ABB Relion 650 Series Technical Manual page 435

1MRK 506 326-UUS B
Default value for parameter
out without any filtering (that is, without any additional delay). When
0, the filtering is enabled. Appropriate value of
application. Some typical value for
Zero point clamping
In order to avoid erroneous measurements when either current or voltage signal is not present,
the magnitude level for current and voltage measurement is forced to zero. When either current or
voltage measurement is forced to zero automatically the measured values for power (P, Q & S) and
power factor are forced to zero as well. Since the measurement supervision functionality, included
in the CVMMXN function, is using these values the zero clamping will influence the subsequent
supervision (observe the possibility to do zero point clamping within measurement supervision,
see section
Compensation facility
In order to compensate for small magnitude and angular errors in the complete measurement
chain (CT error, VT error, IED input transformer errors and so on.) it is possible to perform on site
calibration of the power measurement. This is achieved by setting the complex constant which is
then internally used within the function to multiply the calculated complex apparent power S. This
constant is set as magnitude (setting parameter
(setting parameter
parameters are done in such way that they do not influence internally calculated value (complex
constant has default value 1). In this way calibration, for specific operating range (for example,
around rated power) can be done at site. However, to perform this calibration it is necessary to
have an external power meter with high accuracy class available.
Directionality
CTStartPoint defines if the CTs grounding point is located towards or from the protected object
under observation. If everything is properly set power is always measured towards protection
object.
ANSI05000373 V2 EN-US
Figure 234: Internal IED directionality convention for P & Q measurements
Practically, it means that active and reactive power will have positive values when they flow from
the busbar towards the protected object and they will have negative values when they flow from
the protected object towards the busbar.
Line distance protection REL650
Technical manual
k is 0.00. With this value the new calculated value is immediately given
"Measurement supervision").
PowAngComp , default value 0.0 degrees). Default values for these two
Busbar
52
P Q
Protected
Object
ANSI05000373_2_en.vsd
© Copyright 2011 ABB Power Grids. All rights reserved
k shall be determined separately for every
k =0.14.
PowMagFact , default value 1.000) and angle
IED
Section 13
Monitoring
k is set to value bigger than
SEMOD54417-250 v4
SEMOD54417-253 v4
SEMOD54417-256 v5
429