The Future of Power SystemProtection, Control &

Monitoring

Mark AdamiakGE Digital Energy April 7th 2009

Power System Challenges

The worlds population is estimated at 6.76 B people

Electricity Demand….2x by 2030

emerging markets exploding

Electricity demand … 2X by 2030Billions of kW hours

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

1980 1985 1990 2003 2010 2015 2020 2025 2030

AsiaAfricaMiddle EastEurope & EurAsiaCentral and S AmericaNorth America

Sources: EIA-DOE International Energy Annual 2004 & International Energy Outlook 2006

Energy consumption growing

Electricity Demand….3x by 2040

source: U.S. Army Corps of Engineers EERDC/CERL TR-05-21

Today’s Power System ChallengesDemand for electricity is growingAt an anticipated growth in demand of 2% per year, this works out to a 50% increase in demand over the next 20 years

Environmental Effect50% increase in the amount of generating capacity required is also a 50% increase in environmental costs

Aging infrastructure60% to 70% of the transformers, transmission lines, and circuit breakers nearing the end of their usable life

Safety Concerns 32,807 people were injured in ARC Flash incidents the U.S between the years of 1992 and 1998. The average economic impact to companies on each incident is between $8M-$10M in direct and indirect costs.

Economic ImpactPower outage in the U.S has cost over $150B annually in productivity and lost business

Renewable and Distributed Energy

Global Wind & Solar PV annual installations

Solar PV

Wind

• US Wind & Solar generation has tripled every year since ’02• This still only accounts for a combined 34GW• Trend expected to accelerate• 12 Million new DER devices expected over next 20 years

source: REN21 2007 update + EER

Transmission Loading Relief vs. Gen

Protection, Control, and Monitoring Technologies . . .

Generation Transmission Distribution Industrial Commercial Residential

Generator Protection & Control

Distributed Generation Management

Microgrid Control

High Voltage Line Protection , Control, & Monitoring Reliability Optimization

Transformer & Feeder Protection & Control

Power Distribution Safety

Distribution Automation

Feeder, Transformer & Motor Protection

Energy Management Systems

Plant Load Shedding & Peak Demand Mgmt

Emergency Backup Power

Sub Metering and Cost Allocation

Wireless CommsEnabling AMI, Demand Side Management & Direct Load Control

Fault Diagnostics & Analytics

Digitizing Primary Equipment

Asset Monitoring

Examples:

Protection and Control Spans the Electron Enterprise

Protection, Monitoring, and ControlChallenges to Address (today):• Grid stability issues• Extensive influx of Distributed Resources

– Protection in a limited current environment– DR/MicroGrid Management

• Optimal Dispatch• Tie Line Control• Load/Generation Shed

• Monitoring/Replacement of the aging P&C infrastructure

The Need for Wide-Area Measurements

• Following the east coast blackout, a federal commission was appointed

• Fault found with utility companies: no real-time knowledge of the state of the power system was available

• Recommendation made: establish a real-time measurement system and develop computer based operational and management tools

This Was after the 1965 blackout!This Was after the 1965 blackout!

Cleveland Separation – Aug 14, 2003

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

0

15:05:00 15:32:00 15:44:00 15:51:00 16:05:00 16:06:01 16:09:05 16:10:38Time (EDT)

Rel

ativ

e Ph

ase

Ang

le

Cleveland West MI

Normal Angle ~ -25º

Reference: Browns Ferry

Phasors > Rotating rotors = alternate currents / voltages

A

VA

A

B

B C

C

VBVC

N

S

> Phasors are well established means of representing ac circuits

=

Synchrophasors

UTC Time

Charles Proteus Steinmetz (1865-1923)Complex Quantities and their use in Electrical Engineering; Charles Proteus Steinmetz; Proceedings of the International Electrical Congress, Chicago, IL; AIEE Proceedings, 1893; pp.33-74.

