BE1-951
Protection and Control
4-21
Table 4-13. S<g>-67N Command Settings
Setting
Range/Purpose
Default
Mode
QVI = Use all three polarization methods for neutral elements
QV = Use negative and zero sequence polarization for neutral elements
QI = Use negative sequence and current polarization for neutral
elements
VI = Use zero sequence and current polarization for neutral elements
Q
= Use negative sequence polarization for neutral elements
V
= Use zero sequence polarization for neutral elements
I
= Use current polarization for neutral elements
QVI
Zero
Sequence
Voltage
Polarization
Quantities
VOIN=Reference Quantity is the calculated zero sequence voltage (V0)
Operate Quantity is the calculated zero sequence current (IN)
VOIG=Reference Quantity is the calculated zero sequence voltage (V0)
Operate Quantity is the measured ground current on the ground
CT input (IG)
VXIN=Reference Quantity is the measured ground voltage on the Aux
voltage input (VX)
Operate Quantity is the calculated zero sequence current (IN)
VXIG=Reference Quantity is the measured ground voltage on the Aux
voltage input (VX)
Operate Quantity is the measured ground current on the ground
CT input (IG)
VOIN
S<g>-67N command
Purpose:
Read/Set 67 Neutral Polarizing Mode and Quantities
Syntax : S<g>-67N[=<Mode>,
<Quantity>]
Comments:
g = setting group 0, 1, 2, or 3. See Table 4-15 for S<g>75N settings information.
Example: Set the neutral polarizing mode to use all three polarizing methods.
1.
>S0-67N=QVI, VOIN
Modes QVI, QV, QI, VI are logical OR’s of modes Q, V, and I, and are used to setup dual or possibly triple
polarization techniques for the neutral elements. Thus if more than one directional supervision element is
enabled, any one can enable tripping if the appropriate forward or reverse directional decision is made.
The directional algorithm requires the power line impedance parameters. These parameters are inputted
into the BE1-951 using the SG-LINE command.
Table 4-14. SG-LINE Command Settings
Setting
Range
Increment
Unit of
Measure
Default
Positive Sequence Magnitude (Z1)
0.05 to 200
0.05
Ohms
8
Positive Sequence Impedance Angle (A1)
0 to 90
1
Degrees
80
Zero Sequence Magnitude (Z0)
0.05 to 650
0.05
Ohms
24
Zero Sequence Impedance Angle (A0)
0 to 90
1
Degrees
80
Length of Power Line (LL)
0.01 to 650
0.01
Units
100
SG-LINE Command (HMI Screen 6.3.12)
Purpose:
Read/Set System Line parameters
Syntax :
SG-LINE[=<Z1>,<A1>,<Z0>,<A0>,<LL>]
Comments:
See Table 4-13 for SG-LINE settings information.