Setting Guidelines For Reference Vector Group; Figure 59: P643 Using Spare Ct Input For Overcurrent Protection - GE P642 Technical Manual

Chapter 6 - Transformer Differential Protection
V03122

Figure 59: P643 Using spare CT input for overcurrent protection

5.8

SETTING GUIDELINES FOR REFERENCE VECTOR GROUP

The following table shows how to set the zero sequence filter for the different Ref Vector Group options.
Ref Vector Group
0
1
2
3
4
5
6
7
8
9
10
11
In the majority of applications, the reference vector group setting Ref Vector Group is set to 0. However there are
occasional applications where it may be desirable to set it to a value other than 0.
One example is to increase the sensitivity for phase-to-phase faults where it is used to protect a YNyn0
transformer. In this scenario, the P64x would normally apply a -30° phase shift to both HV and LV windings due to
the way it works. However, by setting the reference vector group to 1, the device knows it does not have to apply a
-30° shift in its calculations, thus increasing its sensitivity to phase-to-phase faults.
136
Zero seq filt HV setting
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Zero seq filt LV setting
Disabled
Disabled
Enabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
Disabled
P64x
Zero seq filt TV setting
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
Disabled
Enabled
P64x-TM-EN-1.3