ABB Relion 670 Series Commissioning Manual page 194

Section 11
Testing functionality by secondary injection
The set operate value in secondary amperes is calculated according to the following
equations:
First part of the characteristic (Restrain voltage ≤ 25% of
StartCurr
IECEQUATION2432 V1 EN-US
Second part of the characteristic (25% of
100*







 

IECEQUATION2433 V1 EN-US
Third part of the characteristic (
StartCurr
IECEQUATION2434 V1 EN-US
Example (rated secondary current = 1A):
CT ratio
VT ratio
StartCurr
VDepFact
UHighLimit
IBase
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
0,25*
lower than
•
•
•
Second section of the characteristic only:
If
0,25*
•
•
•
Last section of the characteristic:
If
higher than
188
In the following equations, restrain voltage is the magnitude of the
minimum phase-to-phase voltage in secondary volts.
CT sec
IBase
× × ×
100
CTprim
UBase ), valid when setting parameter VDepMode = Slope :


StartCurr CT sec VDepFact
× ×  × −
1
IBase 

100 CTprim  100
( )
−
UH i i ghLimit 25
VT sec
× ×
UBase
100
VTprim
CT sec
IBase
× ×
100 CTprim
VDepMode = Slope , the minimum measured phase-to-phase voltage is lower than
UBase ; if VDepMode = Step , the minimum measured phase-to-phase voltage is
UHighLimit /100* UBase :
UL1: Ampl = 10 / √3; Angle = 0°
UL2: Ampl = 10 / √3; Angle = 240°
UL3: Ampl = 100 / √3; Angle = 120°
VDepMode = Slope , the minimum measured phase-to-phase voltage is between
UBase and UHighLimit /100* UBase :
UL1: Ampl = 50 / √3; Angle = 0°
UL2: Ampl = 50 / √3; Angle = 240°
UL3: Ampl = 100 / √3; Angle = 120°
VDepMode = either Slope or Step , the minimum measured phase-to-phase voltage is
UHighLimit /100* UBase :
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VDepFact
100
UBase ≤ Restrain voltage ≤ UHighLimit /




25
× − ×
 Re strainVoltage U U Base
 100
UHighLimit /100* UBase ≤ Restrain voltage):
10 000/1A
10 kV/100 V
100%
25%
100%
10 000 A
10 kV
UBase ):


 
VT sec StartCurr C C T sec

× + × ×
  IBase

VTprim   100 CTprim
 

Transformer protection RET670
Commissioning manual
1MRK 504 165-UEN E
(Equation 95)

VDepFact
×

100 
(Equation 96)
(Equation 97)