ABB rec670 - Page 121

The set operate value in secondary amperes is calculated according to the
following equations:
First part of the characteristic (Restrain voltage ≤ 25% of UBase):
StartCurr
IBase
CT
CTprim
VDepFact
100 100
× × ×
sec
IECEQUATION2432 V1 EN (Equation 15)
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
100sec
Re UUBase
VT
VTprim
StartCurr
IBase×




















+ × ×
sec
100
CCT
CTprim
VDepFactsec
×






100
IECEQUATION2433 V1 EN (Equation 16)
Third part of the characteristic (UHighLimit/100*UBase ≤ Restrain voltage):
StartCurr
IBase
CT
CTprim100
× ×
sec
IECEQUATION2434 V1 EN (Equation 17)
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°
1MRK 511 360-UEN A Section 10
Testing functionality by secondary injection
Bay control REC670 2.1 IEC 115
Commissioning manual