ALPS™ ALPS™ Advanced Line Protection System Advanced Line Protection System
ALPS™ALPS™Advanced Line Protection SystemAdvanced Line Protection System
2
Modified Fourier Calculation
ALPS Advanced Line Protection System
• High Speed Sampling
• Phaselet Calculation
• Variable Window
• Digital Mimic
High Speed Sampling
ALPS Advanced Line Protection System
-20
-15
-10
-5
0
5
10
0 4 8 12 16 20 24 28 32 36 40PHSLT
# 4
16
SAMPLES
PHSLT
# 8
32
SAMPLES
EXECUTEPHASELET
CALCULATIONAND PROTECTIONALGORITHMS
PHSLT
# 1PHSLT
# 2
PHSLT
# 3
PHSLT
# 5
PHSLT
# 6
PHSLT
# 7
PHSLT
# 9
PHSLT
# 10
4
Discrete Fourier Transform
ALPS Advanced Line Protection System
v t V t
VrealN
Vkk
N
VimagN
Vkk
N
peak
k
N
k
N
( ) cos( )
( ) [ cos( )]
( ) [ sin( )]
= • +
= • • • •∑
= • − • • •∑
=
−
=
−
ω φ
π
π
22
22
0
1
0
1
5
Full Cycle Fourier Transform
ALPS Advanced Line Protection System
-20
-15
-10
-5
0
5
10
15
20
0 64 128 192 256 320
WINDOW 1WINDOW 2
WINDOW 3
6
Phaselet Definition
ALPS Advanced Line Protection System
• Phaselets are partial sums of the products of
the waveform samples and the sine/cosine
coefficients.
• Input signals are sampled 64 times per cycle;
protection algorithms are executed 16 times
per cycle.
• Groups of phaselets may be added together
and transformed to create a phasor.
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Phaselet Calculation
ALPS Advanced Line Protection System
Phaselet al C X
Phaselet aginary S X
Where
p kk p P P
p P
k
pk p P P
p P
k k
Re
Im
:
= ∑ ⋅
= −∑ ⋅
=
= ⋅ − +
⋅
= ⋅ − +
⋅1
1
C , S Sine and Cosine Coefficients
p = phaselet index: there are N / P phaselets per cycle
P = the number of phaselets per cycle
X = kth sample of the input signal
k k
k
8
-20
-15
-10
-5
0
5
10
0 4 8 12 16 20 24 28 32 36 40PHSLT
# 4
16
SAMPLES
PHSLT
# 8
32
SAMPLES
EXECUTEPHASELET
CALCULATIONAND PROTECTIONALGORITHMS
PHSLT
# 1PHSLT
# 2
PHSLT
# 3
PHSLT
# 5
PHSLT
# 6
PHSLT
# 7
PHSLT
# 9
PHSLT
# 10
Variable Window
ALPS Advanced Line Protection System
9
Phasor Calculation
ALPS Advanced Line Protection System
Phasor al
Phasor aginary
T nW T n W
T n W T n W
PhasorSum al
PhasorSum aginary
n
n
RR RI
IR II
n
n
Re
Im
( , ) ( , )
( , ) ( , )
Re
Im
=
•
Phaselets are converted to phasors by the following:
Where:
PhaseletSum al Phaselet aln p
p nW
P
n
Re Re=
= − +
∑1
PhaseletSum aginary Phaselet aginaryn p
p nW
P
n
Im Im= ∑= − +1
n = Phasor index (N/P) W = Window size in samples
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Phasor Calculation
ALPS Advanced Line Protection System
For a one cycle window, the Fourier calculation becomes:
P h a so r a lN
P h a s e l e t a l
P h a so r a g in a ryN
P h a s e l e t a g in a ry
n p
p nN
P
n
n p
p nN
P
n
R e R e
Im Im
= ⋅ ∑
= ⋅ ∑
= − +
= − +
2
2
1
1
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Variable Window Fourier Transform
ALPS Advanced Line Protection System
PRE-FAULT
ONE CYCLE
WINDOW
VARIABLE WINDOW
-20
-15
-10
-5
0
5
10
15
0 64 128 192 256 320
12
Mimic Algorithm
ALPS Advanced Line Protection System
Time Domain:
Sampled Data:
IZ t I t Rd
dtI t L( ) ( ) ( ( ))= • + •
IZkI k I k
RI k I k
L( )( ( ) ( )) ( ( ) ( ))+ = + + • + + − •δ δ δ
δ2 2
13
EXAMPLES OF
ADAPTIVE PROTECTION
ALGORITHMS
ALPS Advanced Line Protection System
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Adaptive Polarizing Memory
Remote line end three phase faults:
Reverse zero voltage faults:
ZLZS3 PH
3 PH
ZS = 19 ZL
Vr = 0.05 Rated
Vr = 0
ALPS Advanced Line Protection System
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Adaptive Polarizing Memory
Extend memory time if:
• Voltage at the relay is less than 10% of rated.
