1 Descriptions of Function

Transcription

1 Islanding to grid-connected transition Version 1.2 March 11, Descriptions of Function 1.1 Function Name Unintentional Islanding Transition 1.2 Function ID 1.3 Brief Description This use case describes the function when a disconnects from the area power system (AEPS) when there is a large disturbance internally or externally so that the can be isolated from the disturbance and continue the power supply to its loads in islanded mode. The large disturbance can be internal or external faults, loss of AEPS, and some other disturbances that the APS is no longer able to provide power supply with specified power quality. ORNL_UC_F-4.doc 1 3/20/2014

2 MICROGRID FUNCTIONAL USE CASES This is one of ten (10) use cases related to and operations between the area Electric Power System (AEPS) and Advanced s in connected, transition and islanded modes. operations and is described in terms of functions. The Functional Use Cases for Control and Operations of Advanced s are 1. Frequency 2. Voltage (grid-connected & islanding) 3. Grid-connected to islanding transition - Intentional 4. Grid-connected to islanding transition Unintentional 5. Islanding to grid-connected transition 6. Energy management (grid-connected & islanding) 7. Protection 8. Ancillary services (Grid-connected) 9. Black start 10. User interface and data management ORNL_UC_F-4.doc 2 3/20/2014

3 1.4 Narrative Usually there are large and rapid frequency and voltage deviations during a large disturbance and the needs to be capable of detecting such abnormal conditions and islanding from such disturbance, and more importantly, to be capable of disconnecting from the AEPS and maintaining its stability after the islanding transition. Once the switch detects abnormal condition based on its worn measurements of frequency and voltage, and possible combined with the measurement of current, the switch opens and the islands from the AEPS. The switch sends its status to the primary sources so that they can change their modes to frequency and voltage modes to restore the and maintains the stability of the. The switch also sends its status to the so that it can update the accordingly and send the update to all the actors. The sends the AEPS the status and updates the with the latest measurements and status as well. After the is stabilized, the calculates the economic es in the islanded mode and sends them to the, which distributes them to the actors to execute. 1.5 Actor (Stakeholder) Roles Grouping (Community), Group Description Actor Name Actor* - This use case. Actor Type (person, organization, device, system, or subsystem) Actor Description Area Electric Power System (AEPS) * System The electrical power system that normally supplies the through their point of common coupling. Area Natural Gas Supply (ANGS) System The natural gas pipeline system that supplies natural gas to the. Asset Switches (ASw) The ASw has the capability to disconnect assets within the (e.g. NCL) from the for purposes. The ASw can receive signals from the MC and can inform the MC of its status. ORNL_UC_F-4.doc 3 3/20/2014

4 Grouping (Community), Group Description Actor Name Actor* - This use case. Centralized Protection Controller (CPC) Critical Load (CL) * Market Operator (MO) ler (MC) * Actor Type (person, organization, device, system, or subsystem) System System System System Actor Description This is a central that is able to communicate with protective devices. It can operate to update settings, or coordinate the operation of protection in real time. This can be a standalone function, or it could be a part of the MCC. Loads within the having the highest priority of service. These loads will be served at the expense of all other loads in the and at the expense of any other service the could provide. The priority of loads within the critical loads is not distinguished. The MO accepts bids from assets, such as a MG, in its AEPS and es these assets to provide energy and ancillary services to ensure reliability for the AEPS. The MO may be part of the AEPS or may be a separate entity. A system that is able to the assets, e.g. opening/closing switches, changing reference points, changing generation/consumption levels, etc. Other than the functions specifically referenced below, this Use Case does not specify the objective of any of the ler functions. This Use Case does not specify how the signals are transferred or implemented in the assets. The communication and data acquisition of the ler. It collects real-time data from each individual actor, passes the data to the for the calculation of economic, receives the economic from the, and distributes them to the actors. It also s and coordinates the sources and loads to maintain system stability. ORNL_UC_F-4.doc 4 3/20/2014

5 Grouping (Community), Group Description Actor Name Actor* - This use case. Switch (MS) * Non-Critical Load (NCL) * Other Resource (OR) * Point of Common Coupling (PCC) * Primary Resource (PR) * Protection device (PD, w-com) (with communications) Protection device (PD, w/o-com) (without communications) Actor Type (person, organization, device, system, or subsystem) Actor Description A switch at the point of common coupling of the and the AEPS. The switch has the capability to detect the loss of power from the AEPS and disturbances in the AEPS. The MS can open and close automatically and on command from the MC and can inform the MC of its status. Loads within the having the lowest priority of service. These loads may be left unserved in favor of Critical Loads. The priority of loads within the critical loads is not distinguished. All energy resources in the except for the primary resources. OR could be a generator, energy storage system, or a load. The electrical interface between the AEPS and the. The energy resources responsible for frequency and voltage regulation. PRs could be a generator, an energy storage system, or lable load. This is a relay type device that is able to interrupt fault current and communicates with other devices or the MCC. An example would be a protective relay that has communication with the MCC. This is a relay type device that is able to interrupt fault current and operates in isolation. Examples include relays without the ability to communication, and fuses. Protection relay (PR) The device to detect and clear a fault. Switching device (SD, w-com) (with communications) This is a switching device that communicates with other devices or the MCC/CPC. ORNL_UC_F-4.doc 5 3/20/2014

