1 Descriptions of Function

Transcription

1 Distributed Energy Resource Controller Reconfigure s in response to Faulted Segment with Islanding 1 Descriptions of Function Version 1.2 January 13, 2010 This function describes the sequence of activities required for fault isolation and provides for the creation of islands behind the fault on isolated sections of the distribution feeder fed by local generation. 1.1 Function Name Distributed Energy Resource Controller Reconfigure s in Response to Faulted Segment with Islanding 1.2 Function ID identification number of the function 1.3 Brief Description This function describes the sequence of activities required for handling a fault condition on a distribution feeder. This particular scenario provides not only fault isolation, but provides for the creation of islands behind the fault on isolated sections of the distribution feeder fed by local generation. While this scenario holds many points in common, it differs from the existing EPRI use case Controlled Islanding in that it specifically addresses islands created below the substation. 1.4 Narrative The presence of generation and storage units in the distribution grid create the possibility of islands. While most of the effort to date has been in mechanisms to suppress the creation of islands, an ideal solution would encourage viable islands in fault conditions, thus enhancing system availability for the greatest possible number of customers. There are considerable technical hurdles to this however. The smaller the island, the harder it is to maintain a perfect match between generation and load. Further, the weaker the system, the more difficult it is to keep voltage and frequency in an acceptable range. While these problems make the maintenance of an island over a long period of time increasingly difficult, they might be a viable solution for isolating some segment of customers from momentary interruptions and other outages that last between minutes and Fault Response Island Operation V1.2.doc 1 January 14, 2010

2 hours. This approach introduces other issues that must be addressed as well. Left to its own devices, it is inevitable that the islanded system will drift out of phase with the primary electrical power system. This will require switching equipment that can detect the out of phase condition and prevent accidentally closing into it. It will also require a mechanism bring the two systems close enough together to reduce the phase angle difference to a point where closing the switch will not create a hazardous situation or provide undue stress to connected equipment. As detailed by this use case, the first step in creating a viable island is identifying it. This will require an approach similar to the Remedial Action Schemes used by transmission systems. The primary difference is that due to the dynamic nature of the problem coupled with the number of possible combinations, this process must be a continuous one done in real time. The system will have to evaluate both controlled and uncontrolled segments, as the potential island could result from both controlled and uncontrolled (autonomous) switching operations (i.e. fuse). There are currently systems available that can manage the creation of small islands within a larger distribution networks. Typically deployed on small isolated power systems (like remote refineries), they depend on a combination of direct load control of large motors in conjunction with switching operations to match the load to the available generation. In a modern distribution system a similar approach can be taken. The presence of an Advanced Metering Infrastructure (AMI) system allows additional opportunities. First, the connect/disconnect switch can be used to drop the load on a network segment. This allows finer control that simply dropping an entire segment. Second, the load break device in many AMI meters can act as a programmable circuit breaker. This allows the Distributed Energy Resource Controller () to send commands limiting the load for each meter. It is expected that the AMI meter would in turn communicate this limit to the in home thermostat, or even home automation controls. This load limiting would help improve the stability of the network by limiting the total load to a level that provided some margin in the system. In addition, the would reconfigure the DES units to support system stability. In the event the outage on the primary electrical system persists, the would continue to evaluate the situation and continue to take necessary action. Generally, this would entail further reducing the island, but could entail activating additional segments in the event that the system was approaching an off peak period. 1.5 Actor (Stakeholder) Roles Describe all the people (their job), systems, databases, organizations, and devices involved in or affected by the Function (e.g. operators, system administrators, technicians, end users, service personnel, executives, SCADA system, real-time database, RTO, RTU, IED, power system). Typically, these actors are logically grouped by organization or functional boundaries or just for collaboration purpose of this use case. We need to identify these groupings and their relevant roles and understand the constituency. The same actor could play different roles in different Functions, but only one role in one Function. If the same actor (e.g. the same person) does play multiple roles in one Function, list these different actor-roles as separate rows. Fault Response Island Operation V1.2.doc 2 January 14, 2010

