Data Analytics with a Real Time Monitoring System

- WAM System & SCADA System

Walter Sattinger C2.18

Web – 10th November 2020

1. Why SCADA / EMS Systems will have to be expanded?

2. Challenges and Application Examples

3. Realisation Approaches

4. Barriers and Possible Solutions

5. WAM System Integration Approaches

6. Conclusions & Expected Future Developments

7. References

Table of contents

1.1 Why SCADA / EMS Systems will have to be expanded?

Power system operation is becoming more complex due to an increasing number of impacting stakeholders

Generation pattern is in transition due to the required decarbonisation process

Power system size and structure is changing permanently

Interconnected operation with distributed responsibility is required

New tools and approaches will have to be considered

1.2 Current and Future Challenges – New Energy Sources

4

demand-side

management

increase of

efficiency

nuclear power

exit

subvention of

renewable

generation

market

opening

decarbonisation

2.1 Continental Europe Example – Increase of System Size

5) 2010 - synchronisation of Turkey+ 50 GW + 1800 km to east

Each system expansion step

required analysis, especially for

dynamic stability

Risk of poorly damped inter-

area oscillations

New technologies allow for a

permanent monitoring of system

stability today

Next system expansion steps:

• Baltic states

• Ukraine & Moldavia

2.2 Continental Europe Example – Current Structure

2000 x 4200 km / 400 GW 26 Countries30 Transmission system operators530 Mio inhabitants220 - 440 GW system load

2.3 Impact of Different Stakeholders Behaviour –Deterministic Frequency Deviations

positive control power deviation

negative control power deviation

load ramp

Schedules for BRP & power plants

2.4 System Connection Monitoring – UCTE Power System Resynchronisation

ZONE 2

ZONE 1

PMU

PMU

Peak Load: 223 GW

Peak Load : 21 GW

PMU

PMU

2004 October 10th

9:34 – 10:58

Zagreb

European Electrical Reunification

5 x 380 kV

2 x 220 kV

1 x 110 kV

2.5 System Connection Monitoring

On

-lin

e-M

on

ito

rin

g o

f syste

m d

am

pin

g b

eh

avio

ur

3.1 Difference between SCADA and Phasor Approach

3.2 WAM Data Acquisition Approach

CommunicationSwitchgear Cubicle-PMU Data Concentrator

Current & Voltage

Phasor

Frequency

Accuracy

0.1 Degree

1 mHz

Time Resolution

20 msec

Substation

Feeder

VT, CT

Data Export

Alarms

Informa-

tion

Filter

SCADA

System

Combined use of both

technologies

Powerful tool for on-line

and off-line analysis

Time-aligned datasets

already during acquisition

available

Latency: 40-100 ms

3.3 History of Continental Europe WAM Setup – SG Example Connections

ATATÜRK

HES TM

TEMEL

Lİ TM

HAMİTAB

AT TM

Kasso

Recarei

HamitabatTemeliAtatürk

Participation in CE system

extension projects have created

the conditions required for a CE

WAM overview system

Start of WAM activities in 2003

as a pilot application

3.4 Key Messages – Main Applications Feedback

Crucial role of reliable telecommunication

Efficient use only by wide system data exchange

Clear rules and standards for data exchange including separation of market sensitive information data exchange

Example: Turkey island operation 2019, April 23nd, 9:03-9:39 CEST

0

0.05

0.1

0.15

0.2

0.25

0.3

00:00:00 04:00:00 08:00:00 12:00:00 16:00:00 20:00:00 00:00:00

Hz

Oscillation Freqency - Voltage Phase Angle: Mettlen - Ag. Stefanosxx

xx

3.5 Monitoring Application Examples

Oscillation Analysis

• Frequency ranges 0.002 Hz to 50 Hze.g. governor, electromechanical, control, power electronics & series capacitor

• Mode shape, coherence & source location

• Control tuning

Disturbances

• Frequency & angle disturbances – location & impact

• Islanding and resynchronisation

Model validation

• Dynamic models – transient & small signal

• Loadflow – line parameters, state estimator

Post event analysis & reporting

3.6 Monitoring & Control Timescale

15 minutes

Operator Dispatch

Human Response

3-15 s

Automated

Dispatch

200-600 ms

Wide-Area Defence

16-200 ms

Equipment

Protection

0.6-3 s

Automated

Trip

Automated Wide Area Control Control Room EMS/WAMSProtection

Local & Differential Fault Protection

Short-Term Voltage Stability

Long-Term Voltage Stability

Oscillatory Stability

Frequency Stability

Transient Stability

N-x Transient Stability

3.7 Monitoring OscillationsMany forms of oscillation over wide frequency range

Common-mode(0.005-0.1 Hz)