6 Grouping (Community), Group Description Actor Name Actor* - This use case. Switching device (SD, w/o-com) (without communications) Actor Type (person, organization, device, system, or subsystem) Actor Description This is a switching device that does not communicate with other devices or the MCC/CPC. 1.6 exchanged Object Name Measurements and status switch status Object Description Includes voltage, current and/or power measured at each actor, and the status of the actor, including on/off status, operation modes, and other actor operation status indicators. The sent from to individual actors, including sources, loads, switch, and protection devices. The the economic from the, and send signals to the actors between the two economic es to maintain the system stability during islanded operation mode. The include the source mode, real and reactive power, and load levels for lable loads. The source mode determine if a source is operated as a primary source that s the frequency and/or voltage of the during islanded operation condition or as other source. It also includes the frequency and voltage setting point. A signal sent by switch indicating the status of the switch. ORNL_UC_F-4.doc 6 3/20/2014

7 Object Name status Object Description sent by to area power system indicating the operation status of the. 1.7 Activities/Services Activity/Service Name Critical Load Service Activities/Services Provided The will provide electrical power service to all critical loads. 1.8 Contracts/Regulations Contract/Regulation IEEE Std Series Interconnection Agreement Public Utility Net Metering Regulations Impact of Contract/Regulation on Function Standard for Interconnection to the area EPS at the PCC Typical Provisions include: Construction, Interconnection, Operations, Safety & Maintenance, Access, Exterior AC Disconnect Switch / Isolation, Conflicts in Agreements, Disconnection, Customer Generator Billing & Payment, Insurance, Customer-Generator Indemnification, Limitation of Liability, Termination, Permanent Disconnection, Survival Rights, Assignment/Transfer of Ownership of the Customer-Generator Facility As applicable, where the exports to area EPS ORNL_UC_F-4.doc 7 3/20/2014

8 Contract/Regulation ISO Market Rules Impact of Contract/Regulation on Function As applicable, where the participates in markets Policy From Actor May Shall Not Shall Description (verb) To Actor Obligation to serve Area Electric Power System (AEPS) X Provide power on demand at PCC Operator Constraint Type Description Applies to 2 Step by Step Analysis of Function 2.1 Steps to implement function Name of Sequence Preconditions and Assumptions ORNL_UC_F-4.doc 8 3/20/2014

9 Actor/System//Contract Preconditions or Assumptions Steps Name of Sequence NOTE: The step-by-step table and bubble diagram also show the operations before and after the intentional islanding transition. # Event Primary Actor Name of Description of Producer Receiver Name of Info Exchanged Additional Notes # Triggering event? Identify the name of the event. 1 What other actors are primarily responsible for the? Actors are defined in section1.5. Label that would appear in a process diagram. Use action verbs when naming activity. Describe the actions that take place in active and present tense. The step should be a descriptive noun/verb phrase that portrays an outline summary of the step. If Then Else scenarios can be captured as multiple Actions or as separate steps. What other actors are primarily responsible for Producing the information? Actors are defined in section1.5. What other actors are primarily responsible for Receiving the information? Actors are defined in section1.5. (Note May leave blank if same as Primary Actor) Name of the information object. objects are defined in section 1.6 Elaborate architectural issues using attached spreadsheet. Use this column to elaborate details that aren t captured in the spreadsheet. 0.0 Bid submission Market Operator bid 1 Note A triggering event is not necessary if the completion of the prior step leads to the transition of the following step. ORNL_UC_F-4.doc 9 3/20/2014

10 # Event Primary Actor Name of Description of Producer Receiver Name of Info Exchanged Additional Notes 0.1 Receive market Market Operator Market 0.2 Calculate economic economic 1.0 Update measurement All actors Measurements and status 1.1 Update economic economic 1.2 Update 1.3 Send All actors 1.4 Execute All actors ORNL_UC_F-4.doc 10 3/20/2014

11 # Event Primary Actor Name of Description of Producer Receiver Name of Info Exchanged Additional Notes 1.5 Update measurement s Measurements and status 2.0 Grid disturbance detection switch 2.1 Open switch switch 2.2 Send switch status switch switch Primary sources switch status 2.3 Frequency and voltage execution Primary sources 2.4 Send switch status switch switch switch status ORNL_UC_F-4.doc 11 3/20/2014

12 # Event Primary Actor Name of Description of Producer Receiver Name of Info Exchanged Additional Notes 3.0 Update 3.1 Send All actors 3.2 Execute All actors 3.3 Send status APS status 4.0 Update measurement All actors Measurements and status 4.1 Update measurement s Measurements and status 4.2 Calculate economic economic ORNL_UC_F-4.doc 12 3/20/2014

13 # Event Primary Actor Name of Description of Producer Receiver Name of Info Exchanged Additional Notes 4.3 Send economic economic 4.4 Update 4.5 Send All actors Post-conditions and Significant Results Describe conditions that must exist at the conclusion of the Function. Identify significant items similar to that in the preconditions section. Actor/Activity Post-conditions Description and Results 2.2 Architectural Issues in Interactions FUTURE USE ORNL_UC_F-4.doc 13 3/20/2014

14 2.3 Diagram Area Power System Switch Market Operator Primary Sources Other Sources Loads ORNL_UC_F-4.doc 14 3/20/2014

15 3 Auxiliary Issues 3.1 References and contacts ID Title or contact Reference or contact information [1] [2] 3.2 Action Item List FUTURE USE ID Description Status [1] [2] 3.3 Revision History ORNL_UC_F-4.doc 15 3/20/2014

16 No Date Author Description Nov13 Y. Xu Initial use case Feb 14 J. Reilly 1.3 (insert), 1.7, Mar 14 Y. Xu 1.6 Exchanged ORNL_UC_F-4.doc 16 3/20/2014