StartCurr
IBase
CT
CTprim
VDepFact
100
100
×
×
×
sec
IECEQUATION2432 V1 EN-US
(Equation 89)
Second part of the characteristic (25% of
UBase ≤ Restrain voltage ≤ UHighLimit/
100*
UBase), valid when setting parameter VDepMode = Slope:
StartCurr
IBase
CT
CTprim
VDepFact
UH
100
1
100
×
×
×
−
sec
iighLimit
UBase
VT
VTprim
strainVoltage
−
(
)
×
×
×
−
×
25
100
25
100
sec
Re
U
UBase
VT
VTprim
StartCurr
IBase
×
+
×
×
sec
100
C
CT
CTprim
VDepFact
sec
×
100
IECEQUATION2433 V1 EN-US
(Equation 90)
Third part of the characteristic (
UHighLimit/100*UBase ≤ Restrain voltage):
StartCurr
IBase
CT
CTprim
100
×
×
sec
IECEQUATION2434 V1 EN-US
(Equation 91)
Example (rated secondary current = 1A):
CT ratio
10 000/1A
VT ratio
10 kV/100 V
StartCurr
100%
VDepFact
25%
UHighLimit
100%
IBase
10 000 A
10 kV
A test for each section of the characteristic of the function VRPVOC may be performed;
that may be achieved by applying the following voltages:
First section of the characteristic:
If
VDepMode = Slope, the minimum measured phase-to-phase voltage is lower than
0,25*
UBase; if VDepMode = Step, the minimum measured phase-to-phase voltage is
lower than
UHighLimit/100*UBase:
•
UL1: Ampl = 10 / √3; Angle = 0°
•
UL2: Ampl = 10 / √3; Angle = 240°
•
UL3: Ampl = 100 / √3; Angle = 120°
Second section of the characteristic only:
If
VDepMode = Slope, the minimum measured phase-to-phase voltage is between
0,25*
UBase and UHighLimit/100*UBase:
•
UL1: Ampl = 50 / √3; Angle = 0°
•
UL2: Ampl = 50 / √3; Angle = 240°
•
UL3: Ampl = 100 / √3; Angle = 120°
Last section of the characteristic:
If
VDepMode = either Slope or Step, the minimum measured phase-to-phase voltage is
higher than
UHighLimit/100*UBase:
•
UL1: Ampl = 105/ √3; Angle = 0°
•
UL2: Ampl = 105/ √3; Angle = 240°
•
UL3: Ampl = 105 / √3; Angle = 120°
4.
Inject the voltages that are related to the first part of the characteristic, and then slowly
increase the phase current IL1 from 0.0 A up to the value the function operates. The
START and STOC signals must be activated when the amplitude of the phase current IL1
1MRK 502 067-UEN B
Section 12
Testing functionality by secondary injection
179
Commissioning manual
