ABB RELION 670 Series Applications Manual page 154

Section 8
Current protection
S TD S
=
EQUATION1893-ANSI V1 EN-US
Where
S
S
old
S
Calculated
TD
The value of
long.
The calibration factors for current and voltage measurement errors are set % of rated current/
voltage:
IMagComp5, IMagComp30, IMagComp100
VMagComp5, VMagComp30, VMagComp100
IAngComp5, IAngComp30, IAngComp100
The angle compensation is given as difference between current and voltage angle errors.
The values are given for operating points 5, 30 and 100% of rated current/voltage. The values
should be available from instrument transformer test protocols.
148
( )
TD S
1
⋅ + − ⋅
Old Calculated
is a new measured value to be used for the protection function
is the measured value given from the function in previous execution cycle
is the new calculated value in the present execution cycle
is settable parameter
TD = 0.92 is recommended in generator applications as the trip delay is normally quite
1MRK 511 364-UUS A
(Equation 79)
Application manual