SynchrophasorsStrobe Light Analogy

0o

30o

60o

90o

120 o

150 o

-30 o

-60 o

-90o

-120o

-150

o

180o

N

S

Strobe Light Analogy

0o

30o

60o

90o

120 o

150 o

-30 o

-60 o

-90o

-120o

-150

o

180o

IEEE C37.118 Synchrophasor Definition

X1

UTC Time Reference 1

Cosine Reference

+θ*

UTC Time Reference 2

- θ*

X2

*Corrected for anyfilter delay

θ±∠=2nXPhasor

Off-Nominal Frequency Response of the Fourier Transform

Mathematical FoundationPhasor Model and Taylor Series Expansion of Model

))((Re2))((Re2)( 22 tfjtfj etXXaletXaltx •••• ••+•≈•≈ ππ &

Traditional “Boxcar” Phasor Calculation

Nnj

N

Nn

enxN

Yπ2)2/1(

12

2

)(2 +−−

−=

•= ∑

Compensated Synchronized Phasor1

1 Patented

)2sin(2

)( 1

NN

YYjYX MMMM π

•

−•−≈ −

PMU ImplementationPMU = Phasor Measurement Unit

δ1 δ2

δ3

δ4

δ5

SynchronizedPhasors

GPSClockPMU

System Integrity Protection SchemesPDC = Phasor Data Concentrator

Monitoring / EMS > 1 sec

PMU PMU PMU. . .

Local Operation

Very High-speedDecisions

10-100 ms time frame

High-speedDecisions

100 ms – 1S time frame

PDC PDC

National Operation

PDC

. . . . . .PMU PMU PMU PMU PMU PMU

Mux

Station 1 Station 2 Station n

Configuration/File-

Archive/SOE

• Status• Settings• Triggered files• SOEOC48

2GB/sec

• Streaming Synchrophasors

Synchrophasor System Physical Architecture using SONET

Data

Archive

User

Interface/Apps

PMU

Architecture of the C–RAS Scheme

Telecomm/Protection Technologies

• Use of IEC 61850 “Goose” • Use of Synchrophasor devices• Use of Central Controller

C-RAS Test Results

080403 Lugo Line Out

0.000000

0.002000

0.004000

0.006000

0.008000

0.010000

0.012000

pressbutton 1

line openconfirmed

pressbutton 2

line openconfirmed

trip

Total Event Time (sec)Network Time (sec)

Device Process Time (sec)

Less Than 12 ms Round Trip Execution Time

Wide Area Measurement Architecture

Data Rate:12 - 60

Measurements per Second

. . . . .

Data CollectionPer Standard over RS485, C37.94,

or Ethernet

Historian

Data Rate:Every 2 SecondsSame Time Stamp

EMS

High Speed ApplicationsOPC / SQL

Comms:SONETEthernet

I. Visualization Applications

II. Analysis & Control Applications

Wide Area System View

+30

PhaseAngle

+20

+10

+00

-10

-20

-30

Phasor Viewing

0

559.26

030

60

90

120

150180

210

240

270

300

330Grand Coulee

John Day

Malin N

Colstrip

Big Eddy 500

Keeler 500 kV

Vincent

Devers 500 kV

Vincent 500kV

Mohave 500kV

Devers 500kV

Grand Coulee 500kV

Angle Reference is Grand Coulee

08/04/00 Event at 12:55 Pacific Time (08/04/00 at 19:55 GMT )

Big Creek System Oscillations of September 13, 2000

Voltage plots for 230 busses

200.0

209.6

219.2

228.8

238.4

248.0

14:44:25.00 14:45:25.00 14:46:25.00 14:47:25.00 14:48:25.00 14:49:25.00 14:50:25.00

Pacific Time

Vincent 230kV

Devers 230kV

Big Creek 230kV

Alamitos 230kV

SO-SCE 230kV

SO-SDGE 230kV

Kramer 230kV

Antelope 220kV

09/13/00 Event at 14:44 Pacific Time (09/13/00 at 21:44 GMT )

Cap-bankCut-in

Line trip

Trip & close

System Frequency View• Frequency – critical parameter for understanding system behavior• FNET project at VaTech tracks frequency after an event• Speed of Frequency Wave:

