architectural models for distributed grid structures and ... · a grid architecture is the highest...
TRANSCRIPT
Architectural Models for Distributed Grid Structures and Grid Virtualization
Jeffrey D. Taft, PNNLPEAC 2020
Seattle 3 March 2020
PNNL-SA-151709
Re-Shaping of the Grid is Inevitable
source: P De Martini9
Purposes:o Identify legacy constraints
o Remove barriers and refine essential limits
o Help manage complexity (and therefore risk)
o Support early stage modernization processes
o Identify gaps in structure, technology
o Assist communication among stakeholders
o Define platforms
o Inform interfaces and interoperability
Architecture An abstract depiction of a system,
consisting of black box components, structure, and externally visible properties
System Architecture & Grid Architecture
Grid Architecture is the application of system architecture, network theory, and control theory to the electric power grid.
A grid architecture is the highest level description of the complete grid, and is a key tool to help understand and define the many complex interactions that exist in present and future grids.
Grid Architecture Methods
• Clarity of definitions• Focus on structure• Uses foundational
principles• Driven by:
• User requirements• Emerging trends• Public policy/regulation
• Agnostic to:• Products and services• Business models• Hype cycles
• Reference architectures are instructive, not prescriptive
Manage ComplexityProduce Insight
Customer expectations
Emerging trends
Policy/Reg
Grid Present State
Systemic Issues
Architecture Principles
Architecture Development
Architecture
Objectives
Grid Architecture Focuses on Structure
Because we have inherited much legacy grid structure, new capabilities and improved characteristics can require understanding of existing grid structure and potential changes to grid structure
• Get the structure right and all the pieces fit into place neatly, all the downstream decisions are simplified, and investments are future-proofed
• Get the structure wrong and integration is costly and inefficient, investments are stranded, and benefits realization is limited
Core ProblemDetermine the appropriate new structures or minimal structural changes to the grid that:
• Relieve crucial constraints on new capabilities
• Limit propagation of undesired change effects
• Strengthen desirable grid characteristics• Simplify design and implementation
decisions
AgileFlexible
ExtensibleObservable
ResilientReliable
AffordableFuture-proofed
etc.
Grid
Coordinated Storage Networks
Variable Structure Grids
Logical Energy Networks
Buffered grids
Modular grids
Virtualized grids
Distributed Coordination
LayeredPlatforms
DSOs and T/D Integration
Grid Visibility/Observability Evaluation/Optimization
Instrumented grids
Grid Architectures& Concepts
provide New Structures
that combineto form Modern Grids
Layered Decomposition&
Laminar Frameworks
Gas/Electric ConvergenceInter-structure Coordination
GMLC Reference Grid Architecture Views
Layering and Platforms
Platform is a Powerful Architectural Concept
• This is about structure: how system elements grouped, organized, and related to each other
• Distinguish common support capabilities (“foundation” or “core”) from uses or applications
8
A platform is a stable collection of components that provide fundamental or commonly-needed capabilities and services to a variable set of uses or applications through well-defined interoperable interfaces.
Some Key Properties of a Platform• Separates foundation functions from end uses (“applications”) via
layering• Provides a set of services and capabilities that are useful to many
applications• The platform is stable over time, while the applications may
change frequently• Provides isolation of changes between applications and
underlying infrastructure• May scale (adjust resources) to support variable demands from
applications• Open: third parties can freely create applications that use the
platform (needs open standard interfaces)
9The value of a platform is spread across many uses.
