ABB 615 series Technical Manual page 448

Section 4
Protection functions
442
Y ( ) t Y ( ) t
=
osum CPS _ osum
1 1
GUID-EDC80710-FA5D-4966-AE81-888E8B4D2CD5 V1 EN
Y ( ) t Y ( ) t
=
osum CPS _ osum
2 1
GUID-696EFC44-7AF4-45A9-A3F4-11C153143D55 V1 EN
( ) ( )
Y t Y t
=
osum CPS _ osum
3 1
GUID-A18538B4-EFCD-4844-AEFB-0BB92358582A V1 EN
Y ( ) t Y ( ) t
=
osum CPS _ osum
4 1
GUID-EBDE2421-0F49-4141-87E2-433DF64503C9 V1 EN
Y ( ) t Y ( ) t
=
osum CPS _ osum
5 1
GUID-8E0FAAAB-F656-4FCF-AC71-42C357E77F3E V1 EN
GUID-69E030E7-F3CF-4872-AF6A-3D12002EA3AC V1 EN
Figure 212: Principle of Cumulative Phasor Summing (CPS)
The CPS technique provides a stable directional phasor quantity despite individual
phasors varying in magnitude and phase angle in time due to a non-stable fault type such
as restriking or intermittent ground fault. This is also true for harmonic components
included in the sum admittance phasor. Harmonics have typically a highly fluctuating
character.
Harmonic components provide a more distinctive directional determination in
compensated networks than the fundamental frequency component. The higher the
frequencies, the compensation coil appears as very high impedance and the harmonics are
not affected by compensation coil and degree of compensation. When harmonics are
Y ( ) t
+
osum
2
( ) ( )
Y t Y t
+ +
osum osum
2 3
Y ( ) t Y ( ) t
+ + +
osum osum
2 3
Y ( ) t Y ( ) t
+ + +
osum osum
2 3
1MAC059074-MB A
Y ( ) t
osum
4
Y ( ) t Y t ( )
+
osum osu m m
4 5
615 series ANSI
Technical Manual
(Equation 58)
(Equation 59)
(Equation 60)
(Equation 61)
(Equation 62)