Requirements for Future Power System Architectures Vom Use Case zum System Hilfen aus der Normung

Transcription

1 Requirements for Future Power System Architectures Vom Use Case zum System Hilfen aus der Normung Dr.-Ing. Mathias Uslar, Prof. Dr.-Ing. Sebastian Lehnhoff Excerpt from module Energy Information Systems (area of specialisation in the masters programme, department of computing science, University of Oldenburg)

2 2 Future Energy Systems We know what we want! Smart Grid Use Cases Balancing distributed demand and generation Curtailing surplus (renewable) generation Shifting timely flexible duty cycles of home appliances Market-based scheduling and dispatch Dynamical reconfiguration of protection and control systems Obviously we need more ICT, but: Is the performance of the ICT- and automation system sufficient? Will the system be safe/secure? Are all the relevant systems connected and able to communicate with each other? Are certain measurements sufficiently accurate/precise? What s the most efficient way to implement this and how much does it cost?! How do we know what to do?

3 3 What do we need? Use Cases (Business Cases) Who will use the system (actors, components)? What for? What are the non-functional requirements? A Reference Architecture Identify interacting (electrical and ICT) systems Focus on ICT-to-ICT/ICT-to-el.system interfaces ICT-Standards Data Models Information Models Mechanisms for Security/Reliability IEC PAS (IntelliGrid Method for Developing Requirements for Energy Systems) Smart Grid Architecture Model (SGAM) IEC TC 57 Seamless Integration Architecture (SIA) Smart Grid Information Security (SGIS) Toolbox

4 4 Use Cases A Use Case is a description of the interactions between users/actors and the system that is to be developed targeting a specific goal Use Cases describe the steps necessary for reaching that goal Abstraction from concrete implementation Description from an external perspective Use Cases describe a service provided to an environment (users, external systems) Specification/requirements analysis and system design Structural viewpoint (a picture is worth a thousand words) Behavior towards external inputs Structural dependencies between actors and components Detailed viewpoint Description of the interactions between actors and components Sequence-, state- and activity-diagrams

5 5 Use Cases (cont d) IEC PAS (IntelliGrid Method for Developing Requirements for Energy Systems) Developed by EPRI in the IntelliGrid Project Suggests a process for developing requirements for new applications in power systems (e.g. Smart Grids) Describes the whole process, starting from exec. business cases to technical engineering Capture Requirements Textual description Activities Interactions Source: IEC PAS 62559

6 6 Use Cases (cont d) IEC PAS Most important: Proposes the usage of formal use cases to help domain experts describing requirements There is a model and a process! 1. Identification of stakeholders/actors 2. Specification of a sequence of actions/steps between actors and components Assumptions the UC is based on Contracts/preconditions Triggering events 3. Identifying non-functional requirements Configuration Quality of Service (QoS) (e.g. availability, latency) Security requirements Data management issues (e.g.: precision, volumes) Constraints/other issues

7 7 Use Case Repositories DKE Repository (based on the model) Read-only-access (LookatMe:LookatMe)

8 8 From Use Cases to Reference Architectures Great: we now have a formalized use case with Abstract actors/components (technically not yet specified), Sequence of actions/steps between actors and components, Non-functional requirements! But: Who/what are my technical actors/components? Who is capable of communicating with whom (with what quality)? Who is allowed to talk to whom? We need a domain-specific reference architecture! Standardized actors/components (repositories) Well-defined relationships between each other Goal: coherent set of formalized use cases! automatically processable! Source:

9 9 A Reference Architecture Smart Grid Architecture Model (SGAM) [...] description of a system s structure in terms of interactions between its element types and their environment. (ISO/IEC 42010) A reference architecture defines restrictions for an instantiation of a concrete architecture Specifies the syntax as well as the semantics for describing a (technical) system What else do we need to address to enable interactions and transactions in Smart Grids? Source: M/490 Reference Architecture WG, CEN-CENELEC-ETSI, 2011 Market Generation Transmission Domains Customer Premise (Home, Building, Industry, EV, Mobility) Zones