Electromechanical • Inter-area (0.1-1.0 Hz)• Local (0.7-2.0 Hz)

Modal Interaction• Electromechanical• Sub-Synchronous

Resonance

Voltage control mode

(1.5-6 Hz)

Power electronics(e.g. HVDC)

Out-of-Step

Periodic ForcingHydro rough-

runningWater column

oscillations

Very Low FrequencyCommon Modes

0.002 Hz

0.1 Hz

4 Hz

Electromechanical

Control modes

Rough running

Power electronic control modes

Sub-synchronous oscillation/resonance

12 Hz

46 Hz

Sta

ndard

PM

UEx

tend

ed r

ang

e

Group 1 ContributionsGroup 2 Contributions

3.8 Conclusions on Managing Oscillations

Many oscillation issues exist in Europe needing co-ordinated response

High level sparse PMUs can show Alarm on occurrence of large / poorly damped oscillation

Participating regions

Region(s) contributing to problems - where action helps

Detailed own-system PMU system can show Specific areas, plants or corridors of interest

Guidance for how to resolve in real-time or long-term

Long-term trends and risk assessments

All sizes of system or interconnection need oscillation risk management

3.9 Iberic Peninsula Oscillation on Sept. 1st 2020

Iberian mode dominant

over hours

One ES-FR 400 kV line

out of operation

Significant export from

Iberian peninsula to the

centre of the CE

system (higher 2 GW)

0.18 Hz mode

Up to 70 mHz peak-to-

peak

3.10 Current CE Power System Behaviour – WAM / SCADA View 1

3.11 Current CE Power System Behaviour – WAM / SCADA View 2

3.12 Current CE Power System Behaviour – WAM / SCADA View 3

3.13 Phase Angle Monitoring and Constraints

Transient and oscillatory stability constraints more closely related to angle difference than power

Power cut-set constraint on long corridor with infeeds (e.g. wind) changes with location of generation

Power-angle monitoring or constraint used as: Alarm on anomaly – large angle difference indicates

weakened network or long P transmission distance

Constraint definition as P&∆δ – closer to physical corridor dynamic limit than simple P cut-set

Phase angles can be useful in alarming and constraint management

δ

3.14 Black Start and Power System Restoration

PMU data is necessary to monitor the black start path

09:0

5:00

.000

09:0

5:50

.000

09:0

6:40

.000

09:0

7:30

.000

09:0

8:20

.000

09:0

9:10

.000

09:1

0:00

.000

09:1

0:50

.000

09:1

1:40

.000

09:1

2:30

.000

09:1

3:20

.000

09:1

4:10

.000

09:1

5:00

.000

09:1

5:50

.000

09:1

6:40

.000

09:1

7:30

.000

09:1

8:20

.000

09:1

9:10

.000

09:2

0:00

.000

09:2

0:50

.000

09:2

1:40

.000

09:2

2:30

.000

09:2

3:20

.000

09:2

4:10

.000

09:2

5:00

.000

09:2

5:50

.000

09:2

6:40

.000

09:2

7:30

.000

09:2

8:20

.000

09:2

9:10

.000

09:3

0:00

.000

09:3

0:50

.000

09:3

1:40

.000

09:3

2:30

.000

09:3

3:20

.000

09:3

4:10

.000

09:3

5:00

.000

09:3

5:50

.000

09:3

6:40

.000

09:3

7:36

.860

09:3

8:26

.860

09:3

9:16

.860

09:4

0:06

.860

09:4

0:56

.860

09:4

1:46

.860

09:4

2:36

.860

09:4

3:33

.220

09:4

4:23

.220

In black start, operators must immediately see success and stability of each stage in the black start plan.

Any failure to energise or resynchronise must be observed immediately and addressed correctly.

Future use of renewable & distributed generation for black start requires close attention to dynamics.

WAMs accelerate restoration

and reduce exposure to risk

3.15 Power System RestorationDynamics and stability important in load pickup and resynchronising

3.16 Wide Area Control for Fast Frequency Response

Locational FFR improves grid stability, allows flexibility in resources, and reduces islanding

1

2

3

6 4

Zones Centres of inertia; islanding may occur between zones, not (successfully) within zones. A single Aggregated Angle and Frequency per zone shared with all control points. N

Frequency

System ROCOF Aggregated frequency from all connected zones system ROCOF*inertia MW loss.

