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1.2 INTRODUCTION
1
In the ALPS relay the four straight lines of the quadrilateral characteristic are developed by a combination of the following
three characteristics:
1.
Reactance characteristic (section 1). The tilt of the reactance characteristic is determined by the characteristic timer
setting. The range of the setting is 80° to 155° in 1° steps.
2.
Restricted directional characteristic (sections 2 and 4)
3.
Right (positive) resistive blinder (section 3)
The following definitions pertain to all of the distance functions:
I
= phase A current at relay
A
I
= phase B current at relay
B
I
= phase C current at relay
C
I
= zero-sequence current at relay
0
V
= phase A to ground voltage at relay
A
V
= phase B to ground voltage at relay
B
V
= phase C to ground voltage at relay
C
X
= positive-sequence component of X
1
X
= negative-sequence component of X
2
X
= memory (pre-fault) value of X
M
= Zone x positive-sequence reach setting: ZxR ∠ POSSEQANG
Z x
1
= Zone x zero-sequence reach setting: ZxR ∠ ZERSEQANG
Z x
0
Note: The magnitudes of Zx
K
1 = Zone 1 zero-sequence compensation factor: Z1K0
0
K
= zero-sequence compensation factor
0
a) REACTANCE CHARACTERSTIC
The reactance characteristic used for the ground quadrilateral is the similar as the existing negative / zero sequence phase
angle comparator reactance characteristic. The function has been modified by the addition of a fourth comparator input
(Pol. #3). The operate and polarizing signals used in this function are:
Iφ ' Z – Vφ
Operate:
Pol.# 1:
I
Z
0
1
Pol.# 2:
I
Z
2
1
Pol.# 3:
I
Z
1 F
Iφ ' Z is the compensated IZ product
where:
Z
is the positive sequence replica impedance
1
Vφ is the phase to ground voltage
I
is the zero sequence current component
0
I
is the negative sequence current component, referenced to the proper phase.
2
I
is the fault component of the positive sequence current component, referenced to the proper phase.
1 F
The pre-fault load current is removed from this quantity.
1-6
X
4
Figure 1–1: GROUND DISTANCE QUADRILATERAL CHARACTERISTIC
and Zx
are identical - these quantities differ in phase angle only.
1
0
1
ALPS Advanced Line Protection System
1
3
2
1 PRODUCT DESCRIPTION
R
GE Power Management
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