The Brazilian Wide Area Measurement System – Experience and Applications
description
Transcript of The Brazilian Wide Area Measurement System – Experience and Applications
EEL / UFSC
The Brazilian Wide Area Measurement System – Experience and Applications
Daniel Dotta
email: [email protected]
EEL / UFSC
Objective Wide Area Measurement System Overview Phasor Measurement Process
– Research going on at RPI The MedFasee Project
– LVPMS and HVPMS prototypes Blackout in the Brazilian Interconnected Power
System Selected Applications Conclusions
Presentation Structure
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To present an overview of the Brazilian experience with Wide Area Measurement Systems
Objective
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Wide Area Measurement System - WAMS
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Wide Area Measurement SystemOverview
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Simultaneous signals measurements at remote geographic locations using PMUs (Phasor Measurement Units).
GPS time synchronized measurements Data acquisition and handling in remote sites (PDC). Upgrade rate (scanning) >> SCADA. Allows dynamic monitoring and
control of electric systems. New paradigm for the system
operation.
EEL / UFSCPhasor Definition Complex number that represents a sine wave whose amplitude
(X) and angular frequency (ω) are time-invariant
The phasor module is equal to the rms signal value and the phase angle is the signal phase to t=0.
max 0
max
( ) cos( )
where 2
x t X tXX
X
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EEL / UFSCSynchrophasors Phasor measurements that occur at same time are
called “synchrophasors”.
Task not trivial: Involves large distances and high time precision. 7
Necessity of only one time reference – Synchronization!
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Update rate: 30-60 phasors per second
Time synchronized data High-speed communication
links Allows the dynamic system
monitoring
Update rate: each 2-5 seconds
No time synchronization Regular communication links
Allows stead-steaty system monitoring
SCADA(Supervisory Control and Data
Acquisition)
WAMS(Wide-Area Measurement System)
SCADA X WAMS(Comparasion)
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By SCADA By WAMS
How can the power system be seen?
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Phasor Measurement Process
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Basic Phasor Measurement Process Idea
Sine WaveWindow Size (points)
sf NfSampling rate
For N=12
0.014 0.016 0.018 0.02 0.022 0.024 0.026 0.028 0.03 0.032-1.5
-1
-0.5
0
0.5
1
1.5
Time(s)
Mag
nitu
de (p
u)
Time-Domain Signal
1/fs
N=12
12N
Sampling period1
ss
Tf
Regular sampling period (Ts)
12 60 720sf Hz 0.0014sT s
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Basic Phasor Measurement Process Idea
Time Domain Frequency Domain
( )n nx x tSamples
, 0, , -1n st nT n N
( )mjmX X e
2 , 0, , -1m m m NN where
DFT
0.014 0.016 0.018 0.02 0.022 0.024 0.026 0.028 0.03 0.032-1.5
-1
-0.5
0
0.5
1
1.5
Time(s)
Mag
nitu
de (p
u)
Time-Domain Signal
1/fs
N=12
12N
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Definition of DFT
Discrete Fourier Transform is a simple widely used method for phasor estimation
– Other methods have been discussed » Kalman filters, weighted least squares and neural networks
– Currently used in the commercial PMUs
Phasor Estimation
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0
2 N j nmN
m nn
X x eN
21
0
2 N j nN
nn
X x eN
Fundamental frequency component, set m=1
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Basic Phasor Measurement Architectures
Frequency Tracking Frequency Compensation
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Composed basically by– Analogic and digital filters– Phasor Estimation Methodology – Frequency Estimation Methodology
The most explored and applied is the frequency compensation architecture– Basically because use uniform sampling period
Basic Phasor Estimation Architecture
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Frequency Estimation is a key role in the both architectures– Changing the sampling window– Providing the frequency for phasor correction
Several methods are found in the literature– Zero Crossing– Least Error Squares– Kalman Filters– Demodulation– Phasor measurement angle changing
Frequency Estimation (Methodologies)
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Under off-nominal operation the phasor measured (Xmes) is different from the true value (Xtrue)– The effect of the off-nominal frequency can be expressed
by a P factor.