10 GridWise Architecture Council (GWAC) Stack 10 A Reference Architecture (cont d) Smart Grid Architecture Model (SGAM) Source: M/490 Reference Architecture WG, CEN-CENELEC-ETSI, 2011 Business Objectives Polit. / Regulat.. Framework Business Layer What business processes and regul. constraints apply? Function Layer Information Layer Which functions are required? Outline of Usecase Subfunctions What Information Data is going Model to be exchanged? Data Model Communication Layer Component Layer Protocol Market Protocol How is the information being exchanged? Generation Transmission Domains What Hardware is required? Customer Premise Zones

11 What (management) functions are allocated where? shown in order to keep the figure readable. Generation Management system Substation automation system WAMS EMS SCADA system FACTS Substation automation system Feeder automation system Dist. Power Quality control system DMS SCADA & GIS system FACTS system EMS and VPP system AMI system Metering-related Back Office system Aggregated prosumers management system Market Source: CEN-CENELEC-ETSI Smart Grid Coordination Group First Set of Standards, 2012 Market place system Trading system Asset & Maintenance management system Weather Forecast & Observation system Generation Transmission Figure 4 - Mapping of Smart Grids systems to the SGAM model Customer premises

12 Which (ICT) components are allocated where? Market Commercial/Home automation subsystem AMI subsystem E-mobility charging infrastructure subsystem Industrial subsystem Laptop Mobile device Meter data concentrator automation device subsystem Generic substation subsystem Automation Bus Substation Integration Bus Appliances Smart Plug Power plant subsystem Source: CEN-CENELEC-ETSI Smart Grid Coordination Group First Set of Standards, Component plane Wholesale Energy Market subsystem Registration Settlement Energy Market Mmgt. EMS SCADA Bb Communication infrastructure subsystem Integration Bus Energy Trading App subsystem Retail Energy Market subsystem (incl. VPP) Energy Trading App. Billing Power Scheduling ERP Asset Management GIS CIS Customer Portal Balance Scheduling CIS Customer Portal MDMS Backbone Network (Bb) Integration Bus Bb Bb Integration Bus Secondary Gen. Ctrl. WAMS EMS Model exchange platform Electric system operation subsystem SCADA OMS DMS DRMS DRMS AMI Head End Condition Monitoring Bb High Speed Bus Communication Front End AMI Head End force subsystem Bb Radio Distributed Energy subsystem Building Management System Customer Energy Management Bb Building Management System Bb Backhaul Network () Balance Of Plant RTU Voltage Regulator Primary Gen. Ctrl. Prot. Relay Oper. Meter Power Generator electronics Phasor Data Concentrator PMU HVDC RTU HV/DC control FACTS control Bay Controller Dig. Sensor Grid Meter FACTS Capacitor NIC controller Voltage Regulator Cap. Bank Controler Prot. Relay AN Fault detector Switch/Breaker Reactor Transformer RTU Prot. Relay Dig. Sensor Grid Meter Capacitor An NIC Feeder control Voltage Regulator Cap. Bank Controler Fault detector Recloser Switch/Breaker Reactor Transformer automation System Customer Energy Management Generation Transmission Consumption An NIC controller Energy Storage RTU Control Rev. Meter Control Load Control Charging PEV Rev. Meter Local Stora Oper. Meter Load AN Charging station PEV NIC Rev. Meter AN NIC Rev. Meter Control HAN Gateway HAN Charging Control PEV Local Storage Oper. Meter Load Access Network (AN) Home Autom. Network (HAN)

13 13 A Reference Architecture (cont d) Smart Grid Architecture Model (SGAM) Source: M/490 Reference Architecture WG, CEN-CENELEC-ETSI, 2011 Business Objectives Polit. / Regulat.. Framework Business Layer Function Layer Information Layer Outline of Usecase Subfunctions Data Model Data Model Communication Layer Component Layer Protocol Protocol Market Generation Transmission Domains Customer Premise Zones