Islanding detection: control uses connectedROCOF & inertia

Disturbance Frequency accelerates in proportion to (MW loss) / (inertia). BUT not uniform across network

Angles swing apart during disturbance islanding risk

Act in location to return angles to system mean angle

Mean angle

Angle Difference Frequency

5

3.17 Landsnet Smart Grid for Locational FFR

❶❷

❶ ❷ ❹

❸

Control Centre

• Data Concentrator for PMU data• Control Room visualisation• Administration of PhasorControllers• Testing & trials

ISAL Smelter Load Control

• PhasorController• PMU data IN, 61850 GOOSE OUT• 1x interface unit to I/O plant control

Hrauneyjafoss (HRA) Fast Ramp

• PhasorController• PMU data IN, TPIO Digital Out• Governor acts on RAMP DOWN

& WICKET GATE CTRL

East Iceland Fish Factory Load Shed (x6 plants)

• PhasorController• PMU data IN, 61850 GOOSE OUT to 6x satellite I/O• Factories link satellite I/O to load breaker

❸

n

PhasorController20ms Real-Time PMU-based logic controller with specialist WACS function

block library

❹

❻ NAL Smelter Load Control

❻

7

7 Geothermal governor control (planned)

5

5

3.18 Fast Frequency Response Resources Using Existing Generation and Load for Efficient Fast, Stabilising Frequency Services

System lossPower

Time

4-8 s

Frequency

Time

Instantaneous balance

Steady-state balance

(governor response finished)

Long term balance

(redispatch to market)

20-40 s

Rapid Event-Triggered Responses (Wide Area & Local)

Rapid Frequency-Proportion &

Deadband (Local)

Frequency-Proportion & Delay (Local)

Dispatch / Market

Kinetic Energy Accel/Decel

UNIFIED TOTAL POWER BALANCING RESPONSE USING DIVERSE RESOURCE

Frequency response resources co-ordinated for total frequency response. Rapid event-triggered (k1*∆Ploss) Rapid freq-control (k2*∆F; deadband) Normal freq-control (k3*∆F with delay)

Aggregation enables many diverse resources to participate in service provision, including variable generation & demand response

Delivering overall response that is: Proportionality to event Discriminating real system events Enhancing grid stability Predictable aggregate response

4.1 Barriers and Possible Solutions 1

Requirements:- high availability- independent of geographical/political events- no single technology- resilient to “adjustments” (i.e. leap seconds, reset of counters, …)- as immune as possible to weather conditions

Time synchronization

Absence of synchronization must be properly detected

Time synchronization is not completely reliable, because GPS is a militarysystem that might be switched off; different alternatives are under study(Galileo, GLONASS).

GPS signals can be spoofed or jammed -> Redundancy is required

Different solution on field: IEEE1588, IRIG-B, direct GPS receiver, …

4.2 Barriers and Possible Solutions 2

Recognition of a PMU losing synchronism

This event can cause a serious degradation of TVE and angle estimation. The erroneous or slow synchronismfault could endanger Special Protection Schemes based on angle difference monitoring or alarm generationbased on angle

During this real test, the PMU “resists” with TVE > 1%for about 40 minutes.

Under certain circumstances, some PMUs and PDCs do not recognize thesynchronism fault for several hours. Additional work on market products hasto be done to enable the transition to WADC.

4.3 Barriers and Possible Solutions 3

Telecommunication challenges

Cyber security issues

- Secure protocols- Firewalls- Segregation- Manage real time exchanges

between TSOs

Communication channels

- Low cost- Low latency and high determinism- Availability- High traffic management- Performances guaranteed

4.4 Barriers and Possible Solutions 4

Other challenges:

Multi-vendor base applications can lead to challenges whilst using visualization, oscillationmonitoring and events alarms tools, due to different precision for measured quantities.

Manage systems with several PMUs (selection of the signals, PDC, visualization tools etc.)

Improve the processing capabilities for post-mortem analysis

Training of the System/Grid Operator

Select information exchange between TSOs managing/filtering/encrypting data potentially sensitive for market

5.1 Applications: Control

Fast frequency responses proportional to the eventEstimation the actual resistance of conductors and mean real time temperatureDetect and successfully damp inter-area mode componentEmergency frequency control, voltage control, load shedding, system damping control, system isolation and restoration FACTS for the related damping control

FACTS application

5.2 Applications: Protection• Automatic Generation Shedding Schemes (AGSSs) are triggered by observing the positive-sequence voltage angle

difference between two transmission nodes when one of the parallel line is opened or closed (<100 ms)• IG-SIPS:

• on-line determination of the generator which is going to be tripped, • emergency stability control based on real-time response of the generators

• Fault location and impedance estimation using PMU• Under-frequency Load Shedding (UFLS) scheme and an Under-voltage Load Shedding (UVLS) scheme

5.3 Integration

TECHNICAL ISSUES

Corporate vs communication networks

Cybersecurity issues

• Data spoofing / manipulation

• Denial of service

• Malicious code injection

• “Man-in-the-middle” attacks

• Packet injection attack (“Sniffing”)

• Data validation (crosschecks, plausibility,

management of missing data, etc.)

