Validation of Generation Meter Data in MV-90 xi

Transcription

1 Validation of Generation Meter Data in MV-90 xi Patrick Vinton Supervisor, Meter Data Acquisition & Renewable Energy Credit Trading Programs Itron Utility Week October, 2013

2 AGENDA ERCOT Overview Metering in the ERCOT Market EPS Meter Data Collection Validation Requirements Meter Events Important? Specific Validation Examples Results of Validation Checks Reference Information Questions? 2

3 ERCOT Overview 3

4 ERCOT Timeline History of the Electric Reliability Council of Texas (ERCOT) 1941 Utilities band together to aid war effort 1970 Texas Interconnected System (TIS) forms ERCOT to comply with North American Electric Reliability (NERC) requirements 1981 ERCOT assumes central operating coordinator role 1995 Texas legislature votes to deregulate wholesale generation 1996 ERCOT becomes first Independent System Operator (ISO) in US 1999 Legislature votes to deregulate retail electric market 2001 Ten control centers merged into one control center 2002 Retail electric market opens, enabling customer choice for 6.1 million 2010 ERCOT implements Nodal Markets 2012 ERCOT has about 600 employees and an annual budget of about $170 million 4

5 ERCOT Quick Facts Market size: about $34 billion All generation data is collected and processed using MV-90 xi ERCOT covers 75% of Texas land ERCOT handles 85% of Texas load (23 million consumers) More than 40,500 miles of transmission lines 550+ generation units (more than 74,000 MWs of capacity) Peak Demand in ERCOT was set on August 3, 2011 at 68,305 MWs Physical assets are owned by transmission providers and generators, including Municipal Utilities and Cooperatives 5

6 ERCOT Quick Facts Responsibilities: The Texas Legislature restructured the Texas electric market in 1999 by unbundling the investor-owned utilities and creating retail customer choice in those areas, and assigned ERCOT four primary responsibilities: System reliability planning and operations Open access to transmission Retail switching process for customer choice Wholesale market settlement for electricity production and delivery. 6

7 The Texas Competitive Model Generation T&D ( Wires ) Retailers End Users REP REP Competitive Production Regulated Open Access Competitive Sales 7

8 ERCOT is one of 10 North American ISOs/RTOs ISOs/RTOs serve 67% of U.S. population with the goal of providing: Reliability Efficiency Transparency Impartiality ERCOT connections to other grids are limited to direct current (DC) ties, which allow control over flow of electricity. 8

9 ERCOT Footprint 9

10 Metering in the ERCOT Market 10

11 Meter Types ERCOT Polled Settlement (EPS) Meter Generation metering points Transmission Connected Distribution Connected (optional) Non-Opt-in-Entity (NOIE) metering points Bi-directional Radial point (optional) TDSP Metered & Read Distribution Connected Generation (can be EPS) Radial NOIE Metering point (can be EPS) Competitive Loads 11

12 EPS Meters TDSP Approves Meter Type, as long as it conforms with; ERCOT Protocols Applicable ANSI Standards Settlement Metering Operating Guide (SMOG) Back-up Meters Required (with a couple minor exceptions) Same or different manufacturer/type/model 12

13 EPS Meter Data Collection 13

14 EPS Meter Data Collection 1250 meters with 19 Different Utilities Austin Energy AEP-Central AEP-West Texas Brazos Electric Big Country Co-op Bryan Texas Utilities College Station Utilities City Public Service San Antonio Denton Municipal Electric Garland Electric Greenville Electric Utility System Lower Colorado River Authority Brownsville Public Utilities CenterPoint Energy Sharyland Electric South Texas Electric Co-op Texas Municipal Power Authority Texas-New Mexico Power Co Oncor 14

15 EPS Meter Data Collection continued Performed DAILY by ERCOT 7 days a week (yes, weekends AND holidays!) Validation, Editing and Estimation (VEE) ERCOT Protocols Settlement Metering Operating Guide Uniform Business Practices (UBP) 19 TDSP s must assist ERCOT in repairing metering issues and correcting missing or bad data 15

