GE LPS-D, Инструкция по эксплуатации

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GE Power Management LPS-D Line Protection System 6-
11
6 FUNCTIONAL TESTS (USER SETTINGS) 6.5 ZONE REACH TESTS
6
6.5 ZONE REACH TESTS 6.5.1 GENERAL CONSIDERATIONS
Testing the reach of the relay requires a few organized steps, as follows:
1. Choosing a test current (IT) for the impedance of the reach.
2. Calculating the voltage range in which the unit will pick up.
3. Applying the test voltage and currents in accordance with the test procedure.
Equations are given for calculating the pickup voltage for a chosen current magnitude and phase. If you wish to
test the complete characteristic, the software program, ALPS-Test, can be used to generate test currents and
voltage pickups for the complete characteristic. ALPS-Test is included the LPS-D software suite on the GE
Power Systems Products CD.
6.5.2 ZONE 1–4 PHASE-TO-GROUND CALCULATIONS
This section describes how to determine the test currents and voltages for Z1G, Z2G, Z3G and Z4G. The same
procedure is used for each zone to determine the test values. The procedure is as follows:
1. Choose a test current.
2. Calculate the impedance of the zone.
3. Calculate the operate voltage at the test current and impedance.
The test current, I
T
, is determined from Table 6–1: TEST CURRENT RANGES FOR PHASE-TO-GROUND
REACH on page 6–12. The value of I
T
is chosen according to the reach of the zone. The nominal pickup volt-
age, V
NOM
, is calculated with respect to I
T
and to several settings of the relay.
The pickup voltage calculations at a particular magnitude and phase of I
T
are referenced to the
faulted phase under test. For instance, if a BG Fault was applied, the current angles would be with
respect to the phase angle of VB.
The nominal pickup voltage is given by
(eq. 6–19)
for , or
(eq. 6–20)
for .
a) DEFINITIONS
Z = Calculated Impedance
Z
R
= Relay reach for Z1GROUND, Z2GROUND, Z3GROUND, or Z4GRND
øZ = Angle of maximum reach
I
T
= Test current for I
op
, chosen for the zone
øT = Characteristic timer of the zone
øI = Test current angle with respect to the faulted phase
K
0
= Zero-sequence compensation factor of the zone
POSSEQANG = Positive-sequence angle of maximum reach
ZERSEQANG = Zero-sequence angle of maximum reach.
NOTE
V
N OM
Z Z
R
I
T
⋅ ⋅
∅
I
∅
Z –
∅
T – 90
°
+
( )
cos
-------------------------------------------------------------------
 
 
∅
I
∅
Z
–
∅
T
–
90
°
–
( )
cos
⋅
=
∅
Z
∅
T 180
°
– +
( ) ∅
I
∅
Z
< <
V
NOM
Z Z
R
I
T
⋅ ⋅
∅
I
∅
Z
–
∅
T
– 90
°
+
( )
cos
-------------------------------------------------------------------
 
 
∅
I
∅
Z
–
∅
T
90
°
– +
( )
cos
⋅
=
∅
Z
∅
I
∅
Z
∅
T
–
180
°
+
( ) < <