21st Century Power Measurements
- 1. 21st Century Power Measurements Prepared by Bill Hardy, TESCO The Eastern Specialty Company For North Carolina Electric Meter School Management Session Wednesday, June 27, 2018 at 1:45 p.m.
- 2. Then – Now – Tomorrow? Meters First Meters mid-1890s Westinghouse 1905 2005 2006 2014 2025 ??? 2
- 3. Then – Now – Tomorrow? Meters?? 3
- 4. Then – Now – Tomorrow? Loads YESTERDAY TODAY 4
- 5. Then – Now – Tomorrow? Loads TODAY 5
- 6. Then – Now – Tomorrow? Communications THEN NOW 6
- 7. Why do these changes matter? • Changes to our loads have changed the basic computations of metering. • When loads were linear the power triangle was all we needed to know 7
- 8. Why do these changes matter? • Today’s loads look more like these -150 -100 -50 0 50 100 150 0.00 60.00 120.00 180.00 240.00 300.00 360.00 Voltage/Current Current for CCFL Light Bulb Voltage Current 8
- 9. Why do these changes matter? • Today’s loads look more like these -150 -100 -50 0 50 100 150 0 60 120 180 240 300 360 Voltage/Current Variable Speed Motor Voltage Current 9
- 10. Why do these changes matter? • Today’s loads look more like these -150 -100 -50 0 50 100 150 0.00 60.00 120.00 180.00 240.00 300.00 360.00 Voltage Current for Switching Power Supply Voltage Current 10
- 11. Standards Changes • New Revision of C12.20 just Published Polyphase meters tested using polyphase Recommended now, required 2020 Unbalanced load testing required Full harmonic testing required 0.1% Accuracy Class added Specific call out of Non-Blondel applications where C12.20 does not apply Detailed requirements and specs for test outputs added 11
- 12. Harmonic Load Waveforms ANSI C12.20 now addresses harmonic waveforms -400 -300 -200 -100 0 100 200 300 400 -150 -100 -50 0 50 100 150 0 90 180 270 360 -200 -150 -100 -50 0 50 100 150 200 -150 -100 -50 0 50 100 150 0 90 180 270 360 -8 -6 -4 -2 0 2 4 6 8 -200 -150 -100 -50 0 50 100 150 200 0 90 180 270 360 -150 -100 -50 0 50 100 150 0 60 120 180 240 300 360 -250 -200 -150 -100 -50 0 50 100 150 200 250 -150 -100 -50 0 50 100 150 0.00 100.00 200.00 300.00 -150 -100 -50 0 50 100 150 -150 -100 -50 0 50 100 150 0.00 100.00 200.00 300.00 Current Voltage 12
- 13. Standards Changes • New Revision of C12.20 just Released Tighter reference condition performance specifications When using polyphase loading meters must be tested in each configuration used 13
- 14. Standards Changes • New Revision of C12.1 0.5% Accuracy Class added Testing required for unbalanced loads Testing required under unbalanced conditions Tighter reference performance requirements Bi-directional energy flow testing Extensive update on in service testing 14
- 15. Standards Changes • New Revision of C12.10 in 2015 Accuracy tests moved here from C12.1 Much broader safety requirements Coordinated effort with UL2735 • Utilities exempt from UL2735 but only if they own and install the equipment 15
- 16. Standards Changes • New Revision of C12.9 in 2014 Full specifications for test plugs included in standard • Ensures safe operation between all switches and all plugs • previously some combinations produced safety hazards New barrier requirements between switch elements 16
- 17. Standards Changes • Communications Standards New C12.19 which replaces C12.18 and C12.19 is in ballot process • Major changes – major controversy has held up approval for two years • Standard will still not guarantee inter-operability 17
- 18. ANSI C12.31 • At the moment there is no non-sinusoidal definition for VA • New ANSI Standard coming very soon C12.31 Slide 18
- 19. New Definitions RMS Voltage Slide 19 Basic Definition Time Domain Frequency Domain Waveform
- 20. New Definitions RMS Current Slide 20 Basic Definition Time Domain Frequency Domain Waveform
- 21. New Definitions Active Power Slide 21 Basic Definition Time Domain Frequency Domain
- 22. New Definitions Apparent Power Slide 22 Basic Definition Time Domain Frequency Domain
- 23. Next Generation Standards • ANSI C12.46 New standard in development to replace C12.1 and C12.20 Structured like OIML IR-46 A true digital age standard Applies to ALL energy measurements • Watts, VA and VAR • Contains precise definitions for the quantities based on digitally sampled waveforms 23
- 24. Next Generation Standards • ANSI C12.46 Covers ALL waveform types • sinusoidal, harmonic, time varying Defines the meter as everything under the cover • If there is auxiliary functions in the meter they must be fully operational during accuracy testing • If a option is added to a meter, it must be tested with the option running to remain qualified 24
- 25. Next Generation Standards • ANSI C12.46 View of accuracy changes • Currently changes with respect to reference • New approach is absolute error Philosophy of C12.46 – When a meter is claimed to be of a specific accuracy class, for example , AC 0.2%, then it’s accuracy under all commonly occurring conditions should be within ±0.2% maximum error. 25
- 26. What does the Future Hold • Over the next FEW years metering may have a whole new meaning • Do these look like meters to you? 26
- 27. What does the Future Hold • Each has an embedded revenue meter • They may NOT be regulated by the PSC’s. METER 27
- 28. Questions? Bill Hardy TESCO – The Eastern Specialty Company Bristol, PA 215-785-2338 This presentation can also be found under Meter Conferences and Schools on the TESCO web site: www.tescometering.com 28