Layering is a Powerful Architectural Concept
• Partition structure into stacked layers• There may be two or more layers in a platform
• Layer n isolates layer n-1 from layer n+1• Logical/physical layer separation
• Classic example: communication logical/physical layer decomposition
10
n+1n
n-1
General layer decomposition
Communication logical/physical decomposition
11
Layered Structures Limit Change Impacts
Layered architectures are popular in software & network design where they are often called stacks
Layering in software is often associated with abstraction and virtualization (e.g. hypervisors for virtual machine environments)
In all such cases, a principle advantage is that a given layer isolates the layers above and the layers below from changes in each other
Platforms separate stable from transient functions
Vertical decomposition Layer re-association
Disjoint Sensor Sets
System 2
Application 1
Data Exchange via Interop Standards
System 3
Application 2
Application 3
System 1
CommunicationNetworks
Siloed ApplicationSystemsAMI DMS DERMS
Physical Infrastructure
Communication Network
R
DG
DG
Device Operations(Feeder)
Circuit Operations(Substation)
System Operations(Control Center)
Sensor Network
NetworkServices
Microvirtualizer
LegacysensorSmart
sensors
App 2
App 1
App 3
Distribution Platform
Silo-to-Layer Conversion
Sensing and Measurement Architecture for Grid Modernizationhttps://gridarchitecture.pnnl.gov/media/advanced/Sensor%20Networks%20for%20Electric%20Power%20Systems.pdf
Distribution Platform Concept
18
Expanded Cyber-Physical View of Electric Distribution as a Platform
Physical
Distributed Coordination
Definitions• Decentralized System – multiple separate entities
operating independently with at most some small amount of supervision
• Distributed System – decentralized system where the parts cooperate to solve a common problem
• This implies some form of peer-to-peer interaction and communication
• Coordination is the means by which a set of decentralized elements to cooperate to solve a common problem, thus becoming a distributed system This is the essence of distributed system function
• Therefore coordination structure is a key aspect of distributed systems, distributed control, etc.
Definition: The Grid Coordination Problem• Grid coordination is the systematic operational alignment
of utility and non-utility assets to provide electricity delivery
• Coordination was not a well recognized issue for electric distribution until fairly recently Some forms have been around a long time
o C&I DRo Bulk gen in deregulated industry segments
• The motivation for the present level of interest is the rise of two things: Distribution-connected generation and storage Flexibly controllable loads
This is an issue because many of these resources are not owned by the utility and often cannot be controlled directly.
• Want structure to be derived rigorously• Need a distributed form with knowable properties• Here we are not interested in a specific solution but
rather a class of solutions• We wish to extract essential structure by
understanding the problem class
Structural Basis for System Coordination
Mathematical Basis from Optimization Theory
Laminar CoordinationFramework
11
Network Utility Maximization viaLayering for Optimization Decomposition
• Well-known in optimization theory for solving problems with highly coupled constraints
• We will use the math to induce a coordination structure
Essential Laminar Coordination Structure
• Multi-layer structure• “Vertical” chain of
coordination nodes: scalable message flow
• Core repeating building block: coordination domain
• Scalable• Distributed
Coordination Domains & Laminar Networks
18
ISO/RTO/BAA
DSO DSO DSO
PrimaryDistributio
n Substation
PrimaryDistributio
n Substation
PrimaryDistributio
n Substation
PrimaryDistributio
n Substation
Community Solar
RDistribution Scale Storage
Prosumer DERB2G Services
SDirect Inter-DSO Power Flow
UPFC R
Prosumer DERB2G Services
Merchant Storage
Coordinator node
Laminar terminal node
Inter-domain Communication bus
Electrical connection
21
Primary Coordination Domain Structure
22
Coordinator Node
Distributed Intelligence Layering