• Big data approach and data analysis tools

• High availability on the application layer

• Convergence between SCADA and WAMs

NON TECHNICAL ISSUES

Operator’s acceptance and confidence:

The integration of WAM systems in the control room can only

be successful if operators are engaged in the development

phase, trained and committed to use new real-time applications

and data outside of ex-post analysis

Usability and capabilities of WAM system based control

applications

The Human-Machine-Interface (HMI) of WAM system control

room applications needs to provide operators with the

information they need, when they need it.

Missing regulatory aspects

5.4 Integration: Roadmap Approach 1

Facilitate the transition from an isolated WAM system infrastructure to an integrated production‐grade

operation application to support everyday operations in the control room

Improve leverage of the already deployed WAM system infrastructure to minimize the additional investment

while achieving the desired operational goals

Improve coordination of the use and enhancement of the existing WAM system (in terms of infrastructure,

applications and processes)

Analyse how the WAM system can help to improve real‐time operations, grid protection, automation and

control, in order to cope with the increasingly high level of renewable energy resources and growing reliability

requirements

Assist the management in approving further investments required for the full‐scale integration of WAM

system in the control room

5.5 Integration: Roadmap Approach 2

Benefits to markets

Reduced ancillary services

Reduced curtailment costs

Integration of distributed generation

Benefits to system operation

Risk mitigation – avoidance of widespread outages

Developments in protection

Enhanced detection of unusual systems disturbances

(e.g. oscillations, voltage instability)

Benefits to system planning / asset management

Reduced grid reinforcement costs

Benefits of more accurate system models

Benefits to interconnection analysis and understanding impacts

of high renewable penetration

Benefits to ex-post analysis

Benefits of faster and more certain analysis of events

BENEFIT MATRIX

5.6 Integration: Operator Training

Get familiar with power system dynamic phenomena, the new functionalities or metrics served by the WAM

system and how they are impacting during severe conditions in the grid.

Analyse past events of interest, in order to understand operator responses during those conditions.

Provide a comprehensive view across traditional (steady-state) SCADA/EMS applications alongside the new

WAM system based on dynamic performance information.

5.7 Integration with SCADA / State Estimator

Scheme of the data flow

State-of-the art and WAM

system data

communication structure

5.8 Architectures

• One central PDC data access point for

other utilities instead of connecting the

devices to a common network.

• Control access rights to the data

• Control the data that are provided to

other utilities by selecting the

synchrophasor data which are

transmitted to the clients

• Control the update rate for each client to

optimize communication bandwidth

Exchange data between

different utilities

6. Conclusions - Expected Future Developments

Supporting renewable energy transition. Increasing capacity for renewables. Managing risks.

Extending Wide Area Control & Protection use cases, methodologies, applications & testing

Locational fast frequency control, islanding management

Continuous damping & transient stability control

HVDC stability controls for AC support

WAMS/EMS Synergy: Deeper integration of WAM system with EMS, enabling co-ordinated alert/alarm viewing and

applications using multiple data sources.

Oscillation monitoring:

Improved operational procedures, training and guidance to harness real-time stability information

Extended range of frequencies for power electronic & SSR issues; needs new sampling software in PMUs

Data Analytics: Machine learning to extract more information on grid dynamic performance and diagnostics. Important

with increasing renewables/decreasing inertia. Combining EMS/WAMS/Weather etc. sources.

System Operating Limits: Advances in determining accurate, dynamic system operating limits for phase angle

differences and oscillations.

Risk Management: Identifying and resolving malfunctions or control tuning issues.

Cyber security methodologies addressing limitations of the present synchrophasor standards.

7. References

1. CIGRE TB 750 – Dec. 2018

2. Tutorial, “Wide Area Monitoring –

Control Room Applications”,

Aalborg, 2019, June 4th

3. Swissgrid SCADA & WAM System

Copyright © 2018

This tutorial has been prepared based upon

the work of CIGRE and its Working Groups.

If it is used in total or in part, proper

reference and credit should be given to

CIGRE.

Disclaimer notice

“CIGRE gives no warranty or assurance

about the contents of this publication, nor

does it accept any responsibility, as to the

accuracy or exhaustiveness of the

information. All implied warranties and

conditions are excluded to the maximum

extent permitted by law”.

Copyright &

Disclaimer notice