iii workshop pmu coppe2 - kth · centro de pesquisas de energia elétrica - cepel título do...

Centro de Pesquisas de Energia Elétrica -CEPEL

Título do trabalho

Centro de Pesquisas de Energia Elétrica - CEPEL

III International Workshop

on PMU Applications:

Perspectives for ONS and Transmission

Centro de Pesquisas de Energia Elétrica - CEPEL III WORKSHOP on the Use of Synchrophasors | 11 2014

Autor/apresentador

Área

Título do trabalho

Raul B Sollero

Systems Automation Department - DAS

Perspectives for ONS and Transmission

Owners in Brazil

COPPE/UFRJ

Outline:

Motivation - the Brazilian regulatory framework

Applications considered by Brazilian Transmission Owners –

the Eletrobras Workshop


the Eletrobras Workshop

Applications selected by ONS – the RFI

Ongoing initiatives at Cepel

Present situation in Brazil

MEDFASEE

Partnership UFSC/Reason/FinepPMUs in the system today

Individual initiatives from some

companies

� Chesf

� Furnas

� Eletronorte


� Eletrosul, …

Universities - Medfasee

ONS - SMS (Aneel Resolution 170/2005)

� ONS RFI for Phasor Data Concentrators

and applications for the Synchrophasor

Data Network project

ONS Responsibilities

Define and specify the architecture of the

Phasor Measurement System and

telecommunication requirements �

Reassess requirements, quantities and

location of the Phasor Measurement Units -

Motivation

ANEEL Resolution -170/2005


location of the Phasor Measurement Units -

PMUs to be installed by the agents �

Coordinate the PMU Certification process,

through independent laboratory tests (in a

first phase no PMU was certified) �

Specify, acquire and install the ONS' Phasor Concentrators

Define PMU placement

Define the schedule and coordinate the PMU installation by TOs

Motivation

ANEEL Resolution -170/2005

Transmission Companies responsibilities

To purchase, install, operate and maintain the PMUs placed in their substations

To supply the communication links to ONS’ PDCs, complying with technical

requirements, specifications and schedules coordinated by ONS.

(ONS letter 1468/100/2013, December 02/2013)


Counterpart

Operation and maintenance costs considered after ANEEL audit, at the periodic

revisions on the permitted annual revenue, on the tariffs or costs

Access to the measurements data

How can Transmission Companies benefit from ONS’s infrastructure?

Model of the Brazilian Electric SectorApplications of interest for ONS

ONS is a not-for-profit organization whose mission is to operate the Brazilian

Interconnected Power System in an integrated manner, seeking security, continuity and

economicity of electricity supply in the country

So: phasor applications of interest to ONS should aim at:

Reduction of the risks of power outages

� Enhance the system observability and situational awareness


� Enhance the system observability and situational awareness

� Monitor and alarm at potentially unsafe states or events (oscillations, suden changes,..)

� Prevent cascading events

� Wide area monitoring and control: protect the power system grid as an entity

Increase the quality and efficiency of electricity service

� Support tools to minimize restoration and reconfiguration times

� Disturbance detection and location tools

Model of the Brazilian Electric SectorApplications of interest for the Transmission Owners

Transmission companies are remunerated by the full availability of their assets,

regardless of the amount of energy transmitted through their lines

So: Phasor applications of interest to the transmission companies should aim at:

Maximization of the availability of their assets

� To reduce the risk of equipment failure or minimize its impact

� To increase the reliability and performance of their protection systems (equipment and systems)


� To increase the reliability and performance of their protection systems (equipment and systems)

� To reduce restoration times after a disturbance…

More efficiency and reduction of operational costs

� Better disturbance analysis tools - higher efficiency in fulfilling regulatory requirements and to

avoid undue penalties

� Monitoring of conditions that can lead to overvoltages, overloads and other stressful situations in

their equipment, with an impact on the degradation on their life cycle…

• Disturbance Analysis

Operational efficiency

Mapping the key phasor applications to TOs: Eletrobras

Companies Workshop

Agenda


• Disturbance Analysis

• Fault Location

• Line parameters calculation and validation of network simulation tools

• Out-of-step detection

• Differential protection – lines, busbars

• Wide area backup protection

Availability of assets

Disturbance analysis and protection

performance analysis

Objectives� To reconstruct the sequence of events post disturbance� Considered one of the most useful applications for a

synchrophasor infrastructure

Benefits� Less time and effort for the analysis� Avoids undue penalties� Enhances reliability


� Enhances reliability

Tecnology� Sufficient number of PMUs for the function� Archiving of local data� Perspective for evolution to a Smart Analyzer, capable

to process data from multiple sources (fault recorders, relays, PMUs, ..)

