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Distributed Grid Intelligence

Dr. Bruce McMillinMissouri University of Science and

Technology

Wednesday June 1, 2011

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Fundamental Technology:

- System Theory Modeling and Control (SMC)

- Advanced Storage (AS)

Enabling Technology: - Distributed Energy Storage Device (DESD)

- Distributed Grid Intelligence (DGI)

- Reliable and Secure Communications (RSC)

IEM

IFMIEMPHEV/PEV

Intelligent Fault Management

Intelligent Energy Management

Plug-In Hybrid Electric VehiclePlug-In Electric Vehicle

System Demonstration: - Plug-In Hybrid Electric and Plug-In Electric Vehicles (PHEV/PEV)

Relationship to Strategic Plan

• Configuration Management

• State Collection

• Fault Diagnosis

Power Management and Economic

Dispatch

Distributed System Management

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Research Objectives

Objective: Perform the necessary research to develop software tools and platforms suitable for the implementation of intelligent, distributed, robust control functions for the FREEDM System. The control functions will be developed by SMC subthrust and other related subthrusts, and should achieve the functionality of IEM and IFM.The long term research plan for DGI is to create a Distributed Grid Operating System that manages the energy resources of FREEDM. The research develops a resilient (secure, dependable, self-healing) and energy efficient management system for FREEDM

Research RoadmapYear 1-4

Distributed coordination of energy resources, based on algorithmic and economic optimization of resource allocation to and from each SST within the IEM;Implementation of FREEDM first in a hybrid environment with distributed C++ code and PSCAD/RSCAD simulation, followed by distributed implementation of DGI in the green hub using networked computers in each SST interconnected by RSC.Fault tolerance and configuration management of both DGI processes and interface to and from the IFM (at the FID level

Year 5-6Development of information security policies for FREEDM and implementation in a combined RSC/DGI environment, integrating messaging, code, and physical behaviorCorrectness specification and formal verification of critical FREEDM functions and security using model checking techniques

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Grid Intelligence Software Module Broker

Resource Manager, Coordinator/State Maintenance

SST Standard Interface

Plug and Play Device Standard Interface

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DGI: Distributed Operating System for FREEDMScalable and Incremental Peer to Peer Functionality supporting plug-in Software ModulesEach Module has various communications requirements – most can be solved with datagram serviceBroker Maintains System State

Active/Inactive SSTsLoad/Supply State of each SSTActive/Inactive Connections to other SSTsFault Tolerant

Major Year 1-3 Accomplishments

DRERs FIDs FIELD DEVICES

Internet-Scale Field Device Interface – DNP3.0

Security & High Fidelity Data ManagementGreenBusTM

Energy Marketin

g

Distributed Energy

Resource Management

Energy Management System

ISO-RTO

Reporting

Distribution

Management System

SCADAOutage

Mgt System

Resource

Planning

Engineering &

Maintenance

Asset & Facilities Managem

ent

AMR& AMI

DESDs SSTs

Custom or Third Party Applications

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Major Year 1-3 Accomplishments

Power Management Algorithm

Fractional Knapsack from SMC, Year 2 – incremental bidding/migrationBalances the power on FREEDM to meet the net demand/supply through negotiation among peer SST nodes to control individual Power Electronics to add or subtract power to / from a shared power interconnection bus

FeaturesInherently Fault-Tolerant (Omission Faults)Reconfigurable & ScalableComputes/Integrates with DD-LMPDemo

Software Modules

GROUP MANAGER

STATE COLLECTION

POWER MANAGEMENT

DGI @ SST

FAULT DETECTION

CONSENSUS SYSTEM

Peer SST Peer SST

DD-LMP

SST 0

SST 0 L

SST 1 H

:

SST n H

SST1

SST 0 N

SST1 H

:

SST n N

SST n

SST 0 N

SST 1 H

:

SST n H

SST 0

SST 0 N

SST 1 H

:

SST n H

SST1

SST 0 N

SST1 N

:

SST n N

SST n

SST 0 N

SST 1 H

:

