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Smart Distribution Systems: Communications Perspective

S. S. (Mani) VenkataAlstom Grid and University of Washington (UW)

mani.venkata@alstom.comvenkata@ee.washington.edu

2011 SECON Workshop Panel PresentationSalt Lake City, UT

June 27, 2011Co-author: Sumit Roy, UW

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Simple concept Robust; Effective Not much changed in

the last century

Complex in execution Thousands of

classical, central power plants

Web of transmission lines (above 120-kV)

More complex web of distribution lines

(below 69-kV)

“Edison’s Grid” Today

Generating Plant

End User

Transmission Line

Substation

Distribution System

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Smart Grid: A Digital, Information-Age Grid

Basic structure – Today’s (Edison’s) grid is the starting point– Applies information technology – Much more information and control

Power of Timely information– Deregulation– Infusion of new technologies– More precise system design and operation– Improved reliability, efficiency, safety, security and

cost – Ability to meet customer needs– More products and services– Reduced emissions and environmental impact

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Venkata4

What is in Store for the Future?

The real world is full of uncertainties Many needs of the society are

geographically imbalanced Energy demand and supply unbalance will

continue to exist in the future Global population will increase by 30% to

8 billion in the next 40 years How do we prepare to meet the challenges

and take advantage of the opportunities?

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Venkata5

Global Issues of Concern (contd.)

Ecology and environment protection is essential

– Global warming is one critical example

Next to air and water, energy is the most important need of the society

How to achieve balance between all conflicting forces?

Seeking sustainable energy resources is the answer without sacrificing air and water quality

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Venkata6

Need for Reduced Political Barriers

Governments should aim for reduced bureaucracy

Regulators need to balance societal and utility needs.– Reduced time for approval for new

projects Utilities have to balance their internal

enterprise management in the most efficient and effective ways

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3277 Electric Distribution System Utilities

Distribution Systems is neglected step child Distribution System serves 131 Million

Customers 3.1 Million miles of Distribution lines Electrical infrastructure is ageing rapidly

(?) Total Revenue $256 billion / year Average cost of retail energy sales $0.074 /

kWh Average cost of power generation $0.041 /

kWh Total cost of distribution losses $6.9

Billion / year

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Legacy System Deficiencies

Little flexibility and intelligence Outdated network Unacceptable performance

measures Consumer cost of service issues Environmental issues Limited information from the

electric facilities. The visibility is only provided by

SCADA monitoring and control of the distribution substations with little or no telemetry or control of distribution line devices.

© 2010 Copyright S. S. Venkata

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Venkata9

Why the Smart Grid Revolution?

Running today's digital society through yesterday's grid is like running the Internet

through an old telephone switchboard

Running today's digital society through yesterday's grid is like running the Internet

through an old telephone switchboard

’’’’‘‘‘‘

Reid DetchonReid Detchon

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Venkata10

Impetus for Smart Grid Development

Deregulation (re-regulation?) Development of new

technologies Protection of environment and

ecology Meet customer needs and Birth of “Smart Grid” (Intelligent

Grid)

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Venkata11

Optimal Performance Measures for Smart Grid Development

Customer Satisfaction Efficiency Reliability Voltage and frequency regulation Power Quality Economy Environment and ecology Regulatory Security (system and cyber) Safety

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Smart Grid Components

Generating Plant

End User

Transmission Line

Substation

Distribution System

Broadband over Power lines

—Provide for two-way communications

Monitors and smart relays at substations

Monitors at transformers, circuit breakers and reclosers

Bi-directional meters with two-way communication

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Incorporates entire energy pathway, from generation to customer High-speed, near real-time, two-way communications Sensors, solid-state controllers, switches, protective devices,

transformers, enabling rapid diagnosis and corrections Distributed Energy Resources (DER)

Distributed Generation Energy Storage Demand Response Plug-in Electric Vehicles

An Integrated Energy SystemAn Integrated Energy System

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Demand Management• Better demand control = reduced

generation reserve requirement• Control demand to match supply• Pricing based on real-time market

Renewables Management• Shape load to generation

• Manage intermittency• Maximize renewables

• Supply-based pricing

Asset Management• Improve field efficiency• Real-time asset status & control• Expanded reliability• Extended asset life

