Eric Udren EPIC 2018

Synchrophasor Applications in Distribution

Synchrophasor measurements – Phasor Measurement Units (PMUs) with precision time source GPS receiver Analog Inputs

Phase‐locked oscillator

Anti‐aliasing filters

A/D conv

Comm. Port Phasor micro‐ processor

PMU

2 PM U Indirect

Phasor

Synchrophasor Applications in Distribution

US transmission PMU deployment

Source: US DOE 2016 “Advancement of Synchrophasor Technology” Report

Synchrophasor Applications in Distribution

Real‐time application of synchrophasors Time frame grid management using synchrophasor‐based Wide Area Monitoring, Protection, Automation and Control (WAMPAC)

Synchrophasor Applications in Distribution

Ecuadorian wide‐area system protection with synchrophasors The need: • Rapid generation expansion & demand growth led to stressed grid operations – certain double contingency (cross‐country) faults caused system collapse. The solution: • PMU‐based System Integrity Protection System (SIPS) or RAS – A fully redundant system deployed across 2 control centers, 12 monitoring and 11 mitigation substations; plus a training and development system. • Trips about 200 ms from triggering event. The process (completed < 3 years): • System studies to identify vulnerable operating states and fault events, and develop mitigation solutions. • Proceeded to system design and requirements specifications. • Deployed the SIPS through procurement, installation, testing and commissioning processes. The results: • In operation since January 2015. • Operated first time on May 6, 2015 – realized USD $1.1M economic savings. • Correctly operated three times to prevent national blackouts and economic loss. • Phase 2 expansion in progress. © Copyright 2018 Quanta Technology, LLC

Synchrophasor Applications in Distribution

What about WAMPAC applications in distribution? • The applications and benefits are completely different. • Early assumptions by some that we port transmission applications to distribution led to inappropriate solution attempts. • E.g. for state estimation we need to measure the voltage drop across a circuit section with the impedance of a mile of wire, leading to TVE accuracy specification of 0.01%.

• Seeing distribution device behavior and switching events require high‐speed measurements and data gathering, with conventional precision. • We also need:

Synchrophasor Applications in Distribution

Example applications of PMU systems in distribution • Wideband SCADA. • Monitoring customer loads, voltage deviations, power quality. • Monitoring distributed generation and storage resources. • Distributed and closed‐loop control. • Active/adaptive fault protection. • Apparatus monitoring. • High‐speed fault location, isolation, and restoration (FLISR). • Falling conductor detection (later).

Renewable Integration

Distribution Automation & Microgrids

Fire Hazard Prevention

Synchrophasor Applications in Distribution

Example applications of PMU systems in distribution • Over 60 use cases developed in a distribution PMU project at one utility.

Source: http://eetd.lbl.gov/news/article/58572/searching‐for‐real‐time‐measure

Synchrophasor Applications in Distribution

Distribution PMU requirements 1 User’s chosen PMU applications or use cases drive requirements Data rate ‐ PMUs measure time synchronized voltage,

current, and phase angle at frame rates of 1 to 240 values per second. • Modern transmission PMUs typically take 60 measurements per second. • General SCADA‐like but accurate distribution circuit measurements with phase angle – 1 per second. • Distribution voltage quality monitoring, current stability, control, and protection functions – 30 to 60 per second.

Synchrophasor Applications in Distribution

Distribution PMU requirements 2 Accuracy – Modern transmission PMUs have a 1% Total Vector Error (magnitude error with perfect phase, or ± 0.573 degree accuracy when magnitude error is 0). • Some users used to say: angle differences between PMUs are much smaller in distribution than in transmission because of lower X/R ratios and short line sections. • Modeling use cases theoretically require ± 0.01 degree accuracy or better ‐ takes $$$, and… • Instrument transformers aren’t that accurate; calibrating every location is impractical.

• Distribution use cases don’t require such precision modeling – they focus more on rapidly‐changing behavior of loads, generation, disturbances, and PQ. • Practical distribution voltage and current monitoring and protection functions work fine with 0.5% to 1% magnitude error, and 0.5 to 1 degree phase angle error.

Synchrophasor Applications in Distribution

Distribution PMU requirements 3 Synchrophasors and other information in data frames from the circuit: • Protection P class (and measurement M class) phasors measured per IEEE C37.118.1‐2011 or new IEEE/IEC 60255‐118‐1 Ed. 1, 2018. • Current demonstrations mostly done with IEEE C37.118‐2005 measurements.

