ABB RELION 615 Series Applications Manual page 88

Section 3
REG615 standard configurations
82
SEQSPVC1_FUSEF_U
X130_BI4_FIELD_EXCITATION_OPEN
GUID-9ED0D1CE-BE9A-49A4-8D10-7C6F9256D607 V2 EN
Figure 93: Underexcitation protection function
Three-phase underimpedance protection UZPDIS can be used as a backup protection
against phase faults by calculating impedance at the generator terminals.
SEQSPVC1_FUSEF_U
GUID-68EE57DC-DE37-41D8-873C-0CFBDDE32140 V2 EN
Figure 94: Underimpedance protection function
Overexcitation protection OEPVPH is provided to protect the generator against
overexcitation. Due to overexciation, saturation of the magnetic core of generator and
connected transformer may occur, and stray flux may be induced in nonlaminated
components that are not designed to carry flux. Excessive flux also causes excessive
eddy currents resulting into excessive voltage between laminations causing
overheating and damage to insulation.
SEQSPVC1_FUSEF_U
GUID-13AA0BEC-E4BB-4E84-B27D-963521760A42 V2 EN
Figure 95: Overexcitation protection function
General start and operate signals from all functions are connected to minimum pulse
timer TPGAPC1 for setting the minimum pulse length for the outputs. The output
from TPGAPC1 is connected to binary output.
UEXPDIS1
BLOCK OPERATE
EXT_LOS_DET START
UZPDIS1
BLOCK OPERATE
START
OEPVPH1
BLOCK OPERATE
START
BLK_RESTART
COOL_ACTIVE
1MRS758272 B
UEXPDIS1_OPERATE
UEXPDIS1_START
UZPDIS1_OPERATE
UZPDIS1_START
OEPVPH1_OPERATE
OEPVPH1_START
REG615
Application Manual