Customer-Enabled Management• Automatic control of electronic

devices• Real-time pricing • New services and products• Enable customer choice

Smart Grid BenefitsSmart Grid Benefits

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Smart Grid: Architectural View

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Smart Grid Comm. Standards Domains

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T&D Wide-Area Networks

Many of these are considered obsolete or aging in the general IT world

Still in common use in the power system

Name Notes

Frame Relay Packet-switched, no reliability guarantee

SONET Campus or city backbones

WDM Wavelength Division Multiplexing – follows SONET

Microwave Proprietary, used in geographically difficult areas

Satellite Various proprietary technologies, costly

Trunked Radio Licensed, one broadcast channel, one return

Spread-Spectrum Unlicensed frequencies, more efficient

IP Radio Like trunked radio but with IP addressing

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T&D Substations

Automation common in transmission Business case tough in distribution Well-known problems and solutions Moving to the next level

Name / No. Description Status

IEC 61850 Object models, self-describing, high-speed relaying, process bus

Widespread in Europe, beginning here

DNP3 Distributed Network Protocol Most popular in NA

Modbus Evolved from process automation Close second

COMTRADE Fault Capture file format Widespread

PQDIF Power Quality file format In use

IEC 62351 Security for power systems Recently released

1919

Access Wide-Area Networks

Used to reach the Collector or Substation Too expensive, too unreliable or too slow for actual

access to home

Name Notes

PSTN Public Switched Telephone Network – dial-up, leased lines

DSL Digital Subscriber Line - Telco IP-based home access

Cable DOCSIS standard for coax IP-based home access

WiMAX WiFi with a backbone, cellular-type coverage

Cellular Various technologies e.g. GSM/GPRS or CDMA/EVDO

FTTH Fiber to the Home. Passive Optical Networks (PONs)

PLC Narrowband Power Line Carrier – the “old stuff”

Access BPL Broadband over power line to the home

Paging Various proprietary systems, POCSAG

2020

Field Area Networks – Distribution and AMI

Offerings mostly proprietary– Wireless mesh, licensed or unlicensed– Power line carrier, narrowband or

broadband– New standard activity just started in 2008

Open standards not useful yet– Cellular, WiMAX, ADSL, Cable, FITL– Not economical or not reliable or both– Mostly only reach the Collector level

Interop solution: common upper layer– Network layer preferred: IP suite– Most don’t have bandwidth

Application layer instead: ANSI C12.22– Too flexible, not enough interoperability– Need guidelines, profile from users

More bandwidth the main solution!

Metering NetworkMetering Network

NetworkA

Metering NetworkMetering Network

NetworkB

A B

BA

2121

Home Area Networks

ZigBee and HomePlug alliance– Popular open specifications

LONWorks, Insteon, Z-Wave, X10 – popular proprietary networks

Challenges coming in Electric Vehicles

Name Number Notes

Ethernet IEEE 802.3 Substation LANs, usually fiber optic

WiFi IEEE 802.11 Access by field tool, neighborhood AMI net

ZigBee IEEE 802.15.4 Customer premises automation network

HomePlug 1.0, AV, BPL Powerline comms, in and outside premises

6LowPAN IEEE 802.15.4 The “approved” IPv6 wireless interface

OpenHAN HAN SRS v1.04-2008

Power Industry requirements definition!

22Submission Claudio Lima, Sonoma Innovation

October 2009

The Smart Grid Communications Physical Architecture

Page 6

doc.: IEEE P2030-09-0110-00-0011

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NIST’s System Architecture

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24Submission Claudio Lima, Sonoma Innovation

October 2009

Smart Grid Logical Communications Architecture

Page 7

doc.: IEEE P2030-09-0110-00-0011

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Central GeneratingStation

Step-Up Transformer

DistributionSubstation

ReceivingStation

DistributionSubstation

DistributionSubstation

Commercial

Industrial Commercial

Gas Turbine

RecipEngine

Cogeneration

RecipEngine

Fuel cell

Micro-turbine

Flywheel

Residential

Photovoltaics

Batteries

Residential Data Concentrator

Control Center

Data network Users

Distributed Computing Infrastructure

Power Infrastructure

Power and Computing Infrastructure

Source: EPRI IntelliGridSM Project