UC-GR-4

Frequency support by the distribution network

1. Description of the Use Case

1.1. Name of the Use Case

Use case identification

IDArea /Domain(s)/Zone(s)Name of the Use Case
UC-GR-04Area: Energy system/
Domains: Distribution,Transmission, DER, Customer Premises/
Zone: Station,Operation
Frequency support by the distribution network

Notes:

  • ID - unique identification label: DE-1/GR-3/IT-2

  • Area /Domain(s)/Zone(s) - placement of the use case in the SGAM domains and zones. It can be left blank if you are not sure.

1.2. Version Management

Version management

Version No.DateName of author(s)ChangesApproval status
0.117th June 2020Panagiotis Pediaditis, Stavroula Tzioka, Eleni Daridou, Dimitris Stratogiannis, Themistoklis XygkisInitial creationDraft

1.3. Scope and Objectives of Use Case

Scope and objectives of use case

ScopeThe scope of the UC is to examine the operational use of flexibility tools in order to reduce the possibility of negative effects on the distribution in the case of a frequency support request by the transmission system.
Objective(s)To achieve better operating conditions of the distribution network in the case of a frequency restoration reserve activation request by the TSO.
Related business case(s)add text

Notes:

  • Scope - describes the aims and boundaries of the use case in a short, precise text.
  • Objective(s) - goals of the use case, in form of bullet points and a short headline.
  • Related business case(s) - optional

1.4. Narrative of Use Case

Short description Various types of flexible loads -aggregated for the scope of the Use Case- react to network tariffs sent by the DSO, so that frequency restoration request from the TSO is adequately handled. More in detail, customers with flexible loads will respond to such requests and the DSO will use flexibility tools to coordinate their response aiming at achieving the frequency support objective while ensuring distribution network operational safety. As in the previous Use Cases the state of the system is provided by the state estimation tool.

Complete description Customers with flexible loads are connected to the distribution network and their loads are considered aggregated for the scope of the UCs regarding their management in the MV level. State of the network is known with a good degree of certainty based on the available measurements and the topology via the AMR, GIS and SCADA data. A frequency support activation request from the TSO arrives at the customers with flexible loads. The request is also communicated to the DSO technical platform via an API and the information is shared with the appropriate tools and services. The DSO calculated and communicated to the customers the appropriate network tariffs that reflect the situation of the network. The flexible loads react to these tariffs and respond to the frequency support request appropriately.

add text - longer narrative from user viewpoint about what happens how, where, when, why and under which assumptions. It has to be written in a way that it can also be understood by non-experts.

1.5. Key Performance Indicatiors (KPI)

IDNameDescriptionReference to mentioned use case objectives
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Notes: Can be left blank now

1.6. Use case conditions

AssumptionsPrerequisites
Customers' consent required for participation in the flexibility mechanism, Customers are rational, Part of the load is flexible, State of the network is known with a good degree of certaintySimulation of TSO, Dynamic network charging is allowed, Smart metering is installed, Smart appliances can perform load shifting, DSO systems (e.g.AMR, GIS, SCADA) being operational

Customers are rational, Part of the load is flexible, State of the network is known with a good degree of certainty Notes:

  • Assumptions - general presumptions about conditions or system configurations (e.g. customer’s consent required for some steps; simulation of TSO)
  • Prerequisites - specify which requirements have to be met so that the basis scenario use case can be successfully accomplished.

1.7. Further information to the use case for classification/mapping

OPTIONAL - you can leave it blank

Relation to other use cases
include uc-GR-1 and potentially uc-GR-2
Level of depth
detailed
Prioritisation
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Generic, regional or national relation
add text
Nature of the use cases
technical, market, test
Further keywords for classification
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Notes:

  • Relation to other use cases - relation to other use cases in the same project or thematic area. Possible relation types are for instance include, extend, invoke, or associate.
  • Level of depth - reflects the degree of specialisation of the use case. Although no common notation is settled, descriptions like high level use case, generic, detailed, or specialised use case are often used.
  • Prioritisation - helps to rate the use cases in a project from very important to nice-to-have with labels like obligatory/mandatory or optional which have to be agreed upon beforehand.
  • Generic, regional or national relation - for the purpose of generalisation if use case is applied to areas where restictions by law or silimiar issues occur.
  • Nature of the use cases - describes the viewpoint and field of attention like technical, political, business/market, test, etc.

1.8. General remarks

General remarks
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- add text
- add text

Notes: Add any remarks which do not fit in any other category

2. Diagrams of Use Case

Diagram of Use Case Sequence diagram

3. Technical Details

3.1. Actors

Actor NameActor TypeActor DescriptionFurther information specific to this Use Case
AggregatorPersonEntity that aggregates the flexibility offers on the market and provide them to DSO in case of needs for the grid
AMRSystemAutomatic Meter Reading system
Commercial customerPersonEnd user to denote a typical commercial electricity consumption with the capability of load flexibility provision through a contract with an Aggregator
DMSSystemDistribution Management System
DSOPersonDistribution System Operator, the entity responsible for the safe and secure operation and management of the distribution system; for data management associated with the use of the distribution system; for procurement of flexibility services using optimization algorithms and the Platone DSO Technical Platform.
DSO Data ServerSystemDatabase containing data from AMR, DMS & SCADA
DSOTPSystemDSO Technical Platform
GISSystemGeographical Information System
PMUDevicePhasor Measurement Unit
RESSystemRenewable Energy Source
Residential customerPersonEnd user to denote a typical residential electricity consumption with the capability of load flexibility provision through a contract with an Aggregator
SCADADeviceSupervisory Control And Data Acquisition system
TSOPersonTransmission System OperatorSimulated entity to trigger the use case