16 Validation Requirements 16

17 Validation, Editing & Estimation (VEE) Why do Extensive Validation of your Meter Data? 17

18 Validation, Editing & Estimation (VEE) Per ERCOT Protocols Section , the validation process will include, but not be limited to, the following tests: Flagging of intervals with missing data; Exception reporting if the total number of zero values for any channel exceeds the tolerance limit; Exception reporting if the total number of power outage intervals exceeds the tolerance limit; Channel level exception reporting if any single interval breaches the upper or lower threshold of the limit; Channel level validation of the percent change between two consecutive intervals being greater than the established tolerance limit; 18

19 Validation, Editing & Estimation (VEE) continued Per ERCOT Protocols Section , the validation process will include, but not be limited to, the following tests: Data overlap validation test, which rejects validations when the current interrogation of data overlaps data previously collected; Channel level energy tolerance test, which reports exceptions of total energy accumulated from the interval data not being equivalent to the energy calculated from the meter register s start and stop readings; Validation that the number of expected intervals equals the number of actual intervals collected during the interrogation process; and Validation of data between primary, backup and check meters where available. 19

20 Validation, Editing & Estimation (VEE) continued What check in MV-90 xi is this? Flagging of intervals with missing data; Missing data Exception reporting if the total number of zero values for any channel exceeds the tolerance limit; Zero Interval Tolerance Exception reporting if the total number of power outage intervals exceeds the tolerance limit; Power Outage Interval Tolerance Channel level exception reporting if any single interval breaches the upper or lower threshold of the limit; High/Low Limit (Demand) Channel level validation of the percent change between two consecutive intervals being greater than the established tolerance limit; Interval Percent (%) Change 20

21 Validation, Editing & Estimation (VEE) continued What check in MV-90 xi is this? Data overlap validation test, which rejects validations when the current interrogation of data overlaps data previously collected; Data overlap Channel level energy tolerance test, which reports exceptions of total energy accumulated from the interval data not being equivalent to the energy calculated from the meter register s start and stop readings; Usage/Energy Tolerance Validation that the number of expected intervals equals the number of actual intervals collected during the interrogation process; Interval Tolerance Validation of data between primary, backup and check meters where available. Redundant Channel Tolerance 21

22 Meter Events 22

23 Events in Support of Validating Data The following events are also reviewed by the MV-90 xi Operator; AC Power Down AC Power Up Power Outage (Pulse Status Report) Lapse in Data (Pulse Status Report) Battery Failure Start of Test Mode End of Test Mode RAM Buffer Overflow Watchdog Timer Error/Reset Time Tolerances Phase Drop-out Phase Failure Phase Angle Limit Phase Restoration Potential A Inactive Potential B Inactive Potential C Inactive D80 Interval Errors (fatal errors on ION meters) 23

24 Specific Validation Examples 24

25 Zero Interval Tolerance Used to Detect the following; When the number of intervals containing a value of zero exceeds a defined number Base Load units generally should not have any zero intervals Non-Base Load units can have zero values and the tolerance value will be unit specific 25

26 Zero Interval Tolerance continued GOOD for; Base Load Units Nuclear Plants Coal Plants Any unit with an excepted steady energy curve NOT GOOD for; Peaker Units Pumping/Switching Units Weather Sensitive Units (wind, solar, etc) Defined in Channel Master File 26

27 Zero Interval Tolerance continued Which meter is a good candidate for this check? 27

28 High/Low Limit (Demand) Monitors an Interval s Maximum and Minimum value Ensures equipment in metering circuit is not being overloaded or exceeding circuit s design capacity Catches erroneous spikes/dips in data Identify energy flow on a line that should not have energy flow Defined in Channel Master File 28

29 High/Low Limit (Demand) continued Interval Max: Max Capacity of Metering Point +10% Interval Min: Depends on unit type, i.e., Base Load units may be set to fail if the interval value drops below 75% of previous 3 years average value. Non-Base Load Units may not use this check. 29

30 High/Low Limit (Demand) continued Interval Max: Max Capacity of Metering Point +10%, i.e., 850MW Unit = 935MW (850+85=935) 30

31 High/Low Limit (Demand) continued Interval Min: Depends on unit type, i.e., Base Load units may be set to fail if the interval value drops below 75% of previous 3 years average value. Is unit specific Non-Base Load Units may not use this check if the unit regularly drops to zero For this unit, anything below 1200MW is set to fail validation 31

