Measurement Modes; Application - ABB 615 series Technical Manual

Section 4
Protection functions
4.2.6.6
4.2.6.7
418
k P *
ref
t s [ ]
=
P
cal
GUID-FEA556F2-175E-4BDD-BD0F-52E9F5499CA8 V3 EN
t[s] operation time in seconds
k set value of
P set value of
ref
P calculated residual power
cal
GUID-D2ABEA2C-B0E3-4C60-8E70-404E7C62C5FC V1 EN
Figure 201: 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
ground faults especially in compensated networks. The protection uses the residual power
Time multiplier
Reference power
1MAC059074-MB A
(Equation 43)
set at 0.15 xPn
ref
615 series ANSI
Technical Manual