Compute/StorageCompute/Storage Compute/
Storage
ESOprosumeraccess
IPv6 Stack
ESO NOC
Feeder Control
Local Area Section
Network Control AA SubstationDistribution Control
timingtiming timing
timin
g
timin
g
BuildingEnergy
Controller
Distribution Control CenterISO Control Center
Critical Substation
Primary Distribution Substation
VirtualizationApp Protocol Stack
Coordinator
Analytics
Coordinator
Local Area Grid Control Apps
Coordinator
Feeder/Section Control Apps
Grid Devices and Subsystems
Coord Signals
timing
Substation
PV Inverter
Analytics
Device Apps
VirtualizationApp Protocol Stack
Secondary System orPremises Control
Device
Balance Control Apps
Analytics
Asset Mgmt Apps Asset Mgmt Apps
Coordinator
Zone Control Apps
Analytics
Asset Mgmt Apps
Coordinator
Data Mgmt Tools Data Mgmt Tools
Home EV Charger
Market Apps
Coordinator
Premises Control Apps
App Mgr
Analytics/Vis Tools
SA Gateway Head
Data Mgmt Tools
Analytics/Vis Tools
SA Gateway
Data Mgmt Tools
Analytics/Vis Tools
SA Gateway
Data Mgmt Tools
Analytics/Vis ToolsTools Layer Analytics Tools
Network &Compute Layer
Apps Layer
hypervisor
Grid Data TrafficResidential
Commercial and Industrial
X2ESO Data Traffic
timin
g
timin
g
SP n
etw
ork
Aggregation
VPN
ESO
AnalyticsAnalytics
Sys Control Apps
Asset/Perf Apps
Analytics
Energy Mgmt Apps
ESO Apps
App Container
hypervisor
App Protocol Stack
timin
g
timing
Coordinator
Data Mgmt Tools
Analytics/Vis Tools
Grid Data TrafficVPN
X2ESO
Virtualization VirtualizationApp Protocol Stack
VirtualizationApp Protocol Stack
VirtualizationApp Protocol StackApp Protocol Stack
Compute/StorageCompute/Storage
timin
g
timin
g
SP n
etw
ork
DiscreteGrid
Devices& Systems
LocalEthernet
BAA Level System Zone
Meter
Connectivity Compute/Storage Software
Platform Layer
Distribution Grid Virtualization
Logical Energy Networks
• A LEN is a segment of a primary feeder with associated devices and loads
• Ideally, each LEN has three energy sources available to it: Fed from two primary distribution feeders Some amount of DG/DS resource internal to the LEN that is
utility controlled or coordinated
• This structure recognizes two classes of DER: Edge resources (non-utility owned) Core resources (utility owned/controlled)
LENs enable distribution grid virtualization. Layering with Laminar Coordination enables grid platforming.
LEN 5
LEN 3PFC
LEN 2R
LEN 4
LEN 1
Agg 1 Agg n
Substation A
Substation B
DER DER DER
DER
DER
R
PFC
Recloser
Power Flow Controller
Agg DER Aggregator
DO/DSO
Load
Load
LoadLoad
Load
Load
Load
DG/DS
DG/DS
DG/DS
DER
Utility core resources
Non-utility edge resources
Logical Energy Networks
DSO/Laminar/LEN Virtualization Composite View
DSO/DO
NetworkServices
Microvirtualizer
LegacysensorSmart
sensors
Sensor Network
Smartsensors
NetworkServices
Microvirtualizer
LegacysensorSmart
sensors
Physical Infrastructure
R
DG
DG
Physical Infrastructure
R
DG
DG
Physical Infrastructure
R
DG
DG
Laminar Coordination Node
LEN Perimeter
Logical Energy Network Layer
Sub-LEN Laminar Network Layer(s)
Sensor/Comms Layer
Electric Infrastructure Layer
DistributionPhysical Platform Layers
DistributionVirtual Platform Layers
Coordination Data FlowNote: DER Operators not shown.
Balancing Area
Dispatch/Schedule
Grid Virtualization• Extend the platform idea across the grid: layered decomposition• Virtualize Distribution in a manner analogous to Transmission• Obtain the operational flexibility resilience benefits of microgrid
networks without physical partitioning• Facilitate DER penetration and extraction of operational benefits to
the grid
Distribution System. Incl. Core Resources Transmission SystemsT/D Substations
Laminar Domain
Laminar Domain
Laminar Domain
Laminar Domain
Laminar Domain
Laminar Domain
Logical Energy Network
Logical Energy Network
Phys
ical
Str
uctu
reVi
rtua
l Str
uctu
re
Bulk Power System DomainDistribution Domain
Loads & edge resources
Balancing Area Balancing Area Balancing Area
Phys
ical
Str
uctu
reVi
rtua
l Str
uctu
re
Trans Sys
Logical Energy Network
DSO/DO System Operator
Trans Sys Trans Sys Trans Sys Trans Sys Trans Sys
Gen & storage resources
Coordination Interface
Physical Interface
Jeffrey D. Taft, [email protected]
http://gridarchitecture.pnnl.gov/