IEEE PES Task Force on Benchmark Systems for Stability ...Benchmark System #1 & Benchmark System #2...
Transcript of IEEE PES Task Force on Benchmark Systems for Stability ...Benchmark System #1 & Benchmark System #2...
Benchmark System #1
&
Benchmark System #2
N. Martins
CEPEL
National Harbor, MD, July 27-31, 2014
2014 IEEE Power & Energy Society General Meeting
IEEE PES Task Force on Benchmark Systems for Stability Controls
2
Benchmark System #13-Machine Infinite Bus System
Outline
� Desirable features of the system
� System description
� Eigenanalysis
� PSS/E - ANATEM/PacDyn comparative results
� Conclusions
3
Desirable Features of 3MIB System� Effectiveness of PSS to simultaneously contribute to
the damping of three electromechanical modes.
�These are modes of different nature:
�Intraplant
�Interplant
�Inter-area
�A well-designed PSS should be able to:
� provide good to excellent intraplant and local
mode damping under practically all operating
conditions
�adequately contribute to the damping control of
inter-area modes.
5
3MIB System description (2/2)� Synchronous machine models consider transient
and subtransient effects in d and q axes.
� First order AVR models (IEEEST1A).
� Generators #1 and #2: Typical hydro-generator parameters.
� Generator #3: typical turbine-generator parameters.
� Load types:
Bus Active power Reactive Power
#480% constant-I
20% constant-Z100% constant-Z
#5 100% constant-P 100% constant-Z
6
Rotor speed mode-shapes
-1 0 1-1
0
1Mode M1 (1.43 Hz)
#1
#2
-1 0 1-1
0
1Mode M2 (1.25 Hz)
#1
#2 #3
-1 0 1-1
0
1Mode M3 (0.39 Hz)
#1#2#3
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2
0
2
4
6
8
10
12
14
1616
14
12
10
8
6
4
20.98
0.86
0.74
0.6
0.48 0.36 0.24 0.12 0.06
Mode M1
Mode M2
Mode M3
Real [1/s]
Imag
[ra
d/s]
7
Uncompensated 3MIB system
Four eigensolutions
produced by raising
the values of a pure
gain PSS at gen. #1.
-3 -2.5 -2 -1.5 -1 -0.5 0 0.50
2
4
6
8
10
1212
10
8
6
4
2
Real [1/s]
Imag
[ra
d/s]
8
Residues of Δω(s)/ΔVref(s) for Gen #1With (blue) and without (red) phase compensation.
-9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2
0
2
4
6
8
10
12
14
1616
14
12
10
8
6
4
20.98
0.86
0.74
0.6
0.48 0.36 0.24 0.12 0.06
Real [1/s]
Imag
[ra
d/s]
9
Phase-Compensated 3MIB system
Six eigensolutions
produced by
raising the gains
of phase-advance
PSSs at gen. #1
and #2.
10
ANATEM vs PSS/E Validation (1/2)
0 2 4 6 8 10 12 14 16 18 20
1398
1400
1402
1404
1406
1408
CaseA-noPSS
Time (s)
Pe (
MW
) G
en #
1
ANATEM
PSS/E
50 MVAr Reactor at Bus #5, No PSS
11
ANATEM vs PSS/E Validation (2/2)Steps in the AVRs references, No PSS
0 2 4 6 8 10 12 14 16 18 20
1350
1400
1450
CaseB-noPSS
Time (s)
Pe (
MW
) G
en #
1
ANATEM
PSS/E
12
PacDyn vs PSS/E LSYSAN Validation (1/2)
-30 -25 -20 -15 -10 -5 00
5
10
15
a)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
-2 -1.5 -1 -0.5 0 0.50
1
2
3
4
5
6
7
8
9
10b)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
All modes Electromechanical modes
13
PacDyn vs PSS/E LSYSAN Validation (2/2)
-1 -0.5 0 0.5 1-1
-0.5
0
0.5
1a) 1.43 Hz
-1 -0.5 0 0.5 1-1
-0.5
0
0.5
1b) 1.22 Hz
-1 -0.5 0 0.5 1-1
-0.5
0
0.5
1c) 0.39 Hz
Rotor speed mode-shapes
(×) PSS/E LSYSAN
(○) PacDyn
14
Conclusions on the 3MIB System�The 3MIB results show that good PSS designs
simultaneously contribute to the damping of
electromechanical modes of different nature.
�Three electromechanical modes are clearly
identified from the system eigensolution:
�Intraplant, interplant and inter-area.
�The PSS/E and ANATEM/PacDyn datafiles can be
downloaded from the Task Force website:
�Time-domain simulations and eigenanalysis
from both software show good matching .
15
Benchmark System #2The Brazilian 7-Bus Equivalent Model
Outline
� Desirable features of the system
� System description
� Eigenanalysis
� PSS/E - ANATEM/PacDyn comparative results
� Conclusions
16
Desirable Features of the System�Poor controllability via single generator excitation
control loop over a critical inter-area mode.
�Presence of a poorly-damped complex-conjugate
pair of zeros in the Itaipu AVR transfer function:
�These zeros, through system changes, approach
the pole pair to be damped, reducing the
generator damping control.