• 350 Mi/Sec – East• 1100 Mi/Sec – WECC

• MW Lost ≈ ∆f * 31464

I. Visualization Applications

II. Analysis & Control Applications

PMU Indirect

Synchrophasor-Based StateMeasurement • Linear estimator

• True “simultaneous” measurements• Complete observabilityrequires PMUs at 1/3 buses• Incomplete observability possible• Dynamic update possible• Foundation for “closed loop” control

State estimation with phasor measurements:E1E2E4I1I2I3I4I5I6

=

E1E2E3E4

1 0 0 00 1 0 00 0 0 1

y1+y10 -y1 0 0-y1 y1+y10 0 00 y3+y30 0 -y30 y2+y20 -y2 00 -y3 0 y3+y300 0 -y4 y4+y40

12 3

4

0

I1 I2I3

I4

I5

I6y1

y2

y3

y4which correspondsto the measurementson the network.

Synchrophasor BasedBackup Current Differential

PMU

PMU• Hi-Speed data streaming standardized (30-60 phasors/sec)•Low Communication latency available (7ms as seen previously)• Precise Zone isolation through current differential protection• Positive Sequence Current based• Bonus: Double ended fault location

Zone ofProtection

Addresses NERC Z3 Issue

PDC/ Controller

Line Parameter Calculation / Dynamic Line Loading

I1 I2L R

1 2

V1 V2

Measure: V1, I1, V2, I2,TambientCompute: R, L, C, Tc

Simple Calculation…High Impact

Adaptive out-of-step relaying

pmupmu

δ t

obse

rve

predictP

δ

Synchrophasor Spectral Analysis

FourierTransform

Input: Synchrophasors Output: Sub-synchronousModal Analysis

A View into the Pole and Zeros of the Power System

Wide Area Monitoring and Control

Transmission Paths500kV Lines

Kemano

Colstrip

Malin

John Day

NavajoHoover

PG&ESCE

SDG&ELADWP

345kV Lines230kV LinesDC Lines

Table Mtn.

Diablo Canyon

Moss Landing

Peace River

Midpoint

San JuanFour CornersCholla

Jim Bridger

IPP

Grand Coulee

McNary

Palo Verde

Mohave

Wide Area Control•1-60 Phasors/sec•Control Range•Control Device Status

PhasorMeasurementUnits

Input Data:•Operate Point change•Linear Control •On/Off

C ON

TR

OL

Data Synchronization &Control Coordination

EMS applicationsfor self-healing grid

StateMeasurement

Microgrid Controllers optimizes site generation

• Selects the most cost effective generation available to support the load

• Optimizes green power by dispatching power storage when excess generation is available

• Indicates amount of energy in storage (Fuel Cell and Diesel)

DER & Microgrid Control

1.2MW Battery on the AEP System

Challenge: Protection in an inverter-based environment

Protection of Inverter-based SourcesOptions:• Require inverter current outputs capable of 3x load

– Adds expense to the inverter• Migrate to voltage-based protection

– Issue on selectivity• Migrate to directional Overcurrent protection

– Requires a communication channel• Incorporation of a MicroGrid Protection Coordinator

Adaptive Protection Provides the Most Flexibility

GE 1.5 MW Reactive Capability

WindFREE™ option allows partial reactive capability when wind is below cut-in

Grid Voltage Regulation via Wind Control

SCR ~3.5

45 mi~10 mi

Collector Bus

Individual WTG

Compensation including charging is required

Pow

er (k

W)

Volta

ge (l

ine-

to-li

ne V

)Po

wer

(kW

)Vo

ltage

(lin

e-to

-line

V)

Voltage at POI

Wind Plant Power Output(20% Variation)

Wind Plant VoltageWind Speed

Wind Speed

Pst < 0.02

UtilityTransmission

Bus (POI)

Actual measurements from a GE 162MW wind power plant.