Gap� No product such as a Smart Analyzer

Source: MedFasee

Fault location

Objectives� To improve accuracy on the establishment of the point of incidence of faults –

permanent or transient

Benefits� More accuracy on fault location translates to shorter restoration times� Fault location can be sent to the maintenance teams within milliseconds from the

event.


Technology� Voltage and current phasors at both terminals of

the transmission line� Communication links with permanent

availability� Available algorithms (Johns & Jamalis, ..)

Challenges� Extraction of information from a small

window

Line impedance calculations

Objectives� Dynamically calculate positive and zero sequence line impedances from measured

quantities at line terminals

Benefits� Inaccurate values for calculations derived from line constants (mainly for zero

sequence): influence on distance relays operation� A study of the zero sequence impedance variation based on the season of the year

could be made (use of different setting groups)


Challenges� Positive sequence impedance: can be obtained at any time with positive sequence

measurements at both ends of the line� Zero sequence impedance: can only be obtained when a fault occurs on the line

Validation of network simulation tools

Objectives� To validate network simulation tools using data obtained during power system

disturbances

Benefits� More reliability and confidence on protection settings; better use of available

capacities; more confidence on off-line simulation tools

Tecnology


Tecnology� PMUs distributed at the network

Challenges� Basic technology already available

Comparison between calculated

and measured currents during a

disturbance in India

Out-of-Step detection logic enhances distance

relays stability

Objectives� Improve the ability to detect power swings, to separate the system under

unstable power swings and to avoid undue zone 3 protection operations

Benefits� More robustness of the system under disturbances:

o Avoids spurious tripping of zone 3 during oscillationso Avoids refusals of operation for three-phase faults

during oscillations


during oscillationso Controlled separation under unstable power swings

Technology� Continuous monitoring, through PMUs, of the variation of:

o Angles of the busbars positive seq. voltageso Apparent Power (S) absorbed by the transmission lines

Challenges� To demonstrate reliability� Operating times limit

application to zone 3

Equipment: line differential protection

Distributed generation: complex configurations

Backup for GPS signaling: local atomic clocks?


Ref: Alex Apostolov

Equipment protection: Busbars

Possible architecture for busbar differential protection


Wide area backup protection using

synchrophasors

Function� Differential backup covering multiple zones, dynamically redefinable

Benefits� Selectivity and faster operating times

� Stability under oscillations and heavy loads

� Unnecessary coordination settings


� Unnecessary coordination settings

� Fewer hidden faults: auto monitoring for

communication, equipment and measurements

Gap� Availability and latency of communication systems

� Cyber security

� Traditional challenges: CT saturation, complex busbar arrangements, shunt reactances. ..

• Plot charts for every measurement made by the SMS

• Spectral Analysis

• Modal Analysis

Network Analysis Applications – Situational Awareness

ONS Request for Information – RFI

Agenda


• Modal Analysis

• Event Analysis

• Monitoring of frequency, voltage, angle, power

• Oscillatory Stability Monitoring

• Restoration Support

• Disturbance Detection and Location

Network Real-Time Applications - Security

ONS Synchrophasor Measurement System(Source: ONS)

31 Substations, 181 Line Terminals

543 phase voltage and 724 phase current

synchrophasors

1 second total latency time

Dedicated telecommunication channels to

guarantee bandwidth and system security


guarantee bandwidth and system security

Phasors in real time using multicast

addressing and C37.118 format

ONS to hire telecom provider to the RDS

point of presence

All accesses are redundant

Power System Monitoring:

Better situational awareness of the network

Function� Real time display of current profile, maximum & minimum values and deviations

from expected for:� Frequency

� Voltage

� Angle

� Power flow (active and reactive)

Benefits


Benefits� Faster and more effective situational

awareness

� Each unexpected variation can be

correlated with EMS alarms

Gap� Selection, establishment of limits and form of presentation of the most significant quantities

Ref: CAISO

Detection of poorly damped local and inter area oscillations

Functions and Objectives� To alarm the occurrence, to identify the vectors representing the amplitude and

phase (mode shape) for local and inter-area oscillations

� Display mode damping, mode amplitude and mode phase for each mode

� Display the group of measurements which are oscillating in phase or out of phase.

