Survey and Summary of Best Practices for Distribution Reliability Improvement. December 8, p.m. EST

Transcription

1 Survey and Summary of Best Practices for Distribution Reliability Improvement December 8, p.m. EST

2 Webinar Overview Moderator: Speaker: Michele Suddleson DEED Program Director American Public Power Association Dr. Suresh Gautam Senior Engineer, Power System Operations & Planning GE Energy Consulting

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4 What is DSTAR? DISTRIBUTION SYSTEMS TESTING, APPLICATION, AND RESEARCH DSTAR is a consortium of utilities organized to cooperatively sponsor practical and cutting edge distribution systems research and development. 4

5 DSTAR Program 14 Members Ameren Corporation APPA/DEED Duke Energy NRECA/CRN South Carolina E&G Southern Company PacifiCorp 5

6 Project Objectives Primary objective: o To assemble information that will help utilities utilize commonly collected reliability data to improve overall system reliability. Tasks: o Literature Review Conduct literature review on industry practices for distribution system reliability improvement. o Member Survey Conduct a survey among DSTAR members, o Document and Summarize the findings. 6

7 Member Survey Web-based hosted by APPA Number of questions (max) - 27 Survey period Fall 2014 Total participants - 54 All participants were DSTAR members 7

8 Reliability Indices

9 Reliability Indices Reliability is characterized by the ability of the system to deliver power to the end-customer. Key measures o Frequency of outages (how often they occur) o Duration of outages (how long they last) Swells Sags Sustained Interruption Frequency Noise Power Quality Reliability Availability Interruption Duration Transients Momentary Interruption Frequency Frequency Variation Flicker Harmonic Distortion Power Quality problem is deviation from a perfect sinusoidal voltage source 9

10 Reliability Indices Reliability Indices defined by IEEE Standard o Customer-based SAIFI, SAIDI, CAIDI, ASAI, CAIFI, CTAIDI, MAIFI, MAIFIe, CEMIn, CEMSMIn o Load-based ASIFI, ASIDI Other L-Bar, ACIDI, ACIFI o Power quality-based SARFIx, SIARFIx, SMARFIx, STARFIx Common Indices: SAIFI, SAIDI, CAIDI, ASAI and MAIFI 10

11 Reliability Indices System Average Interruption Frequency Index Number of Customer Interruptions SAIFI Total Number of Customers Served /yr System Average Interruption Duration Customer Interruption Durations SAIDI Total Number of Customers Served hr/yr Customer Average Interruption Duration Index CAIDI Customer Interruption Durations Number of Customer Interruptions SAIDI SAIFI hr Momentary Average Interruption Frequency Index Number of Customer Momentary Interruptions MAIFI Total Number of Customers Served /yr 11

12 Reliability Indices Industry Usage R. E. Brown, Electric Power Distribution Reliability, 2009 Marcel Dekker 12

13 Reliability Indices DSTAR Members 13

14 Reliability Indices Usage of Reliability Indices hasn t change much in more than a decade 14

15 Reliability Targets and Reporting

16 Reliability Targets Reliability targets are typically set internally or by state regulators If set by regulators they may come with reward/penalty structure Targets o Define goals for engineering and operations o Drive capital and O&M spending on improvement projects and additional resources Four methods of setting targets: o Arbitrary management chooses targets o Survey customer survey of preferences o Historical comparison to previous years o Value-based analysis of total societal impact 16

17 Reliability Targets DSTAR Members 17

18 Reliability Reporting DSTAR Members 18

19 Reliability Reporting and Targets Setting target based on single reliability index is fairly straightforward Spending decision can be made based on benefit-cost analysis However, o Utilities track multiple indices for multiple goals o Targets has to be set based on multiple indices The spending decision should be based on optimal spending determined by a multi-objective multi-constraint optimization problem For example: if a project is chosen based on SAIFI improvement, it will also improve SAIDI but it does not address the customer-cost associated with the duration of outage (SAIDI) Area/district/feeder level targets are more effective compared to system level targets 19

20 Interruption and Restoration

21 233 minutes Interruption and Restoration Detection of Interruption o Manual: Customer call/ivr (Off hour vs. Normal hour) o Automatic: OMS, DMS, SCADA, AMI or their Combination(s) Location of fault/failure o Manual: Crew Patrol, Visual Fault Indicators, o Automatic: OMS, DMS, SCADA, AMI, FCI or their Combination(s) Pre-repair restoration (Network reconfiguration) o Manual o Automatic o Two stage (Automatic followed by manual) Repair Post-repair restoration (Service restoration) Trouble call Trouble analysis & dispatching Confirmation Travel Repair Repair time is the biggest contributor to the total duration of interruption 21

22 Detection of Interruption DSTAR Members 22

23 Location of Fault/Failure DSTAR Members 23

24 Pre-repair Restoration DSTAR Members Reconfiguration scheme to restore customers prior to repair 24

25 Repair and Service Restoration DSTAR Members 25

26 Interruption and Restoration Minimize the impact o Fuse saving vs. fuse clearing o Reclosers Automation o Automatic outage/interruption detection o Automatic network reconfiguration Reconfiguration scheme (addition of sectionalization switches and normally open ties) Two stage restoration Work management system Impact minimization: minimize the affected area Faster restoration: minimize detection, isolation and repair time 26

