ABB REG670 - Calibration of Analog Inputs

( )
Old Calculated
S k S 1 k S= × + - ×
EQUATION1959 V1 EN (Equation 87)
Where
S is a new measured value to be used for the protection function
S
old
is the measured value given from the function in previous execution cycle
S
Calculated
is the new calculated value in the present execution cycle
k
TD
is settable parameter by the end user which influence the filter properties
Default value for parameter k is 0.00. With this value the new calculated value is
immediately given out without any filtering (that is without any additional delay).
When k is set to value bigger than 0, the filtering is enabled. A typical value for k=0.92
in case of slow operating functions.
8.10.7.2 Calibration of analog inputs
Measured currents and voltages used in the Power function can be calibrated to get
class 0.5 measuring accuracy. This is achieved by amplitude and angle compensation
at 5, 30 and 100% of rated current and voltage. The compensation below 5% and
above 100% is constant and linear in between, see example in figure
196.
1MRK502052-UEN B Section 8
Current protection
425
Technical manual