Benefits� Unstable oscillatory modes can rise and result in system breakup and blackouts


� To identify flaws in control systems

Tecnology� High rate PMUs (Nyquist)

� Phase angles at generator voltage terminals

and positive sequence voltages

� Frequency analysis (Prony or Wavelets, per ex.)

Gap� Discriminating oscillations from noise is

challenging

Detection of poorly damped local and inter area oscillations


Compass plot

� Vectors indicating the amplitude

and phase of signal oscillation

Bar plot

� Bars indicating the amplitude

and frequency of signal

oscillation

Source: Siemens

Power System restoration support

Function� To support the Operator for faster and safer restoration

� Real time identification and alarm of an islanding condition

� Display of voltages, frequencies and angular differences in different islands

Benefits

� Time efficiency

� The Operator knows whether it is feasible to


� The Operator knows whether it is feasible to

command the tie breaker

� Close monitoring of the state of the system

during the restoration process

� Valuable resource to alleviate the Operator

stress during a restoration

Gap

� Operator’s simulator training is advisable

� Simulators need to offer information that emulates direct measurements

Black-start training at WECC

Disturbance Detection and Location

Function� Detect and display in real time a

disturbance occurrence

� Suggest the type of disturbance :� generation trip

� load shedding

� transmission line tripping

� Cascading failure


� Based on all available signals,

pinpoint the most likely geographical

disturbance location

Benefits� Situational awareness enables fast countermeasure actions

Gaps� Large scale events are, typically, very complex

Roles and responsibilities of CEPEL

Some ongoing initiatives


Some ongoing initiatives

Cepel’s SAGE is the most prevalent SCADA/EMS

system in the Brazilian transmission network

Sage provides the real-time solution to REGER – the

set of 4 integrated SSC’s that support ONS

operation of the whole Brazilian Interconnected

Power System

Cepel as a provider of tools for the Operation of the Brazilian Electrical Network


The Reger contract includes Control Center phasor

applications, to be driven by the planned ONS

Synchrophasor Network

SAGE/EMS:

• +100 clients

• + 700 installations in Brazil

Cepel’s SAGE is the most prevalent SCADA/EMS

system in the Brazilian transmission network

Sage provides the real-time solution to REGER – the

set of 4 integrated SSC’s that support ONS

operation of the whole Brazilian Interconnected

Power System

Cepel as a provider of tools for the Operation of the Brazilian Electrical Network


The Reger contract includes Control Center phasor

applications, to be driven by the planned ONS

Synchrophasor Network

Personnel and hardware infrastructure for

engineering, communication, cybersecurity,

maintenance, updates and so on, for Sage, is fully

operational and reaches hundreds of installations

Transmission companies are now seeking the best alternative to make use of the phasor data

obtained from their substations to be sent to ONS

SAGE EMS applications included in the ONS

REGER system

Real Time Network Analysis Tools

Equipment Outage

scheduling

Topology Processor

Parameter Adaptation

State Estimator

SimulationStudy Mode

Operator

Powerflow

Optimal

Powerflow

Contingency

Analysis

Network

GenerationControl

Automatic Gen

Control

Reserve

Monitoring

Deviation

Monitoring

Generation

Rescheduling

SynchrophasorApplications

Stress

Monitor

Sync Assist

Loop Assist

Damp Mon

3rd Party

Integration

Siemens

PowerCC IMM

Historian

OSISoft PI

Epri

OTS


Topology Estimator

Contingency Analysis

Remedial Action

Automatic Voltage

Control

Constrained Dispatch

Network

EquivalentsRescheduling

Production Production

Schedulling

AGC Monitoring

Economic Dispatch

Production Costs

Load Forecast

Damp Mon

Innovative approach: enable SAGE for PDC capability,

eliminating the need for another local infrastructure!