Control system coordinates wind turbine reactive output to regulate remote grid voltage

3-Phase, 200ms, Zero Voltage Fault

Power recovers to pre-disturbance level in <200ms

Medium voltage bus drops to 0.0

Voltage Level

Active Power (delivered to Medium Voltage bus)From WINDTEST report WT5491/06Bexten Wind PlantThree and Two Phase faults of various depths and durations

Wind Inertia> Controllable variable speed allows “borrowing” of

energy stored drive train inertia> Programmed to appear to the grid as a “virtual

inertia” of H = 3.5– Power pulse of 5% - 10% of rated for up to 10 seconds– Will only respond to large (-0.5 Hz) downward

frequency excursions

58.00

58.50

59.00

59.50

60.00

58.0 a fbul 90 Load 220.0 1 1 60.058.0 b fbul 90 Load 220.0 1 1 60.058.0 c fbul 90 Load 220.0 1 1 60.058.0 d fbul 90 Load 220.0 1 1 60.0

Time( sec )0.0 30.0

No wind

With WindINERTIA

Wind without inertia

Load shed at 58.5 Hz

Time (s)

Technical ApproachSupervisory Controls• Used to optimize electrical

and thermal performance and cost

• Manage feeder connection to bulk grid

• Manage renewable intermittency

Local Controls• Control response based on local measurements.• Robust response to system disturbances and supervisory level commands. • Provide inherent stability and load sharing for grid independent and grid

interactive connections.

measurements

DG

MicrogridNetwork & LoadsGrid

LocalControl

DG

LocalControl

DG

LocalControl

Supervisory Control

SetPoints

SetPoints

User Settings

measurements

DG

MicrogridNetwork & LoadsGrid

LocalControl

DG

LocalControl

DG

LocalControl

Supervisory Control

SetPoints

SetPoints

User Settings

Industrial Load SheddingLoad Shedding solutions to keeps critical processes running

• Identifies when there is a lack of power to supply required load

• Dynamically sheds least critical loads to keep processes essential to the business running

Load Shed Model

IndustrialPower

Complex

G1

G1 Gn

G2Gn

S1

Source 1

S2

Source 2

Sn

Source n

L1

L2

L3

Ln

G2

SnGsGnGG PPPPPPLoad +++++++= ...... 2121

GnGG PPPGeneration +++= ...21

)Re()( serveSpinningGenerationLoadshedGenerationLoad +−=

Microgrid Control System Features3. Tie Line Control – Distributed Energy Resource Aggregation• Energy aggregation: To the grid, the aggregated distribution system looks like one

well-behaved dispatchable energy resource

• Active and reactive power

• Power ramp rate limits

• Ancillary services (voltage/VAR regulation, frequency droop…)

Example: Windfarm tieline Control

GE Company Proprietary75km

SCR ~3.5 (weak interconnection)~20 km

POI 75 KM away! Compensation for long cable runs including charging is required

Collector Bus UtilityTransmission

Bus (POI)

Collector Bus UtilityTransmission

Bus (POI)

Individual WTG

Voltage at POI

Wind farm power output

Optimal Dispatch via Model Predictive Control

Forecasts

Inputs OutputsOptimization800Xm

Model

∑ ∑∑∑= ===

⋅⋅+⋅⋅+⋅⋅=

N

n

K

knknknk

J

jnjnjnj

I

ininini csisiPsicsosoPsocddPdCost

1 111

ηηη

Where: Pd is power out of a dispatchable generatorPso is power out of a storage elementPsi is power into a storage elementηd, ηso, and ηsi are efficiencies for each of the abovecd, cso, and csi are costs for each of the above

Technology Advancements

Aging infrastructure reduces reliability• The average transformers is 40 years old• Transformer failure means a less reliable, less stable grid

Major opportunity for Asset Monitoring

source: William Bartley P.E. Hartford Steam Boiler Inspection & Insurance

Temperature/Gas Monitoring viaBragg Grating

Input Power

Reflected Power PR

PI Transmitted Power

Reflected Wavelength is a Function of Temperature and/or Gas Type

Stated Goal of 61850 Process Bus:Interface with Optical CTs/PTs

Reality: Copper Dominates the Landscape

Design objectives & constraints> Maximum pre-connectorization> Early and comprehensive acquisition

of signals> Fiber-based signaling> Ruggedness and security

paramount> Risk mitigation with built-in

redundancy

What is an Architecture?