Pos-Processing(Off-nominal Frequency)
where
N - window sizew – actual frequencyw0 – nominal frequency
truemesX PX
00 ( )
( 1)2
0
( )sin2{ }( )sin2
tj N
N t
P etN
Phasor correction
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The P factor is directly influence by N and frequency value P behavior under frequency variation (N=48)
Pos-Processing(Off-nominal Frequency)
-5 -4 -3 -2 -1 0 1 2 3 4 50.985
0.99
0.995
1
1.005
-5 -4 -3 -2 -1 0 1 2 3 4 5-20
-10
0
10
20
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Frequency step (off-nominal operation)
Phasor Estimation (Discrete Fourier Transform)
0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4-20
-10
0
10
20Phase A - Signal Input
Mag
nitu
de (p
u)
0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.458.8
59
59.2
59.4
59.6
59.8
60
60.2
Time(s)
Freq
uenc
y (H
z)
Signal Frequency
EstimatedReal
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Sequence positive phasor estimation
Phasor Estimation (Discrete Fourier Transform)
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 211.308
11.31
11.312
11.314
11.316
Mag
nitu
de (p
u)
Magnitude Positive Sequence
Without Calibration FactorWith Calibration Factor
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2-200
-100
0
100
200
Time(s)
Deg
ress
Angle Positive Sequence
Before CorrectionAfter Correction
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MedFasee Project
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Brazilian Interconnected Power System - BIPS
Main Characteristics– Capacity of about 100 GW– Predominant hydroelectric
generation (about 71 %)– 90000 km of transmission
lines, with voltages ranging from 230 kV to 765 kV
– The largest powerplant, Itaipu, has 20 generators with a generation capacity of 14 GW, half in 60 Hz and half in 50 Hz
– Composed by 5 subsystems
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Project started in 2003 – The main goal was to develop the synchronized phasor
measurement technology in Brazil and study its applications
It resulted in two prototypes currently installed in Brazil:– LVPMS (Low Voltage Phasor Measurement System).
– HVPMS (High Voltage Phasor Measurement System).
The MedFasee R&D Project
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Medfasee Project(First Prototype)
Three PMUs were installed in laboratories of three universities in Southern Brazil
The PMUs measure the instantaneous three-phase distribution voltage
The PMUs have a network interface connected to the Internet to send the phasors to the PDC– 60 phasors/s
The PDC is located in the Electrical System Planning Research Laboratory (LabPlan) at UFSC
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PMU UTFPR
PMU PUC – RSPMU e PDC LabPlan – UFSC
MedFasee Project – Low VoltagePrototype Installation Details
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a) Frequency Evolution: b) Frequency Spectrum
System frequency oscillation mode ~ 0,02 Hz (period 50s).
Frequency Monitoring (12/01/2005) 15h00min00s e 15h29min59s)
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Firsts Disturbances Disturbance Southeast / Mid-West (14/03/2005 – 05h05min12s)
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MedFasee Low Voltage Phase II - National WAMS
Characteristics Develop, dissemination and educational use of
the WAMS technology Nine universities participate in the project Five geographical regions are covered Internet is used as commutation link
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Source: www.medfasee.ufsc.br/temporeal
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PMU UFSC – Florianópolis, SC– Installation Date: 30/11/2008
MedFasee LV - Installations
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PMU UFPA, Belém, PA– Installation Date: 06/11/2008
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MedFasee LV - Installations
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COPPE/UFRJ, Rio de Janeiro, RJ– Installation Date: 18/12/2008
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Phase II -> Conclusion
MedFasee LV - Installations
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Hardware:– DELL OptiPlex 755 – Core 2 Duo 3GHz, 2GB RAM,
2000 GB HD Software:
– Operation System - GNU/Linux + (RTAI)
– Oriented Object Modeling (C/C++)
– MySQL Database– Long-term historical database
Communication System:– Internet (VPN)
MedFasee LVPDC Installation - UFSC
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MedFasee LV– Phase IIINational Wide Area Measurement System