Notes:

  • Actor Type - Device/ Sytem/ Person

3.2. References

OPTIONAL - you can leave it blank

No.References TypeReferenceStatusImpact on Use CaseOrganistaor / OrganisationLink
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4. Step by Step Analysis of Use Case

4.1. Overview of Scenarios

No.Scenario NamePrimary ActorTriggering EventPre-ConditionPost-Condition
1Frequency support request resolvedTSOTSO sending a fequency support requestDistribution network observabilityFrequency support request resolved

Notes This part describes the possible scenarios of the use case. The scenarios should comply with the sequence diagrams in Sect. 2 of the template, so that every step describes one part of a communication or action. Apart from a normal success scenario, different failure scenarios or alternatives can be included to describe situations where preconditions are not satisfied or unwanted states are attained.

  • Primary Actor - the first actor appearing in the scenario at the incident causing the scenario to begin.
  • Triggering Event - the incident causing the scenario to begin.
  • Pre-Condition - indicates which terms have to be fulfilled for the scenario to be executed.
  • Post-Condition - indicates which terms should be valid after the scenario. TIt can also specify whether a scenario has been successfully completed or not.

4.2. Steps – Scenarios

Scenario Name: No. 1 - Frequency support request resolved

Step No.Event.Name of Process/ ActivityDescription of Process/ Activity.ServiceInformation Producer (Actor)Information Receiver (Actor)Information ExchangedRequirements, R-ID
1TSO needs frequency supportFrequency support requestFrequency support request sent to the AggregatorCREATETSOAggregatorI-08
2TSO needs frequency supportFrequency support requestFrequency support request communicated to the DSOCREATETSODSOI-08
3DSO receives frequency support request from TSOFrequency support requestFrequency support request sent to the DSOTPREPORTDSODSOTPI-08
4Frequency support request recieved by DSOTPTariffs retrievalTariffs are sent to the DSOCREATEDSOTPDSOI-06
5Tariffs retrievalTariffs communicationTariffs are communicated to the AggregatorREPORTDSOAggregatorI-06
6Tariffs communicationSetpoint sent to Residential CustomerSending setpoint to the flexibility loadCREATEAggregatorResidential consumerI-07
7Tariffs communicationSetpoint sent to Commercial CustomerSending setpoint to the flexibility loadCREATEAggregatorCommercial consumerI-07
8Tariffs communicationSetpoint sent to RESSending setpoint to the RES producerCREATEAggregatorRESI-07
9noneData AquisitionNew Distribution Network state (Distribution Network state updated following the Aggregator’s response)REPORTPMUDSOTPI-04
10noneData AquisitionNew Distribution Network state (Distribution Network state updated following the Aggregator’s response)REPORTSCADA,DMS,GIS,AMRDSO Data ServerI-01
11New Distribution Network stateData AquisitionNew Distribution Network stateREPORTDSO Data ServerBAPI-01
12New Distribution Network stateData VerificationAll data received gets verified and secured via blockchain technologyEXECUTEBAPBAP
13New Distribution Network stateData AcquisitionVerified and secured data is delivered to the DSOTPREPORTBAPDSOTPI-03
14New Distribution Network stateData AquisitionNew Distribution Network stateREPORTDSOTPDSOI-02

Notes This part describes the possible scenarios of the use case. The scenarios should comply with the sequence diagrams in Sect. 2 of the template, so that every step describes one part of a communication or action. Apart from a normal success scenario, different failure scenarios or alternatives can be included to describe situations where preconditions are not satisfied or unwanted states are attained.

  • Event - Event triggering a step, specific for that use case.
  • Name of Process/ Activity - general classification of process/activity (e.g. data aquisition).
  • Description of Process/ Activity - more detailed description of the step.
  • Service - addresses the nature of the information flow. Possible: GET (The information receiver obtains information from the information producer after an implicit request.), CREATE (The information producer creates an information object.), CHANGE (The information producer performs an update of the information at the information receiver’s.), DELETE (The information producer deletes information of the receiver.), CANCEL/CLOSE (A process is terminated.), EXECUTE (An action or service is performed.), REPORT (The information producer supplies information of its own account.), TIMER (The actor which represents both information producer and receiver has to enforce a waiting period.), REPEAT (A number of steps has to be repeated until a break condition (stated in the field Event) is satisfied. The contemplated steps have to be added in parentheses.).
  • Information Producer and Receiver (Actor) - actors from actor list in section 3.1
  • Information exchanged (IDs) - ID of the information defined further in section 5

5. Information Exchanged

Information exchanged IDName of InformationDescription of Information ExchangedProtocol
I-01MeasurementsMeasurements from the Distribution Network (voltage magnitudes, active and reactive power injections/flows)TCP/IP, IP over GPRS
I-02State VectorVoltage magnitudes and angles of all network buses
I-04PMU MeasurementsMeasurements from PMUs (e.g. voltage magnitudes, voltage phasors, current phasors)MQTT
I-06Network tariffsNetwork tariffs that reflect the Disribution Network stateIP
I-07SetpointSetpoint for adjustment of flexible load/RES productionIP
I-08Frequency support requestFrequency support request from the TSOIP

Notes

  • Information exchanged ID - unique number (I-01,I-02…) for identification
  • Requirements to information data - optional, defined in section 6

6. Requirements (optional)

7. Common Terms and Definitions

TermDefinition

8. Custom Information (optional)

KeyValueRefers to Section