SAGE Phasor Applications

Sage/EMS as a local Phasor Data Concentrator (PDC)

• Full support do IEEE C37-118 protocol for direct communication with PMUs and distribution to external PDCs, at native rates (say, 60 samples/s)

• SCADA phasor data distribution through ICCP

• Platform for processing local applications

SOM – Monitoring Power System Oscillations


• DampMon – Evaluation of mode shapes of system oscillations

VPAM – Monitoring of Voltage Phase Angles

• StressMon – Monitoring of system stress

• SynchAssist – Resynchronizing electrical islands

• LoopAssist – Closing a transmission system loop

EMS – Including synchrohasors into the Power System State Estimator

• SE – Merge direct phasor measurements to enhance state estimation

SAGE as a substation PDC


� Small signal instability is one of the major threats to grid reliability in some systems

� An unstable oscillatory mode can cause large-amplitude oscillations and may result in system

breakup and large scale blackouts

An oscillation may be triggered by:

Phasor Measurements Applications

DampMon

� Small disturbances during heavy

power transfers between areas

Bad behavior of control systems


� Bad behavior of control systems

� Application input: the complete set

of samples (60 s/sec)

StressMon - Monitoring Transmission Loading

Monitors angle difference between pairs of locations or

regions in the power system

Alerts on sudden angle-pair changes for critical corridors

Phasor Measurements Applications -StressMon


Barra X Barra Y

VX

VY

PX-Y

QX-Y

Área AÁrea B

-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-10

0

15:05:0015:32:0015:44:0015:51:0016:05:0016:06:0116:09:0516:10:38Time (EDT)

Rel

ativ

e P

hase

Ang

le

Cleveland West Michigan

Normal Phase Angle is approx. -25º

Phase

Angles

Diverg

ed

Prior

To

Blacko

ut

August 14, 2003 Blackout

Phasor Measurements Applications -StressMon


f=59.95 Hz

Phasor Measurements Applications -SyncAssist

Phasor

Time curve frequency

differences

Ref: main system f

SyncAssist - Assistance on Reconnecting Islands

Monitors voltage magnitude difference, angle difference and frequency deviation across transmission

equipment involved in reconnecting electrical islands

To guide the operator on conditioning the power system for a valid reconnection situation


BarraY

Bus B

(PMU)Main system Island

Bus A

(PMU)BarraX

VA

VX

VB

VX

VY

VA

VB

VAB

Phasor

Diagram

Ref: main system f

Time curve with voltage

differences VAB

Time curve with angle

differences

Assistance on Closing Transmission Loops

Monitors voltage magnitude and angle difference across circuits involved in closing

transmissions loops in the power system

Means to guide the operator on conditioning the power system for a valid reconnection

situation , minimizing impacts on existing equipment.

Phasor Measurements Applications -LoopAssist

Phasor

DiagramOpen Loop


Bus A

(PMU)

Barra X

Bus B

(PMU)

Barra Y

VA

VB

VX

VY

Diagram

Time curve with angle

differences

Time curve with voltage

magnitude differences VAB

Open Loop

SE uses SCADA data to determine (every few seconds) a ‘best estimate’ of the current

power system state:

Voltages, Angles, MW/MVAR flows, CB status, taps, etc

SE has become a critical, ‘must-run successfully’ control center function. Provides input

to:� Contingency Analysis

� Remedial Action

� Constrained dispatch, …

State Estimation (SE)


� Constrained dispatch, …

One of the key solution variables in SE is the:

bus voltage phase angle

PMUs can now provide the direct

measurement of voltage phase angle as well as

current phasors:� Better observability of the network� Enhanced accuracy� More robustness

Candidate approaches for SE in consideration

for SAGE

Candidate approaches

� Hybrid SEs: SCADA and PMU data processed simultaneously – internal change

� Multistage approaches: separate processing – parallel or sequential

� Evolutionary solution ( Multistage approach) was selected for SAGEo Preserves current implementation and installationso Strategy defined after a master thesis at Coppe – Prof. Djalma Falcãoo Yet under analysis: A Priori Information or State Estimate Fusion approaches


A priori information approach Fusion approach

Cepel’s Synchrophasor Measurements

Laboratory - LabPMU

Foreseen activities

Reference tests: accuracy, performance, compatibility, ..

Research: platform to test and validate synchrophasor applications (internal or

external)

Support to field installations: real life


Support to field installations: real life

challenges (synchronization,

communication, latency, ..),

Exploring new possibilities: harmonics

Platform for testing and validating

synchrophasor applications


Output files from ANATEM

Comments?

Contributions?

Thanks!


Raul B Sollero

[email protected]

Centro de Pesquisas de Energia Elétrica - CEPEL

iii workshop pmu coppe2 - kth · centro de pesquisas de energia elétrica - cepel título do...

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