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Characteristics Improve the national system coverage 14 universities involved West BIPS monitoring
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Source: www.medfasee.ufsc.br/temporeal
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HVPMS(High Voltage Phasor Measurement System)– The HVPMS resulted from a
partnership with Eletrosul, a transmission utility in Southern Brazil
– Four PMUs, installed at Ivaiporã, Areia, Campos Novos and Nova Santa Rita 525 kV substations
– Voltage and current phasors are sent to the PDC at a rate of 60 data frames per second
– It has been monitoring eight transmission line terminals with two transmission lines having PMUs in both terminals
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MedFasee Project EletrosulPMUs
Digital Fault Recorder with PMU functionality
2 RPV 304 + 2 RPV 310 Standard IEEE C37.118 Rate 60 phasor/second - 3Ф Link Ethernet and UDP/IP protocol Configurable to 10, 12, 15, 20, 30 e 60
phasors/s e positive sequence
RPV 304
RPV 31037
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Projeto MedFasee Eletrosul PDC
Characteristics: PC architecture GNU/Linux + (RTAI) operational system Object Oriented Modeling (C/C++) MySQL Database
Features: Receiving, handling and re-
synchronization of phasors Centralized data available and storage Support for off-line analysis 15 days historical database
Hardware:• Core 2 Duo 3GHz• 2 GB RAM• 250 GB HD
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An event, on March 21, 2009, is used to illustrate the correlation between the LVPMS and the HVPMS
Event Description– 525 kV transmission line Lajeado-Miracema tripped;
– 900 MW generator shedding at Lajeado hydroelectric power plant;
Data Correlation(LVPMS X HVPMS)
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LVPMS x HVPMS(Frequency Behavior)
LVPMS HVPMS
High correlation between the recorded data
0 50 100 150 200 250 30059.7
59.75
59.8
59.85
59.9
59.95
60
60.05
60.1
Freq
uenc
y (H
z)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
UFPAUFCUnBUSP-SCUNIFEIUFRJUFSC
0 50 100 150 200 250 30059.7
59.75
59.8
59.85
59.9
59.95
60
60.05
60.1
Freq
uenc
y (H
z)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
IvaiporãAreiaN.S.Rita
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LVPMS x HVPMS(Angle Difference and Power Flow)
80 85 90 95 100 105 11049.5
50
50.5
51
51.5
52
Ang
le D
iffer
ence
(Deg
rees
)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
80 85 90 95 100 105 1101090
1095
1100
1105
1110
1115
1120
1125
1130
Pow
er F
low
(MW
)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.02
0.04
0.06
0.08
0.1
0.12
0.14
Frequency (Hz)
Ang
le D
iffer
ence
Mag
nitu
de (D
egre
es)
0.37Hz
0.69Hz0.87Hz
0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Frequency (Hz)P
ower
Flo
w M
agni
tude
(MW
)
0.87Hz0.69Hz
0.37Hz
Angular Difference
UFSC (South) – USPSC
(Southeast)
LVPMS
HVPMS
Power FlowTL Ivaiporã-
AreiaFrequency SpectrumIvaiporã is an Interconnection point between
Southern and Southeastern regions
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BIPS Blackout(November 10, 2009)
– At 10:13:06 (PM), local time, the three 765 kV (AC) transmission lines that connect ITAIPU power plant to the BIPS tripped
– The fault was caused by a sequence of three single-phase short-circuits in different phases, near Itaberá substation
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Itaipu real time operation
BIPS Blackout(November 10, 2009)
The Itaipu power plant was operating with 18 generators, with a 5560 MW power flow over the AC link and a 5329 MW power flow over the HVDC transmission system
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Sequence and consequences of the Blackout
BIPS Blackout(November 10, 2009)
Disconnection of the Itaipu AC transmission system Overloading and tripping of transmission lines interconnecting
the Southern and Southeastern subsystems After two seconds, a cascating outage of power plants and
transmission lines in the Southeastern region led to a voltage collapse and the tripping of the HVDC link
The disturbance spread to other parts of the BIPS The blackout resulted in the interruption of approximately 25
GW, 40% of BIPS total load
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Recorded by the LVPMS– Voltage dipping, following the outage of the Itaipu AC
transmission system and the South-Southeastern interconnections.