14 14 Putting it all together... Use Case specific Power System (ICT) Architecures Use Case Use Case SGAM SGAM Control reactive power of unit Audit Network s Reporting and Statistics Business Objectives Polit. / Regulat.. Framework DMS Volt/Var Control SCADA Stabilize and Optimize Business Layer Function Layer Data Collector Outline of Usecase Functions Data Acquisition Control Supervision Interoperability Layers Information Layer Data Model Data Model IED Distributed Generation Communication Layer Protocol Protocol Market Component Layer Grid Generation Transmission Domains Customer Premises Zones Use Case Analysis Development Component Layer Development Business Layer Development Function Layer Development Information Layer Development Communication Layer Market Market Market Market Audit DMS Network s Volt/Var Reporting and Statistics Control SCADA Stabilize and Optimize Data Collector Data Acquisition Control Gateway HMI Data Collector IED CRM Computer DMS Computer HES Business objectives Business processes Economic and regulatory constraints Controller CRM Computer Audit Volt/Var Gateway Control DMS Computer SCADA HMI HES Data Collector Data IED Control Controller Acquisition Gateway Action Audit Voltage Measurement HMI Data Collector Voltage Measurement IED CRM Computer Acknow -ledge DMS Computer Reactive Power HES Setpoint Acknow -ledge Reactive Power Setpoint Controller CRM Computer IEC Gateway DMS Computer IEC HMI HES IEC ADSL IEC Data Collector GPRS IEC IEEE IED Controller IED Distributed Generation Grid G Grid G Grid G Grid G Grid HV MV LV HV MV LV HV MV LV HV MV LV Generation Transmission Customer Premise Generation Transmission Customer Premise Generation Transmission Customer Premise Generation Transmission Customer Premise Source: M/490 Reference Architecture WG, CEN-CENELEC-ETSI, 2011

15 15 Architecture Modeling in Smart Grids (cont d) Conclusion Best-case-scenario (no gaps!): Target architecture for the practical implementation of the use case Invest/expenditure may be compared against the business case However, more often: Missing standards (mappings between established standards) Legislative issues Missing methods/algorithms (e.g. achieving something in a given amount of time) Novel architecture-/control-concepts (multi-agent systems, self-organization etc.)? Do we have the right NFR (propagation of information, acceptance etc.)? Measuring/Testing these NFR? Wouldn t it be great to automate the modeling/design process? Beware of legacy systems! Taking into account additional domains (Heat, Gas, Mobility etc.) There is not the one future energy system architecture!

16 Source: Guidelines for conducting cost-benefit analysis of Smart Grid projects, European Commission, Architecture Modeling in Smart Grids (cont d) Concluding Conclusion (one more thing) Assessing algorithms with the right KPIs Timely performance Data frugality But we re in power systems, so it s important to look at: Increased sustainability Adequate capacity of transmission and distribution grids for collecting and bringing electricity to the consumers Adequate grid connection and access for all kinds of grid users Satisfactory levels of security and quality of supply Enhanced efficiency and better service in electricity supply and grid operation Effective support of transnational electricity markets by load flow control to alleviate loop flows and increased interconnection capacities Coordinated grid development through common European, regional and local grid planning to optimize transmission grid infrastructure Enhanced consumer awareness and participation in the market by new players Enable consumers to make informed decisions related to their energy to meet the EU Energy Efficiency targets Integrated ICT/power system KPIs experimental evaluation necessary!

17 17 References IEC, IntelliGrid Methodology for Developing Requirements for Energy Systems, Publicly Available Specification PAS 62559, Jose M. Gonza lez, Jo rn C. Trefke, Recommendations for the Description and Management of Use Cases for Smart Grids, DKE Deutsche Kommission für Elektrotechnik Elektronik Informationstechnik, CEN-CENELEC-ETSI Smart Grid Coordination Group, Smart Grid Reference Architecture, CEN-CENELEC-ETSI Smart Grid Coordination Group, First Set of Standards, IEC, Power system control and associated communications Reference architecture for object models, services and protocols, Technical Report TR 62357, European Commission, Guidelines for Conducting a Cost-Benefit Analysis of Smart Grid Projects, Report EUR EN, 2012.