3 Grouping (Community), DER Actors Group Description Actors used in the DER Use Case Actor Name Actor Type (person, device, system etc.) Actor Description AMI Interface Device Interface between AMI system and other field systems. The assumption is that the AMI interface would not require communications to travel all the way to the AMI Head end system and back to the field. Ideally, the AMI interface allows peer to peer communications to AMI network devices in the field with distribution automation devices and systems also physically located in the field. Distributed Energy Resource Controller () Distribution Management Electrical Power (EPS) Fault Identification, Location, Isolation and Service Restoration Application (FILISR) Load-shedding Device (AMI Unit) located in the substation that coordinates Distributed Energy Resources. Monitors operations schedules, status and controls operation of equipment. Provides real-time data to the system demand modeler and control room operator All of the equipment required to deliver quality electrical power to the end user at utilization voltage that uses automation to aid and increase speed of recovery of fault events. Involved during entire fault process from identification to system restoration Device Sheds load to balance the load-generation within an area before islanding, generally a component of the AMI system OMS Operations Management Collection of IEDs and or Bay controllers responsible for the coordination and execution of actuators and other devices primarily dedicated to protection SCADA that monitors load control as well as providing forecast and real-time distribution information to the system demand modeler and control room operator Device Electrical Actuators, control systems and protection equipment involved in the bulk Fault Response Island Operation V1.2.doc 3 January 14, 2010

4 Grouping (Community), DER Actors Group Description Actors used in the DER Use Case Actor Name Actor Type (person, device, system etc.) Actor Description transformation of power from transmission voltages to subtransmission or distribution voltages WOMS Work Order Management. Used to schedule work for Operations including scheduled outages. Bay Controller Device An Intelligent Electronic Device that coordinates or controls one or more subordinate IEDs Remedial Action Scheme Function ( RAS) of the that is responsible for identifying and validating viable alternative network configurations based on likely contingencies. Device Equipment controlled by. Could include generation and load devices. Device can be Storage, Wind, Solar. IED Device Intelligent Electronic Device. CPU and supporting subsystems that receives sensor data from one or more sensors and uses that data to coordinate and control one or more actuators (i.e. breaker, LTC, capacitor bank etc) Power Flow Monitoring Availability Monitor Network AMI Subsystem Subsystem of the AMI Network of the that monitors power flow on the associated line segments. of the that monitors the availability of the Equipment and s on the associated system. of the that predicts equipment scenarios that will fulfill the requirements from the scenarios developed from the other s AMI Endpoints Device AMI Meters or endpoints on the distribution system Fault Response Island Operation V1.2.doc 4 January 14, 2010

5 Grouping (Community), DER Actors Group Description Actors used in the DER Use Case Actor Name Actor Type (person, device, system etc.) Actor Description Replicate this table for each logic group. 1.6 exchanged Describe any information exchanged in this template. Object Name Power Flow of Line Segments Calculations of Balanced Segment/Segmentation Calculations of Balanced Segments from load shedding/current limiting Scenario Ratings according to SAIDI, SAIFI and critical loads Emergency Equipment Commands for Additional s for Balanced Operation for scenario Appropriate Fault Detection RAS Islanding Scenario Orders Object Description Power flow of the associated line segments that are being monitored from the Calculations of Balanced Segment/Segmentation Calculations of Balanced Segments from load shedding/current limiting scenarios Scenario Ratings according to SAIDI, SAIFI and critical loads Emergency Equipment Commands to complete the requirements for the given scenario. Additional system components ( Equipment, Bay Controllers, IEDs, etc.) for balanced operation for the scenario Appropriate for the Bay Controllers and IEDs Detection of a fault on the electric power system Altered protection settings appropriate to island operation, as well as adjusted ranges appropriate to island operation Fault Response Island Operation V1.2.doc 5 January 14, 2010

