Academic Experience with Wide Area Sensors

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 – 1990 Tests 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. x F i F x r 1982 – 1986 Initial Concepts Expansion of algorithm derived for distance protection For computer based relays.

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

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

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

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

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

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

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

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

12. (March 2003) PMU Testing

13. Single Phase Voltage at off-nominal Frequencies Angle vs Frequency 190 170 150 130 Unit A Unit B Angle Degrees 110 Unit C Unit D 90 70 50 30 55 56 57 58 59 60 61 62 63 64 65 Frequency (Hz)

14. 1992 – Present Wide Area Data Visualization

15. Comanche Peak Nuclear Station Full Load Rejection Test 0.0 Jewett Min. -0.2186 Hz  Odessa Min. -0.2456 Hz   Venus Min. -0.2262 Hz  Robinson Min. -0.2344 Hz -0.1 (deviation from 60Hz) Hertz -0.2 92.0 89.0 93.0 95.0 96.0 90.0 91.0 94.0 97.0 Seconds 1995 – Present: New Devices and Concepts Frequency Monitoring Network (FNET) Continuum Model for Power Systems

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

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