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The Grid of The Future: From Vertical to Flat

Decentralized Control:

Benefits, Technologies and Challenges

Santiago Grijalva Georgia Institute of Technology

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Smart Grid functionality restores the

balance

Hydro power

plants

Nuclear Power

Plants Natural Gas

Generators

Transmission

System

Distribution

Substations Customers

Distributed

storage

Solar Farms

Wind Farms

The Emerging Grid

Home Energy

Storage Energy

Efficiency

PHEV

Rooftop

Solar

Distributed

wind

Commercial

Customers

2 © 2014 Georgia Institute of Technology

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Unprecedented Changes

Domain Change Future System

Objectives • Reliability+, Economy+, and Sustainability Sustainable

Sources • Fossil fuel to renewable

• Bulk centralized to massively distributed

• Highly Variable

Renewable

Distributed, Two way

Stochastic

ICCT • Can control entire system through SW

• Interdependency of physical and cyber

• Privacy and cyber-security issues

Cyber-Controlled

Cyber-Physical

Secure, Private

Actors • Consumers can also produce and store

• Consumers seek their own objectives

• Massive number of actors and devices

Prosumers

Smart

Massive

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• How should these systems be controlled and operated?

• Need new control architecture -> Decentralized

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Concept 1: Prosumer Abstraction

• A generic model that captures basic functions (produce, consume,

store) can be applied to power systems at any scale.

• The fundamental task is power balancing:

• Energy services can be virtualized.

External

Supply Energy

Storage

Local

Energy

Wires

Load 1 Load 2 . . . . Load n

INT G D Loss STO STOP P P P P P

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Concept 2: Flat Electricity Industry

Interconnection

ISO

Utility

Grid, Building, Home

S. Grijalva, "Multi-Scale, Multi-Dimensional Computational Algorithms for Next Generation Electric Power Grid", DOE Workshop on

Computational Needs for Next Generation Electric Power Grid, Cornell University, Ithaca, NY, April 18-20, 2011.

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• Interactions occur among entities of the same type (prosumers)

• Can achieve “flatness”

© 2014 Georgia Institute of Technology

S. Grijalva, M. Costley, "Prosumer-Based Smart Grid Architecture Enables a Flat, Sustainable Electricity Industry", IEEE PES

Conference on Innovative Smart Grid Technologies (ISGT), Anaheim, California, January 17-19, 2011.

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Concept 3: Prosumer Services

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• Prosumer exposes

standardized services – Energy balancing

– Frequency regulation

– Reserve

– Sensing and Information

– Forecasting

– Security

– Self-identification

– Voltage control

– Black Start

– Etc.

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Concept 4: Layered Energy Cyber-Physical System

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Device Layer

Local Control Layer

Cyber-Layer

System Control Layer

Market Layer

PV Cells Storage Devices

Building Loads

Gas Storage

Diesel Gen Hydrogen Fuel Cell

Micro PMU

Smart Meters Actuators Sensors

Protections Controllers

Wireless System

SCADA Campus LAN HPC

Firewall Database

Islanding

Balancing SA Forecasting

Decentralized Controller

Virtual Power Plant

Pricing Module

Optimization

EMS

Device Layer

Local Control Layer

Cyber-Layer

System Control Layer

Market Layer

Appliances

Air Conditioner

Water Heater

Pumps

Electric Vehicle Lighting

Flow Sensors

Actuators Temperature

Micro PMU Occupancy Sensors

Security

SCADA Database PC

Firewall LAN

Monitoring

System Level Control Alarm System

Scheduling

BEMS Demand Response

Optimization Module

Forecasting

UPS

Rooftop PV Battery

Microgrid Building

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Decentralized Control

• 20 Self-Optimizing Regions in a Large-Scale RTO System.

• Tie-Line Bus LMP convergence using Decentralized Optimization.

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M. Costley, S. Grijalva, “Efficient Distributed OPF for De-

centralized Power System Operations and Electricity Markets”,

IEEE PES Conference on Innovative Smart Grid Technologies,

Washington D.C., January 17-19, 2012.

© 2014 Georgia Institute of Technology

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Potential Benefits

• Scalable to large number of control points.

• Reduces need for massive communication

• Leverages sensing investment

• Enables solving otherwise intractable optimization problems

• Enables integration of distributed renewables

• Eliminates single point of failure

• Leverages distributed intelligence

• Empowers customers

• Increases information privacy

• Enhances cyber-security

• Incrementally deployable

• Backward compatible

10 © 2014 Georgia Institute of Technology

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Technology Needs and Challenges

Technologies Challenges

Modeling and Simulation

• Prosumer models

• Multi-scale models

• Co-Simulation

• ICCT and physical

• System control and market

• System planning

Device function to prosumer service

What temporal scales

Supporting theory

Market/business models

Information footprint, computation

Control and Operation

• Control theory

• E-CPS theory

Decentralized resilient control of large, open,

uncertain networked network systems.

Layered control theory

Architecture Control Architecture drives

ICC Architecture,

Security Architecture

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Summary

• Future electricity systems will consist of billions of smart

devices and millions of interconnected decision makers.

• A decentralized control and management architecture may

be able to support the objectives and requirements of the

future electricity industry.

THANKS!

© 2014 Georgia Institute of Technology