6 Object Name Transfer Trip Signal for s Emergency Load Shed/Current Limiting Orders Optimized Schedule Optimal Optimal Setting Optimized Charge/Discharge Commands/Schedule for DER Storage Units Optimized Commands/Schedule Optimal Optimal Setting Scheduling of maintenance work order Maintenance Order Affected Segment and timeframe RAS Islanding Scenario Orders Load Shed/Current Limiting Orders Ready for island operation Equipment Commands Object Description Transfer Trip Signal for to open up the s Emergency Load Shed/Current Limiting Orders for the AMI Endpoints to help relieve some of the stress off the electrical power system profiles for a select group of Units on a section of the EPS. profiles for a section of the EPS. Settings for the on a section of the EPS. Charge/discharge profiles for a select group of Storage Units on a section of the EPS. profiles for a select group of Units on a section of the EPS. profiles for the Storage Units for a section of the EPS. Settings for the on a section of the EPS. Scheduling of maintenance work orders Maintenance Order Affected Segment and timeframe RAS Islanding Scenario Orders Load Shed/Current Limiting Orders for the AMI Endpoints to help relieve some of the stress off the electrical power system The system is ready for island operation Equipment Commands to operate a device. Fault Response Island Operation V1.2.doc 6 January 14, 2010

7 Object Name Object Description 1.7 Activities/Services Describe or list the activities and services involved in this Function (in the context of this Function). An activity or service can be provided by a computer system, a set of applications, or manual procedures. These activities/services should be described at an appropriate level, with the understanding that sub-activities and services should be described if they are important for operational issues, automation needs, and implementation reasons. Other sub-activities/services could be left for later analysis. Activity/Service Name Activities/Services Provided 1.8 Contracts/s Identify any overall (human-initiated) contracts, regulations, policies, financial considerations, engineering constraints, pollution constraints, and other environmental quality issues that affect the design and requirements of the Function. Contract/ Impact of Contract/ on Function Policy From Actor May Shall Not Shall Description (verb) To Actor Fault Response Island Operation V1.2.doc 7 January 14, 2010

8 Constraint Type Description Applies to 2 Step by Step Analysis of Function Describe steps that implement the function. If there is more than one set of steps that are relevant, make a copy of the following section grouping (Steps to implement function, Preconditions and Assumptions, Steps normal sequence, Post-conditions) and provide each copy with its own sequence name. 2.1 Steps to implement function Sequence this sequence Preconditions and Assumptions Describe conditions that must exist prior to the initiation of the Function, such as prior state of the actors and activities Identify any assumptions, such as what systems already exist, what contractual relations exist, and what configurations of systems are probably in place Identify any initial states of information exchanged in the steps in the next section. For example, if a purchase order is exchanged in an activity, its precondition to the activity might be filled in but unapproved. Actor///Contract Preconditions or Assumptions Steps Sequence Describe the normal sequence of events, focusing on steps that identify new types of information or new information exchanges or new interface issues to address. Should the sequence require detailed steps that are also used by other functions, consider creating a new sub function, then Fault Response Island Operation V1.2.doc 8 January 14, 2010

9 referring to that subroutine in this function. Remember that the focus should be less on the algorithms of the applications and more on the interactions and information flows between entities, e.g. people, systems, applications, data bases, etc. There should be a direct link between the narrative and these steps. # Event Primary Actor Info # 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) 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. Reference the applicable containing this data exchange. Only one environment per step. 1 Normal Operation Power Flow Monitoring Monitors Power Flow Power Flow Monitoring monitors power flows of feeders within its scope Power Flow Monitor Power Flow Monitor Power Flow of Line Segments 2.1 RAS Continuous Calculations of Balanced Segment/Seg mentation RAS continually calculates a series of instantaneous balanced scenarios based on possible segmentation schemes RAS RAS Calculations of Balanced Segment/Segme ntation Continuous monitoring of system and updating of contingent islanding operations 1 Note A triggering event is not necessary if the completion of the prior step leads to the transition of the following step. Fault Response Island Operation V1.2.doc 9 January 14, 2010