• F, rate of change of frequency (ROCOF), P and Q, sequence voltages and currents as needed. • Compute some at system application level – unburden circuit IED & comms.

• Status and control points in phasor frames. • Wideband waveform data windows – not streamed synchrophasors: • Time‐tagged history, not real time ‐ too much information to stream. • Analyze in circuit IED or at substation/control center client for harmonics, flicker, distortion, transients, PQ indices. • Synchrophasor streams are filtered power‐frequency values only and exclude most other waveform information by nature! © Copyright 2018 Quanta Technology, LLC

Synchrophasor Applications in Distribution

Distribution PMU requirements 4 Communications interfaces and protocols • Serial or Ethernet port ‐ hardware interface(s) connect to communications channel equipment. • Synchrophasor stream protocols available – IEEE C37.118‐2005, C37.118.2‐2011, IEC TR 61850‐90‐5‐2011 Routable Sampled Values (R‐SV) (Ethernet only, WAN oriented, high security, future). • SCADA control protocol – DNP3 or Modbus exchange with DCC. • High‐speed status reporting and control protocol – IEC 61850 GOOSE (Layer 2 Ethernet) or IEC TR 61850‐90‐5‐2011 Routable GOOSE (R‐GOOSE) (Ethernet only, WAN oriented, high security, future). • Oscillographic and PQ records (COMTRADE, PQdif) – FTP, or vendor specific transport, with client software for viewing and analysis. • Event records and setting/configuration files – text or vendor specific transport with client software for viewing. © Copyright 2018 Quanta Technology, LLC Synchrophasor Applications in Distribution

Distribution PMU requirements 5 Time synchronization of PMU • IRIG‐B port for external GPS clock. • Embedded GPS receiver. • Future – IEEE 1588 Precision Time Protocol (PTP) over Ethernet communications with IEC 61850‐90‐3 and IEEE C37.238 power application profile. • PTP synchronized to remote master clocks, with local high‐precision backup clock option. Packaging and hardening for circuit equipment • Outdoor, pole‐top physical environmental requirements and enclosure. • Electrical and physical environmental requirements for circuit mounting – IEEE 1613/1613.1 and protective relaying standards. © Copyright 2018 Quanta Technology, LLC

Synchrophasor Applications in Distribution

Communications requirements Between IEDs and substation: • Legacy SCADA radios support only low‐rate data gathering (e.g. 1 phasor per second) • Wideband radio systems (2‐4 MHz bandwidth) have low latency (10‐20 ms) for distribution phasor streaming at high rates of 30‐60 per second, plus protection and control functions. • Backhaul communications with DCC – if all phasor data is sent, need 2 – 10 MHz bandwidth (latency not a big issue). • Fiber, Ethernet or serial radio, common carrier MPLS or T1. • Cellular and satellite have latency, bandwidth, availability limitations to check. • New in 2018 – cellular services that meet the latency needs may be available. © Copyright 2018 Quanta Technology, LLC

Synchrophasor Applications in Distribution

Distribution Ethernet radio systems • Wideband (2‐4 MHz), low‐latency (10‐20 ms) for distribution synchrophasor streaming plus high‐speed control for P&C. • Point‐to‐multipoint 2.4, 5.4, 5.8 GHz • WiMAX 2.3, 2.5, 5.8 GHz • Mesh radio system, 802.11 WiFi bands

Some real‐world applications…

Synchrophasor Applications in Distribution

Deployment to study PV impact • DOE study at SCE with NREL, Quanta Technology • Calabash Sub., 12 kV Fontana feeder, industrial area with large and small rooftop PV across the whole circuit. • Mall at end of circuit.

Synchrophasor Applications in Distribution

Statistical analysis – sags and swells • Assign ranges and categories to the voltage deviations. • Daily or monthly analysis of number of events and duration of each. • “Trip” refers to trip time of IEEE 1547 compliant inverter seeing this transient.

Synchrophasor Applications in Distribution

SDG&E distribution PMU application Advanced SCADA concept with PMU IEDs on circuit is driven by high penetration of distribution PV Causes voltage and PQ problems. Problems can’t be observed with existing distribution SCADA: • Updates only every few seconds. • Magnitudes of V & I only. • Accuracy not assured & can’t be assessed from data.

