Siemens 7SR12 Argus - Page 380

7SR11 & 7SR12 Applications Guide
Page 24 of 48 ©2017 Siemens Protection Devices Limited
I
RES
V
RES
I
RES
Cos
θ
I
RES
Sin
θ
θ
Figure 2.8-5 Cosine component of current
(iii) Application of a Wattmetric power characteristic. The directional 50/51 SEF element operation is subject to an
additional sensitive residual power element which operates only on the real (wattmetric) component of residual
power.