•The components of a system• and the rules for putting them together

IEC61850 Alternative Architecture 4: Zone-based CommunicationLine protection zone

Transformerprotection zone

Lineprotection zone

Zoneoverlap

Zoneoverlap

•Observation: 90% of all Zones only require 4 input locations

Optimized System ArchitectureRemote I/O devices (process bus Merging Units - MU) installed in the switchyard to provide complete I/O capability for the system Redundant I/O for critical signalsData acquisition and outputs only, no processing (future-proof)

OptimizedSystem Architecture

Connected via multi-fiber cables (star topology)Fiber cables in trenches, directly buried when requiredPowered via copper wires integrated in the fiber cablePre-connectorized cables

SwitchyardControlhouse

Outdoormulti-fiber cables

System ArchitectureAll switchgear (CBs+CTs, PTs, free-standing CTs, disconnect and ground switches, sensors) interfaced via remote I/O units

SwitchyardControlhouse

Outdoormulti-fiber cables

I/O interface, no processing

System ArchitectureCables terminate on patch panelsUniform switchgear-to-control house layout, no variability

Fiberpatch

panels

SwitchyardControlhouse

Outdoormulti-fiber cables

System ArchitectureUniform IEDs-to-patch panel layout, no variabilityIndoor cables pre-connectorized

SwitchyardControlhouse

Outdoormulti-fiber cables

Fiberpatch

panels

Indoormulti-fiber cables

IED, all I/Osvia fiber

The only tools youwill ever need

Making the Connection

Patch Panel

IED-1Po

rt-1

Port

-2Po

rt-3

Port

-4

IED-2

Port

-1Po

rt-2

Port

-3Po

rt-4

Brick-2

Core

-1Co

re-2

Core

-3Co

re-4

Brick-1

Core

-1Co

re-2

Core

-3Co

re-4

IEC 61850 Guidelines onData Sampling Synchronization:

•The synchronization of this sampling may be done internal or over the network.1

•1 - IEC 61850 7-2 2004

Synchronization

Remote I/O

Synchronization

Remote I/O

Synchronization

Remote I/O

Blue

Synchronization

Devices stay independent –- no need for a master clock

Remote I/O

Blue

Orange

Synchronization

•Sampling Variance: ±1µsec

Nanotechnology in the Power System

New Breakthroughs in Technology

• Nano-Materials: Carbon Nanotubes and new composites

– Lighter/more efficient Windmill and Turbine Blades

• Nano-Detection: Nano Nose, detect as little as 1ppm of gas

– Better detection of transformer gas in oil

• Nano-Coatings: Super-hydrophobic materials

Manipulating structure at the molecular level

Creating new materials

Accelerate new… wind• 2.5-megawatt turbine with

55 meter advanced blades

• Advanced composite hybrid of carbon and fiberglass

• Aeroelastic tailored

• Creates higher efficiency and produces lower noise

Truck

1.5-MW Turbine40-Meter Blade

NanoCoating Technology

Protection from the ElementsSuper-Hydrophobic coatings so repellant that: • Honey slides off it like mercury• Water bounces and beads off

The Energy Sector Application• New transmission & distribution line

coating resists ice build-up

• New coatings protect coastal assets from salt damage

• New transformer winding material fights insulation breakdown

Increased Solar Energy Penetration Low-cost silicon solution using next-gen nano materials

• Cost coming down

• Inverter interface into the Grid

• Self-limiting on fault current

• Intermittent – difficult to dispatch

SummaryThe path is unfolding now, technology can help address:

• Increasing electrical demand

• Green power being more economical, viable and reliable

• Introduces new challenges and opportunities in the P&C world

Heavy lifting . . .• Unprecedented levels of co-operation among the stakeholders• Continued evaluation of new technology for additional benefits• Vision to make the system predictive, self-healing and secure • Continued investments from all stakeholders