CYG PRS-7367 User Manual

Protection Functions
PRS-7367 213
the characteristic circle of grounding MHM relay is offset to the first quadrant, and the value range
is 0°, 15° and 30°, it can be set by setting LNP_PE_Phi_Shift. Take a larger value for a short line
and a smaller value for a long line. It is recommended that 0° be set when the length of the line is
greater than or equal to 40KM, 15° be set when the length is greater than or equal to 10KM, and
30° be set when the length is less than 10KM.
3.45.2.2 Phase Current and Zero Sequence Current
When phase overcurrent protection operates, the corresponding phase which is overcurrent will
be judged as a faulty phase. When earth fault protection operates, the fault phase will be judged
by FPH element.
3.45.2.3 Directional element
For high voltage, earthed system is common, for middle and low voltage, the unearthed system is
common, so the Direction element use cross-polarizing (90°) connection type to meet different
conditions.
The cross-polarizing quantity is used to determine the fault direction(IaUbc/IbUca/IcUab).
The evaluation of the forward directionality is according to the equation:
-90
90 ( 5 ) arg 90 ( 5 )
I
j RCA
r
e
U
r
    
（ ）
Or
90 -
90 ( 5 ) arg 90 ( 5 )
U
j RCA
r
e
I
r
    
（ ）
The evaluation of the backward directionality is according to the equation:
-90
90 ( 5 ) arg 270 ( 5 )
I
j RCA
r
e
U
r
   
（ ）
Or
90 -
90 ( 5 ) arg 270 ( 5 )
U
j RCA
r
e
I
r
   
（ ）
5
o

is the max angle margin.
r
I
and
r
U
are the polarizing current and voltage. RCA is the
relay characteristic angle.
forward directionality and backward directionality can be set by setting LNP_PDIR_MOD.
RCA is the setting LNP_PRCA.
3.45.3 Settings
No
Name
Values(Range)
Unit
Step
Default
Description

CYG PRS-7367 Specifications

General

Brand	CYG
Model	PRS-7367
Category	Control Unit
Language	English