eel / ufsc the brazilian wide area measurement system – experience and applications daniel dotta...
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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
EEL / UFSC
To present an overview of the Brazilian
experience with Wide Area Measurement
Systems
Objective
EEL / UFSC
Wide Area Measurement System - WAMS
EEL / UFSC
Wide Area Measurement SystemOverview
5
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 t
XX
X
6
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!
EEL / UFSC
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)
8
EEL / UFSC
By SCADA By WAMS
How can the power system be seen?
9
EEL / UFSC
Phasor Measurement Process
EEL / UFSC
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 (
pu)
Time-Domain Signal
1/fs
N=12
12N
Sampling period1
ss
Tf
Regular sampling period (Ts)
12 60 720sf Hz 0.0014sT s
EEL / UFSC
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 N
N
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 (
pu)
Time-Domain Signal
1/fs
N=12
12N
EEL / UFSC
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
21
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
EEL / UFSC
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)
EEL / UFSC
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 size
w – actual frequency
w0 – nominal frequency
truemesX PX
00
( )( 1)
2
0
( )sin
2{ }( )
sin2
tj N
N t
P et
N
Phasor correction
EEL / UFSC
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
EEL / UFSC
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
Ma
gn
itud
e (
pu
)
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)
Fre
quen
cy (
Hz)
Signal Frequency
EstimatedReal
EEL / UFSC
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 (
pu)
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
EEL / UFSC
MedFasee Project
EEL / UFSC
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
EEL / UFSC
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
EEL / UFSC
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
EEL / UFSC
PMU UTFPR
PMU PUC – RS
PMU e PDC LabPlan – UFSC
MedFasee Project – Low VoltagePrototype Installation Details
25
EEL / UFSC
a) Frequency Evolution: b) Frequency Spectrum
System frequency oscillation mode ~ 0,02 Hz (period
50s).
Frequency Monitoring (12/01/2005) 15h00min00s e 15h29min59s)
EEL / UFSC
Firsts Disturbances Disturbance Southeast / Mid-West (14/03/2005 – 05h05min12s)
EEL / UFSC
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
28
EEL / UFSC
Source: www.medfasee.ufsc.br/temporeal
EEL / UFSC
PMU UFSC – Florianópolis, SC– Installation Date: 30/11/2008
MedFasee LV - Installations
30
EEL / UFSC
PMU UFPA, Belém, PA– Installation Date: 06/11/2008
31
MedFasee LV - Installations
EEL / UFSC
COPPE/UFRJ, Rio de Janeiro, RJ– Installation Date: 18/12/2008
32
Phase II -> Conclusion
MedFasee LV - Installations
EEL / UFSC
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
33
EEL / UFSC
MedFasee LV– Phase IIINational Wide Area Measurement System
34
Characteristics Improve the national system coverage
14 universities involved
West BIPS monitoring
EEL / UFSC
Source: www.medfasee.ufsc.br/temporeal
EEL / UFSC
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
EEL / UFSC
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 310
37
EEL / UFSC
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
38
EEL / UFSC
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)
EEL / UFSC
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
Fre
quen
cy (
Hz)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
UFPAUFC
UnB
USP-SC
UNIFEI
UFRJUFSC
0 50 100 150 200 250 30059.7
59.75
59.8
59.85
59.9
59.95
60
60.05
60.1
Fre
quen
cy (
Hz)
Time (seconds) - Start: March 21, 2009 12:20:00 (local time)
Ivaiporã
Areia
N.S.Rita
EEL / UFSC
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
(D
egre
es)
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
(M
W)
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 (
Deg
rees
)
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
(M
W)
0.87Hz0.69Hz
0.37Hz
Angular Difference
UFSC (South) – USPSC
(Southeast)
LVPMS
LVPMS
HVPMS
HVPMS
Power FlowTL Ivaiporã-
Areia
Frequency SpectrumIvaiporã is an Interconnection point between Southern and Southeastern regions
EEL / UFSC
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
EEL / UFSC
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
EEL / UFSC
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
EEL / UFSC
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
(P
U)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPA
UNIFEIUnB
COPPE
USP-SC
UTFPRUFSC
PUC-RS
Voltage Collapse
Voltage Collapse
Southeastern subsystemUSP-SC, COPPE and UNIFEI
The voltages recover in the South (PUCRS,
UFSC and UTFPR)
EEL / UFSC
BIPS Blackout(Recorded by the LVPMS)
180 200 220 240 260 280 300 32058
59
60
61
62
63
64
Fre
quen
cy (
Hz)Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPA
UnB
UTFPRUFSC
PUC-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
(P
U)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPA
UnB
UTFPRUFSC
PUC-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
(M
W)
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
EEL / UFSC
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
64F
requ
ency
(H
z)
Time (seconds) - Start: Nov. 10, 2009 22:10:00 (local time)
UFPA
UnB
UTFPRUFSC
PUC-RS
63.6 Hz (Max)
South
58.6 Hz (Min)
North
EEL / UFSC
First South-Southeast reconnection– At 01:43:50 (AM), the first attempt to reclose de
interconnection
BIPS Blackout(Recorded by the LVPMS)
FrequencyFrequency 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
Fre
quen
cy (
Hz)
Time (seconds) - Start: Nov. 11, 2009 01:40:00 (local time)
UFPA
UNIFEI
UnBUTFPR
UFSC
PUC-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)
Fre
quen
cy M
agni
tude
(H
z)
UFPA
UNIFEI
UnBUTFPR
UFSC
PUC-RS
0.25Hz
EEL / UFSC
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)
EEL / UFSC
Selected Applications
Low-frequency oscillation mode detection
Model Validation
Transmission Line Parameters Calculation
Small-signal control
EEL / UFSC
Model ValidationSelected Study
51
BIPS disturbance 04/07/2009
Registers: MedFasee LV MedFasee Eletrosul
Simulation Model: Anatem/CEPEL
Validation Analysis Qualitative Validation Quantitative Validation
EEL / UFSC
Qualitative ValidationFrequency Signal Assessment
52
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
Fre
quên
cia
(Hz)
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
UnB
UFC USP-SC
PUC-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)
Fre
quên
cia
(Hz)
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
Fre
quên
cia
(Hz)
Tempo(s) - 04/07/2009 - 18:36:37,15 (Local)
Ivaiporã
Campos 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)
Fre
quên
cia
(Hz)
Frequência simulada SPMS AT
Ivaiporã
Campos NovosNova Santa Rita
Measured Simulated
LV
LV
HV
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]
– http://www.linkedin.com/pub/daniel-dotta/11/79a/85b