27 Data Collection and Post-Event Analysis

28 Data Collection All utilities collect data during outage for post-event analysis or for reliability reporting, Wide variation in process for outage reporting and data collection, Some of the data collected during outages include, o Start time o Affected circuit, configuration, topology, voltage etc. o Failed equipment/device and interrupting device o Cause of interruption o Affected customer and type o Pre-repair restoration steps and time (including two step restoration) o Response time and crew dispatch o Repair time o Final restoration time o Verification of restoration 28

29 Data Collection DSTAR members 29

30 Data Collection DSTAR members 30

31 Post-Event Analysis DSTAR Members 31

32 Data Collection and Post-Event Analysis Prioritize data collection and post-event analysis Adequate and accurate data collection is the key Provide a dedicated reliability engineer, (optimizing the number depending on the size and operating area of utility) Reliability indices for each operating area/district/substation Perform root cause analysis for selected events Identify area susceptible to frequent interruptions Optimal number of crew and their strategic location A good data collection facilitates meaningful post-event analysis and helps set reliability targets/goals 32

33 Reliability Improvement

34 Improving Distribution System Reliability Effective reliability improvement strategies are best implemented as part of a distribution plan that o Incorporates relevant goals and criteria o Performs thorough system analysis o Considers cost and historical performance Two main paths to improve system reliability o Design: focus on system topology, connectivity and switching possibilities o Operation: focus on aspects of equipment maintenance, inspection and repair 34

35 Improving Distribution System Reliability System configuration o Reduce exposure on feeder layout o Relocate or create more normally open (tie) points o Reconductor, add new feeders or substations o Looped or networked vs. radial o Underground vs. overhead 35

36 Improving Distribution System Reliability Sectionalizing switches o Improve reliability by allowing faults to be isolated and customer service to be restored while fault is repaired Automation o Monitoring and control equipment to allow for faster switching, fault location and restoration o Automating a few key switches gives great benefit, but there is diminishing marginal returns o Greater impact on SAIDI than SAIFI 36

37 Improving Reliability DSTAR Members Top five techniques and strategies that your company uses to reduce duration of customer interruptions (improve SAIDI) 37

38 Improving Distribution System Reliability Improving response time o Emphasis is on SAIDI index Feeder automation Outage management systems (OMS) Automatic fault location devices (FCI, DMS, OMS, ADMS) Multistage restoration prior to completing repair (if possible) Increased number of crews and dispatch centers Work management systems and automated crew dispatch Effective crew training Speed up restoration and service times after a fault has occurred 38

39 Improving Reliability DSTAR Members Top five techniques and strategies that your company uses to prevent customer interruptions (improve SAIFI) 39

40 Improving Distribution System Reliability Reducing equipment failures o Emphasis is on SAIFI index Increased inspection and monitoring Tree trimming and danger tree programs Marking/labeling, call before digging programs Use of covered (tree) wire or spacer cable Infrared inspection programs Cable replacement programs Wildlife protection programs Lightning protection (arresters, shield wire, effective grounding) Transformer load management (TLM) programs Proactive maintenance strategies (TBM, CBM, RCM) Most effective (preventive) approach to improve reliability 40

41 Reliability Improvement Plans DSTAR Members 41

42 Improving Distribution System Reliability Other approaches, o Reliability reporting (internal) o Reliability culture, incentive plan with accountability o Target worst performing circuit o Target worst served customers o Prepare for extreme weather conditions o Cost of reliability and willingness to pay studies o Evaluation of impact of reliability improvement programs Efficient and effective planning is the key 42

43 Potential Impact DSTAR Members Technologies, strategies or policies that have the potential to impact system reliability Survey Response: Distributed Generation/Distributed Energy Resources Self-Healing Networks Communication Devices/Equipment Distribution Automation, ADMS, AMI Faulted Circuit Indicators / Fault Indicators Net Metering EPA Emission Policies Microgrids Be prepared for change and changing operating environment 43

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45 DSTAR Section on DEED Site The DSTAR page contains summaries and reports on current and completed DSTAR projects since 2010 Go to and choose the DSTAR tab. Log in with your APPA username and password

46 DEED Member Opportunities Spring grant cycle is open. Apply for up to $125,000 in funding for innovative projects Gain recognition: Nominations open for the Award of Continued Excellence or Energy Innovator Award Deadline: January 31, 2017 New user? Questions? Contact

47 Upcoming Webinars DSTAR Webinar: LED Street Lighting Analysis. January 10, 2 3pm EST Overcoming Customer Barriers to Increase Participation and Savings in Audit Programs. January 17, 2 3:30pm EST

48 DEED Contact Information Michele Suddleson DEED Program Director Richelle Dodds DEED Program Coordinator

49 Thank you for joining us for today s webinar!