10 Info 2.2 RAS Continuous Calculations of Balanced Segments from load shedding/curr ent limiting RAS continually calculates a series of achievable balanced scenarios with load shedding/current limiting based on possible segment schemes RAS RAS Calculations of Balanced Segments from load shedding/current limiting Possible segmentation schemes are limited by the availability of phase angle matching switching gear 3 Availability Monitor Rates according to SAIDI, SAIFI and critical loads Availability Monitor rates scenarios by SAIDI, SAIFI impacts, with consideration of critical loads Availability Monitor Availability Monitor Scenario Ratings according to SAIDI, SAIFI and critical loads 4.1 Network Determining breakers Network determines Equipment which should be tripped in event of emergency to create balanced island areas Network Network Emergency Equipment Commands for 4.2 Network Additional s Network determines additional system operations that will need to be performed to balance island areas Network Network Additional s for Balanced Operation for scenario Fault Response Island Operation V1.2.doc 10 January 14, 2010

11 Info 5 Create Creates appropriate profiles for Bay Controllers and dependent IEDs as required and pushes them to affected Bay Controllers and dependent IEDs as required Bay Controllers and IEDs Appropriate Includes load shedding and AMI Current Limiting 6.1 Fault Detected Fault is detected is detected by the and Command Signals are sent to the Equipment Equipment Fault Detection 6.2 FLISR FLISR Fault is detected and communicated to FLISR Fault Detection RAS Islanding Scenario Accepted determines the appropriate RAS Islanding Scheme based on maximizing system indices with instantaneous trip (no delay for load shedding and pushes orders out RAS Islanding Scenario Orders Altered protection settings appropriate to island operation, as well as adjusted ranges appropriate to island operation Fault Response Island Operation V1.2.doc 11 January 14, 2010

12 Info Transfer Trip initiates transfer trip for DER devices on affected segments and delivers it to Transfer Trip Signal for DER Devices Execute Actions effects protection scheme. s Transfer Trip Signal for DER Devices 7.1 RAS Calculate appropriate Scheme RAS calculates appropriate scheme and generates Load Shed, current limit orders based on the loss of generation on faulted segments and passes them to AMI Subsystem RAS AMI Subsystem Emergency Load Shed/Current Limiting Orders Load shed and current limiting is still enacted to provide a margin for operation and provide for security margin 7.2 AMI Subsystem Sends AMI Commands AMI Subsystem sends commands to the AMI Endpoints AMI Subsystem AMI Endpoints Emergency Load Shed/Current Limiting Orders 8.1 Charge Schedule generates storage charge/discharge orders based on new generation and loading profile Optimized Charge/Discharg e Schedule for DER Storage Units Fault Response Island Operation V1.2.doc 12 January 14, 2010

13 Info 8.2 Schedule calculates Optimized Schedule based on new generation and loading profile Optimized DER Device Schedule 8.3 regulation Profile generates voltage regulation profiles based on new generation and loading profile Optimal 8.4 Setting calculates Optimal Setting for the day based on new generation and loading profile Optimal Setting 8.5 Charge/Disch arge Schedule Push pushes Optimized Charge/Discharge Schedule for DER Storage Units to DER Device (storage units). Storage Unit Optimized Charge/Discharg e Commands/Sche dule for DER Storage Units Fault Response Island Operation V1.2.doc 13 January 14, 2010

14 Info Storage Units Storage Responds Accordingly The DER Units Respond Accordingly Storage Unit Storage Unit Optimized Charge/Discharg e Commands/Sche dule for DER Storage Units 8.6 Schedule Push pushes Optimized Schedule to (generation units). Unit Optimized DER Device Commands/Sche dule Units Responds Accordingly The DER Units Respond Accordingly Unit Unit Optimized DER Device Commands/Sche dule 8.7 Profile Push pushes Optimal to the as appropriate Optimal Responds Accordingly The Respond Accordingly Optimal Fault Response Island Operation V1.2.doc 14 January 14, 2010