32 Interval Percent (%) Change Used to Detect the following; Ramp rate exceeds specifications Nuclear & Coal Plants generally have slower ramp rates than Gas or Weather-Sensitive Units Loss of Phase (LOP) or Transformer Balanced circuits would see a 33% drop Setting this tolerance to 25% would catch a LOP or a loss of a Current Transformer 32

33 Interval Percent (%) Change continued GOOD for; Base Load Units Nuclear Plants Coal Plants Any Relatively Steady Energy Curve NOT GOOD for; Peaker Units Pumping/Switching Units Weather Sensitive Units (wind, solar, etc) Defined in Channel Master File 33

34 Interval Percent (%) Change continued Which meter is a good candidate for this check? 34

35 Redundant Channel Tolerance Compares, on an Interval-by-Interval basis, the KW (demand) values between a PRIMARY meter and the designated BACKUP meter that shares the same electrical connection Ensures a backup data source where data is deemed financially critical, such as; Grid-Level Monitoring Generators Inter-Tie Points Helps identify meter problems at critical points in the Utility Grid 35

36 Redundant Channel Tolerance - continued There are two (2) options in MV-90 xi Absolute Difference Channel Tolerance % 36

37 Redundant Channel Tolerance - continued Absolute Difference Option ERCOT uses this option when comparing interval data between 2 meters Absolute Difference is in KW This is the Absolute Difference the 2 meters can differ on an interval-by-interval basis and still pass Validation Defined in Channel Master File 37

38 Redundant Channel Tolerance - continued 38

39 Redundant Channel Tolerance - continued Factors ERCOT uses to determine Absolute Difference value: Meter Point Capacity Meter Uncertainties Allowable Time Drift between meters Transformer Uncertainties (PT s and CT s) Meter Point Capacity x (meter uncertainties + allowable time drift between meters + PT uncertainty + CT uncertainty) PT and CT uncertainties can be ignored if BOTH meters share the same transformers as any error will effect both meters in the same direction 39

40 Redundant Channel Tolerance - continued Example: Meter Point Capacity = 850 MW Meter Uncertainties = 0.15% (per meter) Allowable Time Drift = 1% of Interval Length (9 seconds per meter) Transformer Uncertainties = N/A as they are shared 850 x (0.3% + 2% + N/A) = 850 x 2.3% = MW (19,550 KW) For this meter point, the meters can differ up to 19.55MW and meet all accuracy requirements As MV-90 xi is in KW, the value entered in the channel master file would be

41 Redundant Channel Tolerance - continued For this meter point, the meters can differ up to 19.55MW and meet all accuracy requirements But the actual difference is 24.1MW, thereby failing the redundant validation check 41

42 Redundant Channel Tolerance - continued Channel Tolerance % Option This option is used when comparing channels within the SAME meter to identify issues such as a loss of a current transformer, i.e., If current channels are programmed in meter channels 5-7, compare Chan 5 to Chan 6, Chan 6 to Chan 7 Using 25% would catch a loss of a current transformer or a meter issue Defined in Channel Master File 42

43 Redundant Channel Tolerance (Helpful Hints) The Channel Tolerance % method does not work well on pulse meters when the pulses per interval are low Example: tolerance set to +/-5%. If one meter has 10 pulses and another meter has 9 pulses, there is a 10% difference and the validation check fails IF Possible, use the same meter type for the Backup meter and program it the SAME as the Primary meter Editing: do not have to scale data because of different multipliers when editing/copying from one to the other Set Call Time in Backup Meter s Master File to dial BEFORE the Primary Meter If Primary dials first, the Redundant Check will fail as there is no Backup meter data to compare to. 43

44 Results of Validation Checks EPS Meter Data is the Baseline data in which the ERCOT Market settles All Load Data is matched to Generation Data Key Performance Indicator (KPI) requirement is that >99.5% of EPS Meter Data remain unchanged after the settlement process occurs Tracked by Quarter and YTD 2012 Year-End % For 2013; 1 St Qtr % 2 nd Qtr % 3 rd Qtr % YTD % 44

45 Reference Information EPS Metering Protocols Section 10 & 11 Settlement Metering Operating Guide (SMOG) Metering Documentation/Forms 45

46 QUESTIONS? 46