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889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
PROTECTION
CHAPTER 4: SETPOINTS
Figure 4-52: Third Harmonic Voltage Difference Application Example
We have the magnitude of neutral voltage V
N
as:
and the magnitude of the neutral and zero-sequence voltages |V
N
+ V
0
| as:
Therefore, under the normal conditions described above, we set the operating quantities
as follows:
In actual practice, the |V
N
| / |V
N
+ V
0
| ratio may vary from 0.4 to 0.85 under normal
conditions. The pickup and supervision setpoints are determined by evaluating the
operating quantities during a fault condition (refer to example 2 for details).
Vn
(3rd)
Va
Vb
Vc
Va Vb Vc
E3
E3
E3
Vn
k
3V
0
(3rd)
Pickup
3rd)
(
)
rd
3
(
)
rd
3
(
0
V
V
V
n
n
and
Pickup
1
3rd)
(
)
rd
3
(
)
rd
3
(
0
0
V
V
V
n
and
n
Supervisio
3rd)
(
)
rd
3
(
0
V
V
n
3
rd
3V
0
894141.cdr
Содержание Multilin 889
Страница 10: ...VIII 889 GENERATOR PROTECTION SYSTEM INSTRUCTION MANUAL ...
Страница 126: ...3 48 889 GENERATOR PROTECTION SYSTEM INSTRUCTION MANUAL SOFTWARE INTERFACE CHAPTER 3 INTERFACES ...
Страница 530: ...4 400 889 GENERATOR PROTECTION SYSTEM INSTRUCTION MANUAL TESTING CHAPTER 4 SETPOINTS ...
Страница 575: ...CHAPTER 8 MAINTENANCE ENVIRONMENTAL HEALTH REPORT 889 GENERATOR PROTECTION SYSTEM INSTRUCTION MANUAL 8 3 ...
Страница 580: ...A 4 889 GENERATOR PROTECTION SYSTEM INSTRUCTION MANUAL REVISION HISTORY CHAPTER A APPENDIX A ...