ABB 615 Series - Page 432

voltage
V
3H RES_
. This is the recommended option for calculating the terminal side
third harmonic voltage.
V V
3 3H T H RES_ _
=
GUID-FA9E6643-E455-45F6-8CF7-E227FA184B9A V1 EN (Equation 44)
• Voltage selection setting is set to "Calculated V0" if all three phase-to-ground
voltages are available. In this case, the terminal side third harmonic voltage is
calculated as a vector average of the third harmonic voltage of all three phases.
V V V V
3 3 3 3
1
3
H T H A H B H C_ _ _ _
= ⋅ + +
( )
GUID-BE0AAF09-4061-4E1F-AF03-16693214E14F V1 EN (Equation 45)
• If only one phase-to-ground voltage is available, the Voltage selection setting is set to
the respective phase, that is, "Phase A" or "Phase B" or "Phase C" based on the
available phase. In this case, the magnitude of the terminal side third harmonic
voltage is assumed to be equal to the third harmonic voltage of the phase available.
V V or V or V
3 3 3 3H T H A H B H C_ _ _ _
=
GUID-EC492C5F-586D-465F-A591-CEEB5095C6CE V1 EN (Equation 46)
The function is internally blocked if the magnitude of calculated
V
3H T_
is lower than the
set Voltage block value, this also activates the INT_BLKD output.
Differential calculation
The amplitude of the third harmonic differential voltage can be calculated using the
following equation.
VD
H
H T H N
3
3 3
= V V
_ _
+
GUID-DAB7253C-E06A-4D3A-84B1-8FA66DF15920 V1 EN (Equation 47)
VD
3H
Magnitude of the third harmonic differential voltage
V
3H T_
Terminal side third harmonic voltage phasor
V
3H N_
Neutral side third harmonic voltage phasor
The magnitude of the third harmonic differential voltage UD_3H and the phase angle
difference between the terminal side and neutral side third harmonic voltage
U_3HANGL_T_N are available in the Monitored data view.
Section 4 1MAC059074-MB A
Protection functions
426 615 series ANSI
Technical Manual