1. Academic Experience with Wide Area Sensors by Virgilio Centeno Virginia Tech PSC, Distributed Generation, Advanced Metering and Communications March 9, 2005 Clemson University

2. Historic Development of PMU at Virginia Tech 1982 - 1986 Conceptual Development 1986 - 1988 Implementation 1988 – 1990Tests on Experimental Units 1989 - 1991 Transfer Technology to Industry 1992 – now Diverse Applications Model Validation Out-of Step Relaying Unit Placement State Estimation Visualization Oscillation Detection Unit Testing Error Assessment 1999 – now Wide Area frequency Measurement

3. 1982 – 1986 Initial Concepts Expansion of algorithm derived for distance protection For computer based relays. x i x r  

4. E 1  1 2 E  2  2  1 - 2 E E 1 2 E E 1 2 E E 1 Time as a Reference

5. GPS Receiver: - 1Second Pulse (±100 nS) - Time Tag Time Synchronization with GPS GPS Clock: - Sampling Pulse - Accuracy reduced to 1  s ( 0.022° ) 1986 GPS not fully developed and under military control

6. Virginia Tech Experimental PMU First Commercial PMU (1989-1991) Technology Transfer to Industry

7. 1992: First Wide Area Measurement with PMUs Duke Power TVA Alabama Power Hatch Thalmann Duval Vogtle Martin Generation Substation 1992 Measurements used for Model Validation

8. Georgia Florida Out of step condition S-PMU Relay S-PMU Relay Main Problem: Communication Errors 9600 Baud Modem 4 wire leased telephone line 1993-1994 Applications: Out-Of-Step Relaying

9. Linear state estimator Enhanced State Estimation State Measurement 1990 – Present: State Estimation Applications Algorithms for PMU Placement for Obserbability

10. 1993- Present Dynamic Applications Unit Placement Detection of System Oscillations

11. Defines the interface between the GPS receiver and PMU Defines the data format of phasors being transmitted first transmitted SOC SMPCNT STAT Phasor #1 Phasor #2 Phasor #n FREQ DFREQ DIG #1 DIG #K CRC last transmitted... 16 4 2 2 22 2 22 4 44 MSBLSB DATA FORMAT IEEE standard 1344-1995 SYNCHROPHASOR 1993 – present Standardization Efforts

12. (March 2003) PMU Testing

13. Single Phase Voltage at off-nominal Frequencies Angle vs Frequency 30 50 70 90 110 130 150 170 190 5556575859606162636465 Frequency (Hz) Angle Degrees Unit A Unit B Unit C Unit D

14. 1992 – Present Wide Area Data Visualization

15. 1995 – Present: New Devices and Concepts 89.0 90.091.0 92.0 93.0 94.0 95.096.0 97.0 Seconds -0.2 -0.1 0.0 Hertz Comanche Peak Nuclear Station Full Load Rejection Test Jewett Min. -0.2186 Hz Odessa Min. -0.2456 Hz Venus Min. -0.2262 Hz Robinson Min. -0.2344 Hz     (deviation from 60Hz) Continuum Model for Power Systems Frequency Monitoring Network (FNET)

16. GPS Receiver A/D Converter ProcessorNIC Low Pass Filter Analog Signal Analog Signal Output Pulse Synch Time Network Card FNET - Frequency Recording Unit (FRU) Design FNET - Frequency Recording Unit (FRU) Design Measurements from any Single Phase 120Volt outlet 1999- Present: Frequency Wide Area Measurement

17. GPS/Internet Based Frequency Monitoring Network (FNET) Gateway Server WAN TCP/IP LAN Data Warehouse MMI Router Firewall Router Firewall WAN FRU 1 FRU n Internet User FRU 2 FRU n Internet User