ABB Relion 670 Series Technical Reference Manual page 431

1MRK505222-UUS C
ANSI09000684 V1 EN
Figure 213: Simplified logic diagram for negative sequence overcurrent stage x , where x=1, 2, 3 or 4
Technical reference manual
itself. The direction of the fault is determined in common "Directional Supervision
Element" described in the next paragraph.
• Negative sequence current pickup value.
• Type of operating characteristic (Inverse or Definite Time). By this parameter
setting it is possible to select Inverse or definite time delay for negative sequence
overcurrent function. Most of the standard IEC and ANSI inverse characteristics
are available. For the complete list of available inverse curves, refer to Chapter
"Inverse time characteristics"
• Type of reset characteristic (Instantaneous / IEC Reset /ANSI reset).By this
parameter setting it is possible to select the reset characteristic of the stage. For the
complete list of available reset curves, refer to Chapter
• Time delay related settings. By these parameter settings the properties like definite
time delay, minimum operating time for inverse curves, reset time delay and
parameters to define user programmable inverse curve are defined.
• Multiplier for scaling of the set negative sequence current pickup value by external
binary signal. By this parameter setting it is possible to increase negative sequence
current pickup value when function binary input MULTPUx has logical value 1.
Simplified logic diagram for one negative sequence overcurrent stage is shown in the
following figure:
Section 7
Current protection
"Inverse time characteristics"
425