BIPS Blackout(November 10, 2009)
185.5 186 186.5 187 187.50.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
Vol
tage
(PU
)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPAUNIFEIUnBCOPPEUSP-SCUTFPRUFSCPUC-RS
Voltage Collapse
Southeastern subsystemUSP-SC, COPPE and UNIFEI
The voltages recover in the South (PUCRS,
UFSC and UTFPR)
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BIPS Blackout(Recorded by the LVPMS)
180 200 220 240 260 280 300 32058
59
60
61
62
63
64
Freq
uenc
y (H
z)Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPAUnBUTFPRUFSCPUC-RS
Electromechanical oscillations
180 200 220 240 260 280 300 3200.9
0.95
1
1.05
1.1
1.15
1.2
Vol
tage
(PU
)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPAUnBUTFPRUFSCPUC-RS
Frequency excursions after the outage of the main South-Southeast interconnection
Voltage
HVPMS – Active Power Flow
180 200 220 240 260 280 300 320-1000
-500
0
500
1000
1500
2000
Pow
er F
low
(MW
)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
The 525 kV transmission line (Assis–Araraquara) keeps the Southern and Southeastern regions connected for 1min20s
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Asynchronous operation
BIPS Blackout(Recorded by the LVPMS )
LVPMS – Zoom in asynchronous operation
186 188 190 192 194 196 198 200 20258
59
60
61
62
63
64Fr
eque
ncy
(Hz)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPAUnBUTFPRUFSCPUC-RS
63.6 Hz (Max)South
58.6 Hz (Min)North
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First South-Southeast reconnection– At 01:43:50 (AM), the first attempt to reclose de
interconnection
BIPS Blackout(Recorded by the LVPMS)
Frequency Frequency Spectrum –North-South Mode
215 220 225 230 235 240 245 250 255 260 26559.94
59.96
59.98
60
60.02
60.04
60.06
60.08
60.1
Freq
uenc
y (H
z)
Time (seconds) - Start: Nov. 11, 2009 01:40:00 (local time)
UFPAUNIFEIUnBUTFPRUFSCPUC-RS
0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
1
2
3
4
5
6
7
8x 10
-3
Frequency (Hz)
Freq
uenc
y M
agni
tude
(Hz)
UFPAUNIFEIUnBUTFPRUFSCPUC-RS
0.25Hz
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The data captured by the both systems were very important to elucidate the Brazilian Blackout
Since than, the National System Operator have been use the Medfasee data to post-mortem disturbance analysis– Decrease the time spend in post-mortem analysis
BIPS Blackout(November 10, 2009)
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Selected Applications
Low-frequency oscillation mode detection Model Validation Transmission Line Parameters Calculation Small-signal control
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Model ValidationSelected Study
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BIPS disturbance 04/07/2009
Registers: MedFasee LV MedFasee Eletrosul
Simulation Model: Anatem/CEPEL
Validation Analysis Qualitative Validation Quantitative Validation
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Qualitative ValidationFrequency Signal Assessment
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Medição - BT
Simulação - BT
0 1 2 3 4 5 6 7 8 9 10
59
59.2
59.4
59.6
59.8
60
Frequência medida SPMS BT
Freq
uênc
ia (H
z)
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
UnBUFC USP-SCPUC-RS
0 1 2 3 4 5 6 7 8 9 10
59
59.2
59.4
59.6
59.8
60
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
Freq
uênc
ia (H
z)
Frequência simulada SPMS BT
UnB - (B.SUL)UFC - (Fortaleza)USP-SC - (São Carlos)PUC-RS - (Porto Alegre)
0 1 2 3 4 5 6 7 8 9 10
59
59.2
59.4
59.6
59.8
60
Frequência medida SPMS AT
Freq
uênc
ia (H
z)
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
IvaiporãCampos NovosNova Santa Rita
0 1 2 3 4 5 6 7 8 9 10
59
59.2
59.4
59.6
59.8
60
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
Freq
uênc
ia (H
z)
Frequência simulada SPMS AT
IvaiporãCampos NovosNova Santa Rita
Measured Simulated
LV
HV
EEL / UFSCReal Time Spectral Analysis
53
MDF Real-time applications Off-line applications
EEL / UFSCConclusions The MedFasee project involves the development of equipment,
installation, operation and performance analysis of Wide Area Measurement System (WAMS)
It is possible to get important information on the power system dynamic performance from the low-voltage WAMS.
The MedFasee project has been a rich experience and has contributed to the development and dissemination of WAMS technology in Brazil .
The WAMS represents a paradigm change in the power system monitoring
The WAMS measurement process must be simple and understandable for power system engineers
Improve the application of signal processing techniques in power system
EEL / UFSCThank you! Daniel Dotta
– Department of Electrical Engineering – EEL– Federal Institute of Santa Catarina – IFSC– E-mail: [email protected]– RPI contact– E-mail: [email protected]– Linkedin– http://www.linkedin.com/pub/daniel-dotta/11/79a/85b