Technical Data; Loss Of Excitation Lexpdis; Identification; Functionality - ABB REG650 Technical Manual

1MRK 502 034-UEN -
6.1.7
6.2
6.2.1
6.2.2
Technical Manual

Technical data

Table 38: ZGPDIS technical data
Function
Number of zones
Forward positive sequence impedance
Reverse positive sequence impedance
Angle for positive sequence impedance,
Timers
Operate time
Reset ratio

Loss of excitation LEXPDIS

Identification

Function description
Loss of excitation

Functionality

There are limits for the low excitation of a synchronous machine. A reduction of
the excitation current weakens the coupling between the rotor and the stator. The
machine may lose the synchronism and start to operate like an induction machine.
Then, the reactive power consumption will increase. Even if the machine does not
loose synchronism it may not be acceptable to operate in this state for a long time.
Reduction of excitation increases the generation of heat in the end region of the
synchronous machine. The local heating may damage the insulation of the stator
winding and the iron core.
To prevent damages to the generator it should be tripped when excitation becomes
too low.
Impedance protection
Range or value
3
(0.005-3000.000) Ω/
phase
(0.005-3000.000) Ω/
phase
(10-90) degrees
(0.000-60.000) s
55 ms typically
105% typically
IEC 61850 IEC 60617
identification identification
LEXPDIS
SYMBOL-KK V1 EN
Section 6
Accuracy
-
± 2.0% static accuracy
Conditions:
• Voltage range:
(0.1-1.1) x U
r
• Current range:
(0.5-30) x I
r
• Angle: at 0 degrees
and 85 degrees
-
-
± 0.5% ± 10 ms
-
-
ANSI/IEEE C37.2
device number
40
Z<
123