Siemens SIPROTEC 7UM62 User Manual

Functions
2.16 Underexcitation (Loss-of-Field) Protection (ANSI 40)
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
140
Figure 2-57 Capability Curve of a Salient-Pole Generator, Indicated per Unit
Example:
U = U
N
= 6300 V
I = I
N
S
N
= 5270 kVA
f
N
= 50.0 Hz
n
N
= 1500 RPM
cos ϕ = 0,800
x
d
= 2,470
x
q
= 1,400
The primary setting values can be read out directly from the diagram. The related values must be converted for
the protection setting. The same conversion formula can be used if the protection setting is performed with the
predefined synchronous direct reactance.
with
x
dsec
related synchronous direct reactance, secondary,
x
d Mach
related synchronous direct reactance of the machine,
I
N Mach
Nominal current of the machine
U
N Mach
Nominal Voltage of the Machine
U
N, VTprim
Primary Nominal Voltage of the voltage transformers
I
N, CT prim
Nominal primary CT current

Siemens SIPROTEC 7UM62 Specifications

General

Brand	Siemens
Model	SIPROTEC 7UM62
Category	Protection Device
Language	English