Distributed Real-Time SystemsDistributed Real-Time Systemsfor the Intelligent Power Gridfor the Intelligent Power Grid

Prof. Vincenzo LiberatoreProf. Vincenzo Liberatore

Intelligent Power GridIntelligent Power GridSituational awareness by means of time-stamped data collection, real-time wide-area Situational awareness by means of time-stamped data collection, real-time wide-area visualization, and data integrity within and outside an operator’s own area.visualization, and data integrity within and outside an operator’s own area.Improvement of the quality of models and simulations by continuously matching Improvement of the quality of models and simulations by continuously matching models with measured data, for example to formulate and develop improved models with measured data, for example to formulate and develop improved provisioning and contingency plans, and predictive models for security assessment provisioning and contingency plans, and predictive models for security assessment and enhancement. and enhancement. Timely and accurate information dissemination to all key stakeholders, including state Timely and accurate information dissemination to all key stakeholders, including state and local officials, as wells as customer communication that is more scalable than and local officials, as wells as customer communication that is more scalable than one-on-one telephone calls.one-on-one telephone calls.Proactive operations of facilities. Proactive operations of facilities. Real-time actions and distributed control of protection devices to prevent cascading Real-time actions and distributed control of protection devices to prevent cascading failures or for the graceful degradation of user service based on service priorities, etc.failures or for the graceful degradation of user service based on service priorities, etc.Real-time wide-area control to minimize power generation over-provisioning.Real-time wide-area control to minimize power generation over-provisioning.Context-dependent models and control of massive and cascading failures via Context-dependent models and control of massive and cascading failures via predictable component interactions to achieve robustness, fault-tolerance, or graceful predictable component interactions to achieve robustness, fault-tolerance, or graceful performance degradation.performance degradation.Large-scale distributed real-time embedded software development according to the Large-scale distributed real-time embedded software development according to the best practices in Software Engineering. best practices in Software Engineering. Integration of legacy systems as well as the plug-and-play introduction of novel Integration of legacy systems as well as the plug-and-play introduction of novel components and solutions.components and solutions.Support for ubiquitous alternative energy generation systems and the seamless Support for ubiquitous alternative energy generation systems and the seamless integration of these systems into utility operation. integration of these systems into utility operation. Market dynamics, for example, in the context of power routing transactions and Market dynamics, for example, in the context of power routing transactions and regulatory issuesregulatory issues

Distributed Real-Time and PowerDistributed Real-Time and Power

Distributed Real-Time Embedded systems provide Distributed Real-Time Embedded systems provide underpinning of underpinning of

CommunicationCommunication Software DevelopmentSoftware Development

Critical for objectivesCritical for objectives Situational awarenessSituational awareness

Distributed software components monitor phase angles and other Distributed software components monitor phase angles and other quantities of interestquantities of interestReport to visualization centers, logging facilitiesReport to visualization centers, logging facilitiesSupport cooperative workSupport cooperative work

On-line diagnosticsOn-line diagnostics Off-line simulations, forensicsOff-line simulations, forensics

Distributed controlDistributed controlAutomatically close the feedback loopAutomatically close the feedback loop

Short-Term Challenge: Short-Term Challenge: Co-SimulationCo-Simulation

Simulate jointly the computer network and the gridSimulate jointly the computer network and the gridExpertiseExpertise

Computer Networks simulations (Prof. Liberatore)Computer Networks simulations (Prof. Liberatore) Hybrid System simulations (Prof. Branicky)Hybrid System simulations (Prof. Branicky)

Previous workPrevious work Ns2 and differential equation solver [BLP03, etc.]Ns2 and differential equation solver [BLP03, etc.] Oak Ridge National Labs, etc.Oak Ridge National Labs, etc.

Future workFuture work Co-simulation of computer networks and power systemsCo-simulation of computer networks and power systems

Integration with ModelicaIntegration with Modelica Formulation of objectives and scenariosFormulation of objectives and scenarios

Co-Simulation MethodologyCo-Simulation Methodology

Simulation languages

Bandwidthmonitoring

VisualizationNetwork dynamics

Plant output dynamics

Packet queueing and forwarding

Co-simulation of systems and networks

Plant agent(actuator, sensor, …)

Router

Controlleragent(SBC, PLC, …)

[Branicky, Liberatore, Phillips: ACC’03]

Medium-Term Challenges (I)Medium-Term Challenges (I)

Real-Time Networked Real-Time Networked Control (I)Control (I)

Close-feedback loop in real-Close-feedback loop in real-time over a networktime over a network

Network Quality-of-Service Network Quality-of-Service (QoS)(QoS)

Prevent timing failuresPrevent timing failuresE.g., fully-distributed QoS E.g., fully-distributed QoS [L04a][L04a]

Allocation of network resources Allocation of network resources [ABLP06][ABLP06]

Depends on system Depends on system requirements (stability, requirements (stability, performance)performance)Fully distributed, Fully distributed, asynchronous, scalableasynchronous, scalableDynamic and flexibleDynamic and flexibleOptimization approachOptimization approach

Medium-Term Challenges (II)Medium-Term Challenges (II)

Real-Time Networked Control (II)Real-Time Networked Control (II) Application adaptabilityApplication adaptability

End-point adapts to timing failures [L06]End-point adapts to timing failures [L06] In-network synchronization (IEEE PTP) [B06]In-network synchronization (IEEE PTP) [B06] Real-Time Secure ManagementReal-Time Secure Management

Play-BackPlay-BackSequence number

time

Packet generation

Play-back

Packet arrival

Medium-Term Challenges (III)Medium-Term Challenges (III)

Software EngineeringSoftware Engineering Large-scale distributed Large-scale distributed

real-time embedded real-time embedded systemssystems

Functional scalability [L04]Functional scalability [L04] Software development Software development

platforms and middlewareplatforms and middlewareE.g., RT Corba and power E.g., RT Corba and power applicationsapplicationsMulti-agent software Multi-agent software systems [ACKRNL03]systems [ACKRNL03]

Integration of software, Integration of software, protocols, and standardsprotocols, and standards

ConclusionsConclusions

Intelligent GridIntelligent Grid

Distributed Real-Time Embedded SystemsDistributed Real-Time Embedded Systems

Immediate needImmediate need Co-simulationCo-simulation

Long-term needsLong-term needs Software EngineeringSoftware Engineering Networked ControlNetworked Control