S

Measurement modes

The function operates on three alternative measurement modes: "RMS", "DFT" and
"Peak-to-Peak". The measurement mode is selected with the Measurement mode
setting.
Application
The wattmetric method is one of the commonly used directional methods for detecting
the earth faults especially in compensated networks. The protection uses the residual
power component 3UoIoCosφ (φ is the angle between the polarizing quantity and
operating quantity compensated with a relay characteristic angle).
1MRS758755 A
set at 0.15 xPn
ref
REC615 and RER615
Technical Manual