AND
• Any distance measuring function is picked up.
ALPS Advanced Line Protection System
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Adaptive Polarizing Memory
ALPS Advanced Line Protection System
Reset memory if:
• Voltage at the relay is greater than 10% of rated.
AND
• Distance measuring function resets.
17
Variable Reach Zone 1
Z LINE
FINAL REACH
INITIAL REACH
ALPS Advanced Line Protection System
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Variable Reach Zone 1
Zone 1 reach is set to 90 % of ZL.
WINDOW SIZE % OF SET REACH
1/16 Cycle 0 (can not operate)
1/8 Cycle 33%
3/16 Cycle 65%
1/4 Cycle 75%
5/16 Cycle 83%
1/2 Cycle 90%
> 1/2 Cycle 100%
ALPS Advanced Line Protection System
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Adaptive Reactive Unit Supervision
Reactance type distance functions require
supervision to prevent operation on normal load
flow.
The traditional approach is to use a fixed
resistive blinder, or a fixed reach mho function.
ALPS Advanced Line Protection System
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Adaptive Reactive Unit Supervision
X -
ZL min
X' - ZL max
Fixed
mho
Fixed
Blinder
Adaptive
mho
Reactance
Unit
Adaptive
Blinder
ALPS Advanced Line Protection System
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EVALUATION OF
DISTANCE RELAY
OPERATING SPEED
ALPS Advanced Line Protection System
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Modeled System
Protected Line
Parallel Line
Z1 = 6.0 ohms @ 86 degZ0 = 18.3 ohms @ 76 deg
Z1S = 1.5 ohms @ 86 degZ0S = 1.5 ohms @ 86 deg
Z1S = 1.5 ohms @ 86 degZ0S = 1.5 ohms @ 86 deg
ALPS Advanced Line Protection System
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PC Simulation Trip Times
0
5
10
15
20
0 25 50 75
% of Line
Tim
e (mS)
ALPS Advanced Line Protection System
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MPS Test Results
0
5
10
15
20
0 25 50 75
% of Line
Tim
e (mS)
ALPS Advanced Line Protection System
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The ALPS Advanced Line Protection
System gives you the protection
choices you need. Whether you’re
protecting compensated or
uncompensated lines; require single
phase tripping or three phase tripping,
with or without reclosing, its available.
ALPS Advanced Line Protection System
ALPS Advanced Line Protection System
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APPLICATION
• Distance protection for EHV lines
• Series compensated lines
• High speed tripping (half cycle)
• Single and three phase tripping
Providing complete transmission line protection,
ALPS is a multi-function digital protective relay
system intended to provide distance protection for
HV or EHV transmission lines.
ALPS Advanced Line Protection System
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Single Line Diagram
ALPS Advanced Line Protection System
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PROTECTION
• Four zones of distance protection
• Pilot protection, step distance backup
• Out of step blocking and tripping
• Phase instantaneous overcurrent
• Ground instantaneous overcurrent
• Ground time overcurrent backup
• Over and under voltage functions
ALPS Advanced Line Protection System
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CONTROL
• Optional four shot recloser
• Configurable inputs and outputs
• Fully configurable relay logic
ALPS Advanced Line Protection System
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INPUTS/OUTPUTS
All contact converter inputs and all contact outputs
(except for alarms) in ALPS are configurable by the
user.
• 8 configurable inputs, or 12 for single
phase tripping
• 15 configurable outputs, or 20 for single
phase tripping
ALPS Advanced Line Protection System
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RMS METERING
• Current (Ia, Ib, Ic, In)
• Voltage (Va, Vb, Vc)
• Watts (3 phase)
• Vars (3 phase)
• Frequency
ALPS Advanced Line Protection System
32
MONITORING
• fault location provided by a single ended
• fault location algorithm
• trip circuit monitor
• self test diagnostics
• event reporting of last 100 events
• fault reports
• high resolution oscillography
ALPS Advanced Line Protection System
33
USER INTERFACE
• 20 button keypad and 4 line LCD display
• RS232 serial port on front of unit
• RS232 and RS485 ports on rear of unit
• communication software
• IRIG-B input for time synchronization
ALPS Advanced Line Protection System