SST n H

Major Year 1-3 Accomplishments

Group ManagementManages group membership of SST nodes by determining the neighbors/peersHandles transient network partitions or failure of node(s) (through Reorganization) Elects a leader of the group which has special group information to be used by other modules or a new node that joins the group

FeaturesInherently Fault-TolerantReconfigurable & ScalableManages system state for broker software modulesDemo (with power management)

Software Modules

GROUP MANAGER

STATE COLLECTION

POWER MANAGEMENT

DGI @ SST

FAULT DETECTION

CONSENSUS SYSTEM

Peer SST Peer SST

DD-LMP

Member node

Leader node

New node

Failed node

A new node forms a new group with itself

as leader

Network partition due

to failures leads to election within

subgroups

Election between the leaders of

subgroups to merge into a single group

Major Year 1-3 Accomplishments

State CollectionFundamental Problem in Distributed SystemsCollect a causally consistent state of the SST nodes within a groupChandy-Lamport Algorithm

• Circulates a causal marker

FeaturesCollects the load stateCollects program variables for fault detectionIntegrated for all message traffic within the broker

Software Modules

GROUP MANAGER

STATE COLLECTION

POWER MANAGEMENT

DGI @ SST

FAULT DETECTION

CONSENSUS SYSTEM

Peer SST Peer SST

DD-LMP

SST 0

SST 1

SST 2

SST 3

Inconsistent State

Messages are recorded as received before they

are sent (at SST 3)

Consistent State

Messages events are recorded in causal order

DGI Progress

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Major Year 1-3 Accomplishments

Development of D-LMP (from SMC, Year 3)Experimentation with multiple power management algorithms (consensus from SMC Year 2,3)

Power System Simulation Environment with Distributed Systems Interface to Simulink and PSCAD/RSCAD (Year 3)

Software Modules

GROUP MANAGER

STATE COLLECTION

POWER MANAGEMENT

DGI @ SST

FAULT DETECTION

CONSENSUS SYSTEM

Peer SST Peer SST

DD-LMP CONSENSUS SYSTEM

DD-LMP

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Major Challenges

The primary significant barrier in the development of DGI is bridging the Cyber/Physical/Network boundaries. Power system physics, network stability, and cyber correctness need to be represented on a common semantic basis to

1) create and validate the specification of salient control and resilience features of FREEDM,

2) verify the specification of FREEDM’s resilience against models of the implemented system,

3) provide test and validation of FREEDM’s operation, 4) assess the risks of and threats to FREEDM’s operation.

Response to 2010 SV: Actions Taken

SVT: The DGI and SMC subthrusts must work closely

Technical coordination among SMC, DGI, and Intelligent Energy Management (IEM) and Intelligent Fault Management (IFM)Research within SMC and DGI cultivates multiple optionsSMC, DGI and RSC involve three very different disciplines: power and control engineers, software engineers and communication and network engineers.

• Develops significant cross-disciplinary experience • Possibility to consolidate SMC, DGI and RSC into one cluster and have a

cluster leader with strong domain knowledge to coordinate and lead the activity.

• DGI has emerged as the driving force drawing from SMC and RSC to create the operating system for IEM and IFM.

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Related Posters

Y3.F.C1 Project Report – Distributed Control of FREEDM SystemBroker ArchitectureD-LMP and Consensus

Y3.F.C14 Project ReportInteracting control approach

REU Poster – Group Management SystemInformation Flow/SecurityDemo of DGI Power Management and Reconfiguration

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Year 4 and Beyond

The goal of the next few years is to integrate the DGI operating system with the IEM/IFM in the digital testbed using RSC as a delivery mechanism.

Develop lightweight RSC protocols integrated with DGI algorithms for efficiency, fault tolerance, and securityInterface with the IFM so that faults from the FID cause a reconfiguration of DGI, and faults detected by DGI are communicated to the FID.

Economic models of D-LMP become part of the software module plug-in of the DGI broker architecture as Distributed Distribution LMP (DD-LMP).

As the center moves forward, fault tolerance, correctness and security considerations are cross-cutting throughout DGI and RSC.

Ultimately, DGI will be deployed in the distributed green hub and digital testbed as their operating system.