15 Info 8.8 Setting Profile Push pushes Optimal Setting to the as appropriate Optimal Setting Responds Accordingly The Responds Accordingly Optimal Setting 9 Power Flow Monitoring Power Flow Reports Power Flow Monitoring function reports balance and flows Power Flow Monitoring Power Flow Monitoring Power Flow of Line Segments 10 Operation as an embedded island continues operation with an embedded island 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. Describe any significant results from the Function Actor/Activity Post-conditions Description and Results Fault Response Island Operation V1.2.doc 15 January 14, 2010

16 2.2 Steps to implement function Sequence this sequence Preconditions and Assumptions Describe conditions that must exist prior to the initiation of the Function, such as prior state of the actors and activities Identify any assumptions, such as what systems already exist, what contractual relations exist, and what configurations of systems are probably in place Identify any initial states of information exchanged in the steps in the next section. For example, if a purchase order is exchanged in an activity, its precondition to the activity might be filled in but unapproved. Actor///Contract Preconditions or Assumptions Steps Sequence Describe the normal sequence of events, focusing on steps that identify new types of information or new information exchanges or new interface issues to address. Should the sequence require detailed steps that are also used by other functions, consider creating a new sub function, then referring to that subroutine in this function. Remember that the focus should be less on the algorithms of the applications and more on the interactions and information flows between entities, e.g. people, systems, applications, data bases, etc. There should be a direct link between the narrative and these steps. Fault Response Island Operation V1.2.doc 16 January 14, 2010

17 Info # Triggering event? Identify the name of the event. 2 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) 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. Reference the applicable containing this data exchange. Only one environment per step. 1 Normal Operation A section is taken out of service for maintenance Power Flow Monitoring Monitors Power Flow Power Flow Monitoring monitors power flows of feeders within its scope Power Flow Monitor Power Flow Monitor Power Flow of Line Segments 2.1 RAS Continuous Calculations of Balanced Segment/Seg mentation RAS continually calculates a series of instantaneous balanced scenarios based on possible segmentation schemes RAS RAS Calculations of Balanced Segment/Segme ntation Continuous monitoring of system and updating of contingent islanding operations 2 Note A triggering event is not necessary if the completion of the prior step leads to the transition of the following step. Fault Response Island Operation V1.2.doc 17 January 14, 2010

18 Info 2.2 RAS Continuous Calculations of Balanced Segments from load shedding/curr ent limiting RAS continually calculates a series of achievable balanced scenarios with load shedding/current limiting based on possible segment schemes RAS RAS Calculations of Balanced Segments from load shedding/current limiting Possible segmentation schemes are limited by the availability of phase angle matching switching gear 3 Availability Monitor Rates according to SAIDI, SAIFI and critical loads Availability Monitor rates scenarios by SAIDI, SAIFI impacts, with consideration of critical loads Availability Monitor Availability Monitor Scenario Ratings according to SAIDI, SAIFI and critical loads 4.1 Network Determining breakers Network determines Equipment which should be tripped in event of emergency to create balanced island areas Network Network Emergency Equipment Commands for 4.2 Network Additional s Network determines additional system operations that will need to be performed to balance island areas Network Network Additional s for Balanced Operation for scenario Fault Response Island Operation V1.2.doc 18 January 14, 2010

19 Info 5 Create Creates appropriate profiles for Bay Controllers and dependent IEDs as required and pushes them to affected Bay Controllers and dependent IEDs as required Bay Controllers and IEDs Appropriate Includes load shedding and AMI Current Limiting 6.1 WOMS Schedule Maintenance WOMS system schedules maintenance WOMS WOMS Scheduling of maintenance work order 6.2 WOMS Sends affected segments 6.3 RAS Islanding Scenario Accepted WOMS sends affected segments and time frame (minutes ahead) to DMS/OMS/SCADA determines the appropriate RAS Islanding Scheme based on maximizing system indices with full load shedding. WOMS DMS/OMS/S CADA Maintenance Order Affected Segment and timeframe RAS Islanding Scenario Orders Altered protection settings appropriate to island operation, as well as adjusted ranges appropriate to island operation selects appropriate RAS scheme based on maximizing system indices with full load shedding. Fault Response Island Operation V1.2.doc 19 January 14, 2010

