Copyright © PGE, Advanced Energy Industries, and SEL 2014 Field Testing of 3G Cellular and Wireless Serial Radio Communications for Smart Grid Applications Robert Ferraro and Chris Steeprow Portland General Electric Michael Mills-Price Advanced Energy Industries, Inc. Bill Flerchinger and JW Knapek Schweitzer Engineering Laboratories, Inc.

Agenda Wireless communications in power delivery applications SEGIS-AC project test site and system configuration Evaluation of wireless performance using synchrophasor data ♦ Serial radios ♦ Cellular modems Findings and conclusion

Communications Are Critical for Smart Grid Applications

Why Use Wireless? Right-of-way issues Installation cost Deployment time

Wireless Communications Choices

Typical Utility Application Requirements ApplicationLatencyBandwidthDistanceAvailability Teleprotection4 to 60 msLow~20 milesHigh Distributed generation island detection 20 ms to < 2 s Low to medium ~10 milesHigh High-speed restoration ~50 to 100 ms Low~10 milesHigh

Typical Utility Application Requirements ApplicationLatencyBandwidthDistanceAvailability SCADA communications SecondsMediumVaries Medium to high Voltage control Seconds to minutes Low~10 milesMedium Remote accessSecondsMedium~10 miles Low to medium Meter reading Minutes to hours LowVariesLow

Advanced Energy SEGIS-AC Project Island detection for high-penetration PV installations Ramp rate controller Feeder-level optimization

Why Use Synchrophasor Data? PMU Data Play Critical Role in Project Provide live response curve for feeder ♦ High resolution ♦ Near real-time measurements Optimize solar and storage system output Provide time-synchronized, accurate measurements across feeder

IEEE C Summary Is standard for synchrophasors for power systems Provides measurements for frequency, df/dt, voltage and current phasors, analog values, and digital status words Has message rates from 1 to 60 per second Time-synchronizes all measurements to 1 μs

Test Site Canby-Butteville Feeder

System One-Line Diagram

Baldock PV Site

Baldock PV Site Equipment GPS Clock PMU 5 PDC Cellular Modems Switch Serial Radios Automation Controller Router

Redundant Communications Comparison Parameters Serial RadioCellular Modem Target application Teleprotection and distribution automation Machine-to-machine communications Frequency band 902–928 MHz (ISM band) 800 / 1900 MHz (dual-band) Wireless technology FM (GFSK) frequency hopping 3G 1xEV DO Rev A CDMA and TDM 16QAM

Redundant Communications Comparison Parameters Serial RadioCellular Modem Peak data rate 38.4 kbps (Serial Port 1), 19.2 kbps (Serial Port 3) 3.1 / 1.8 Mbps (downlink/uplink) InterfacesSerialSerial, Ethernet Equipment cost$1,500 per device$750 per device Monthly costNA$59 per device

Wireless Device Interconnections

Making Wireless Operational Path study Site survey Temporary test system Spectrum analysis Future site plans

Path Study Pole 4 to Baldock PV Site

Optimizing Serial Radio Performance Antenna polarization Frequency skip zones TX / RX synchronization

Cellular Coverage Closest Cellular TowerBaldock PV Site

Modem Setup

Lessons Learned Setting Up Wireless Training is required Involve IT organization Plan up front – path study, site survey, and so on Actual performance of system may vary

Wireless Performance Summary Communications Link RSSI Reported at Baldock PV Site (dBm) Total Measured Latency (ms) (wireless only) Calculated Availability (%) Wired (Serial)NA112 (NA)100 Wired (Ethernet)NA109 (NA)100 Serial Radios 1 to 5–80168 (56)100 Serial Radios 2 to 6–77167 (55)100 Serial Radios 3 to 7–65169 (57)100 Serial Radios 4 to 8–51167 (55)100 Cellular Modems 1 to 5–64334 (225)99.60 Cellular Modems 2 to 6–64351 (242)99.78 Cellular Modems 3 to 7–96353 (244)99.24 Cellular Modems 4 to 8–68353 (244)98.30

Wireless Latency and Availability Dropouts Serial Radios Cellular Modems Wired Serial Radios Cellular Modems

Availability – One Day at a Time Serial Radios Cellular Modems

Recommended Applications Serial radios ♦ High-availability protection or control ♦ Applications requiring low latency ♦ Remote or populated areas 3G cellular modems ♦ High-bandwidth data transfers ♦ Applications tolerant of dropouts ♦ Only areas with cellular coverage

Conclusion Wireless communications can be used in smart grid implementations Up-front studies and planning are needed to ensure smooth rollout and robust connection Many wireless solutions are available – choose to match requirements 3G cellular may not be well suited for synchrophasor applications

Questions?