�Negligible controllability when near pole-zero
cancellation.
4ITAIPU
1.03948.5
1 62.6
24.3
6500.0
1957.9R
1 0.0
-39.7
6IVAIPORA
0.98921.4
-4.9
79.81
0.0
-2097.2
6437.3
1973.4
-6315.6
1109.0
1
5IVAIPORA
0.99821.2
845.8
-9.2
1 0.0
-32.9
1.0000
1.0000
109.3
-224.8
7EQUIVALENT
0.9660.0
1 2884.0
-196.0
1 -3164.3
952.3R
1 0.0
-39.2
6211.2
1133.1
-6048.3
1187.61
227.3
1
1FOZ AREIA
1.03024.5
2405.0
-467.0
1 1658.0
-412.3R
1 0.0
-190.1252.9
120.5
-251.5
-102.4
2S. SANTIAGO
1.03027.2
1 692.3
-184.0
1 1332.0
-200.3R
1 0.0
488.6
137.5
-484.9
-82.8
3S. SEGREDO
1.029
688.2
-235.01
1540.0
-446.7R
1 0.0
-120.9
151.1
4.4
-151.0
-2.8
-999.9
124.3
1002.8
-88.0
-158.2
1
1
-109.3
IEEE BENCHMARK SYSTEMBRAZILIAN 7-BUS EQUIVALENT SYSTEMTUE, OCT 01 2013 10:16
17
System description (1/2)
Red: 500 kV
Black: 765 kV
18
System description (2/2)
� Synchronous machine models:
� consider transient and subtransient effects in d and q axes.
� salient-pole rotor.
� All machines with identical AVR models (IEEEST1A).
� Δω-PSS in all machines except generator #7 (EQUIVALENT).
� Line chargings represented by shunt capacitors.
� Load model: 100%I for P and 100%Z for Q.
19
Interarea modes
� Mode 1 (unstable): oscillation of the Itaipu power plant against the Southern and Southeastern systems.
� Mode 2: oscillation of the Southern system (Salto Santiago (#2), Salto Segredo (#3) and Foz do Areia (#1) power plants) against the Southeastern system and the Itaipu power plant combined.
21
Pt/Vref Residues� Pt_i/Vref_i transfer function residues for the
unstable pole:
� First approach: stabilize the system with PSS only at Itaipu.
Generator Residue
Itaipu 6.70 ∟31.6°
Equivalent 5.55 ∟165°
F. Areia 0.044 ∟162°
S. Segredo 0.042 ∟160°
S. Santiago 0.027 ∟144°
22
Stabilization with one PSS (1/2)
� The zeros with positive real part in the stabilization loop of Itaipu attract the unstable poles as the PSS gain is increased.
(*) Poles (○) Zeros
23
Stabilization with one PSS (2/2)
� The unstable root locus branch tends to the RHP zero as the PSS gain is increased.
24
Stabilization with two PSS (1/2)
� The system can be stabilized by the addition of ∆ω-PSSs to Itaipu and Segredo generators.
(*) Poles (○) Zeros
26
Stabilization with three PSS
� The addition of PSSs to Segredo, Areia and Santiago generators is not sufficient to stabilize the system.
� There exists a complex pair of zeros closely located to the unstable pole pair.
� By combining local and remote signals to the input of the Itaipu generator, the system can be stabilized with two PSS.
27
ANATEM vs PSS/E Validation (1/2)50 MVAr Reactor at Bus #6, PSS only at Itaipu
0 2 4 6 8 10 12 14 16 18 20
1657
1657.5
1658
1658.5
1659
CaseA-PSSita - Gen #1
Time (s)
Pe (
MW
)
ANATEM
PSS/E
CaseA-allPSS - Gen #1
28
ANATEM vs PSS/E Validation (2/2)Step in the AVR reference of Itaipu, PSS only at Itaipu
0 2 4 6 8 10 12 14 16 18 20
1654
1656
1658
1660
1662
CaseB-PSSita - Gen #1
Time (s)
Pe (
MW
)
ANATEM
PSS/E
CaseB-allPSS - Gen #1
29
PacDyn vs PSS/E PSSLT Validation (1/2)
All modes Electromechanical modes
-25 -20 -15 -10 -5 00
1
2
3
4
5
6
7
8
9
a)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
-2 -1.5 -1 -0.5 0 0.50
1
2
3
4
5
6
7
8
9
10b)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
System without PSS
30
PacDyn vs PSS/E PSSLT Validation (1/2)
All modes Electromechanical modes
System with PSS at all generators
-70 -60 -50 -40 -30 -20 -10 00
10
20
30
40
50
a)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
-5 -4 -3 -2 -1 00
5
10
15b)
Real (1/s)
Imag
(ra
d/s)
ANATEM
PSS/E
31
Conclusions�Pole-zero analysis shows the inherent modal
controllability problem (TF zeros in the vicinity of
the electromechanical mode to be damped).
�Test system needs 2 PSSs to be stabilized.
�The PSS/E and ANATEM/PacDyn datafiles can be
downloaded from the Task Force website:
�Verified differences in the time-domain
simulations are under investigation.
�Higher mismatch in the eigenvalue calculation
for the well damped system.