UC-GR-2

1. Description of the Use Case

1.1. Name of the Use Case

Use case identification | ID | Area /Domain(s)/Zone(s)| Name of the Use Case | | — | — | — | | UC-GR-2| Area: Energy system
Domains: Distribution, DER, Customer Premises
Zones: Station, Operation
| PMU data integration into SE tool |

Notes:

• ID - uniqe 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.|Date |Name of author(s)|Changes|Approval status| |— |— |— |— |— | |0.1|17th June 2020|Themistoklis Xygkis, Panagiotis Pediaditis, Stavroula Tzioka, Eleni Daridou, Dimitris Stratogiannis|Initial creation|Draft|

1.3. Scope and Objectives of Use Case

Scope and objectives of use case

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.
• Realted business case(s) - optional

1.4. Narrative of Use Case

Short description Measurement data obtained from the installed PMUs are integraded in the State Estimation tool and used to enhance the network observability. The installation of PMUs at selected buses is sure to upgrade the overall metering infrastructure of the network, since they record synchronized measurements of bus voltage phasors as well as a number of line current phasors—all of which are independent of each other and count as individual measurements. Yet, their proper utilization via the SE tool is a challenging task due to a) the intense discrepancies in update rates between conventional and PMU measurements, b) the provision of current measurements which often lead to various numerical problems, and c) the contrast between the large weighting factors linked to PMU measurements compared to the much lower ones linked to pseudo-measurements, which usually raises ill-conditioning issues. The goal is to ensure that the integration of PMU data will be smooth and all the aforesaid problems will be circumvented.

Complete description A measurement set, composed of actual and historical measurement data obtained from the dispersed metering devices (AMR, GIS, SCADA, PMUs) installed throughout the network, is available to the DSO for real-time operation purposes. The aforementioned data refer to a) synchronised measurements of bus voltage phasors and line current phasors (magnitude and angle) and b) conventional measurements of power flows and voltage magnitudes at the top of distribution feeders, power injections from distributed generation units, and load pseudo-measurements for aggregated consumer demand at MV/LV transformer level. Given that the network model (topology) is known with a good degree of certainty, the state estimation tool ensures that the network is observable based on the available measurement set, reconciles the PMU data with the conventional measurements, and, subsequently, calculates the estimated state vector, that is, the voltage magnitudes and angles of all network buses. Given the successful integration and use of the PMU data in the SE tool, the overall performance of the SE tool will be enhanced; the network state will be calculated with increased precision compared to conventional-measurements-only scenarios (uc-GR-1), and high quality real-time operational standards for distribution management applications will be met.

1.5. Key Performance Indicatiors (KPI)

Notes: Can be left blank now

1.6. Use case conditions

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

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

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

2. Diagrams of Use Case

3. Technical Details

3.1. Actors

Notes:

• Actor Type - Device/ Sytem/ Person

3.2. References

OPTIONAL - you can leave it blank

4. Step by Step Analysis of Use Case

4.1. Overview of Scenarios

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 - PMU data integration

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

Notes

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

6. Requirements (optional)

PMU field installation

7. Common Terms and Definitions

8. Custom Information (optional)