20 Info AMI Subsystem Sends AMI Commands generates Load Shed, current limit orders and passes them to AMI AMI Subsystem sends commands to the AMI Endpoints AMI Subsystem AMI Subsystems AMI Endpoints Load Shed/Current Limiting Orders Load Shed/Current Limiting Orders generates Load Shed, current limit orders and passes them to AMI 7.1 Charge Schedule generates storage charge/discharge orders based on new generation and loading profile Optimized Charge/Discharg e Schedule for DER Storage Units 7.2 Schedule calculates Optimized Schedule based on new generation and loading profile Optimized DER Device Schedule 7.3 regulation Profile generates voltage regulation profiles based on new generation and loading profile Optimal Fault Response Island Operation V1.2.doc 20 January 14, 2010

21 Info 7.4 Setting calculates Optimal Setting for the day based on new generation and loading profile Optimal Setting 7.5 Charge/Disch arge Schedule Push pushes Optimized Charge/Discharge Schedule for DER Storage Units to DER Device (storage units). Storage Unit Optimized Charge/Discharg e Commands/Sche dule for DER Storage Units Storage Units Storage Responds Accordingly The DER Units Respond Accordingly Storage Unit Storage Unit Optimized Charge/Discharg e Commands/Sche dule for DER Storage Units 7.6 Schedule Push pushes Optimized Schedule to (generation units). Unit Optimized DER Device Commands/Sche dule Units Responds Accordingly The DER Units Respond Accordingly Unit Unit Optimized DER Device Commands/Sche dule Fault Response Island Operation V1.2.doc 21 January 14, 2010

22 Info 7.7 Profile Push pushes Optimal to the as appropriate Optimal Responds Accordingly The Respond Accordingly Optimal 7.8 Setting Profile Push pushes Optimal Setting to the as appropriate Optimal Setting Responds Accordingly The Responds Accordingly Optimal Setting 8 Power Flow Monitoring Power Flow Reports Power Flow Monitoring function reports balance and flows Power Flow Monitoring Power Flow Monitoring Power Flow of Line Segments 9 Ready for island operation signals OMS ready for island operation OMS Ready for island operation Fault Response Island Operation V1.2.doc 22 January 14, 2010

23 Info 10 SCADA Trips Equipment 11 Normal Operation OMS Trips Equipment via SCADA continues operation with an embedded island OMS SCADA Equipment Commands Post-conditions and Significant Results Actor/Activity Electric Power Post-conditions Description and Results Operating within normal ranges with one or more de energized segments, and one or more islanded segments within the distribution grid. 2.3 Architectural Issues in Interactions Elaborate on all architectural issues in each of the steps outlined in each of the sequences above. Reference the Step by number. Double click on the embedded excel file record the changes and save the excel file (this updates the embedded attachment). 2.4 Diagram For clarification, draw (by hand, by Power Point, by UML diagram) the interactions, identifying the Steps where possible. Fault Response Island Operation V1.2.doc 23 January 14, 2010

24 5.2.1 AMI Centralized AMI Units s SubStation (Location 1) DER Controller Fault Response Island Operation V1.2.doc 24 January 14, 2010

25 3 Auxiliary Issues 3.1 References and contacts Documents and individuals or organizations used as background to the function described; other functions referenced by this function, or acting as sub functions; or other documentation that clarifies the requirements or activities described. All prior work (intellectual property of the company or individual) or proprietary (non-publicly available) work must be so noted. ID Title or contact Reference or contact information [1] 3.2 Action Item List As the function is developed, identify issues that still need clarification, resolution, or other notice taken of them. This can act as an Action Item list. ID Description Status [1] 3.3 Revision History For reference and tracking purposes, indicate who worked on describing this function, and what aspect they undertook. No Date Author Description /26/2009 Charles Vincent Original Fault Response Use Case 1.2 1/14/2010 Brian D. Green Update Actors, Steps and Diagram Fault Response Island Operation V1.2.doc 25 January 14, 2010