Synchrophasor Applications in Distribution

SDG&E distribution PMU application System with PMU data streams at 30 values per second from many circuit locations, plus other data communications functions, to support: • Voltage profile monitoring and control along the whole circuit. • Power quality monitoring. • Operational status monitoring and mitigation or improvement actions. • Faster and more selective fault protection. • Selective load shedding and restoration. • Apparatus and system condition monitoring. • System monitoring functions. Over 60 use cases or applications defined. • High‐impedance ground faults can be difficult to detect and can start fires. • PMUs and high‐speed communications led to invention of Falling conductor protection (FCP) (US patent issued; international patents pending) © Copyright 2018 Quanta Technology, LLC

Synchrophasor Applications in Distribution

SCADA system architecture Traditional SCADA with advanced overlay

Synchrophasor Applications in Distribution

Advanced SCADA PMU IEDs Example circuit IEDs with PMU and substation processing devices from Schweitzer Engineering Laboratories (SEL)®

Synchrophasor Applications in Distribution

Falling Conductor Protection (FCP) Falling overhead conductors is a common problem and fire risk. New invention using PMU IEDs and fast communications – detect conductor break and trip circuit section before circuit contacts the ground – HIF avoidance!

Conductor Height (ft)

Falling Conductor Timeline 30 25 20 15 10 5 0 0.00

d  0.5 s, 4 ft

1 g t2  t  2

2d g

2(3 0 ) 3 2 .2 tim e  1 . 3 7 s t 

1 s, 16 ft

Conductor hits ground at 1.37 s

0.25

0.50

0.75 Time (s)

1.00

1.25

Synchrophasor Applications in Distribution

SDG&E test feeder

Synchrophasor Applications in Distribution

Detection algorithms Five algorithms programmed in central controller logic: • dV/dt (voltage change detection) – fastest and most complete response; only works around change time. • V0 and/or V2 magnitude – works continuously after break • V0 and/or V2 angle ‐ works continuously after break

Synchrophasor Applications in Distribution

V2 and V0 angle methods 2

Source 1

3

4

Source 2

4

Source 2

1 PMU1

PMU2

PMU3

PMU4

FC 1 not aligned with the other PMUs

3

Source 1

1 PMU1

2 PMU2

1 and 2 aligned with each other 3 and 4 aligned with each other

PMU3

PMU4

Synchrophasor Applications in Distribution

Comprehensive RTDS testing • Circuit modeled with distributed PV. • Thousands of operating scenarios tested • Series arc of breaking conductor is modeled. • Finalized scheme showed no blind spots – multiple algorithms trip for every break simulation event. • Confirmed no FCP misoperations for normal feeder events ‐ capacitor bank switching, voltage regulator tap unbalance, single‐phase load switching, PV operation, internal and external faults.

Synchrophasor Applications in Distribution

Field installation and testing • First system installation in January 2015. • Falling Conductor Protection (FCP) tested with simulated conductor breaks (using switches). • FCP in service ‐ from monitoring mode to live protection mode. • 100% correct operation. • Ethernet radio system development required to control packet dropouts. • Now being deployed in over 12 high‐fire‐risk locations.

Synchrophasor Applications in Distribution

FCP limitations • HIF detection still needed for wire down without break. • FCP works best with a solid, fast Ethernet communications path. • Voltage needed from each protected circuit path end – system‐wide deployment is a journey of years. • New technology will have lessons learned. • Learned about insulation arcing vulnerability to trip; new logic turned this into benefit of insulation failure alarm without trip risk.

Synchrophasor Applications in Distribution

Ease of application • Key requirement achieved – no circuit‐dependent application settings • FCP logic only needs topology of circuit and PMU IEDs

Synchrophasor Applications in Distribution

Synchrophasors at 30/second show detailed circuit behavior

Synchrophasor Applications in Distribution

Conclusions – distribution PMU applications • • • • •

Growing business need for utilizing PMUs in distribution system applications. Main driver is increasing DER penetration and new loads. SCADA doesn’t show the utility what’s happening to customers. Protection and control applications are new – beyond monitoring and SCADA. Flexible platform ‐ implement many PMU applications using the same PMUs, controllers, and communications – add as they are created. • Economic factors must still be evaluated to justify widespread implementation of PMUs in distribution systems. • Many use cases and applications on one platform makes the case – departments cooperate.

• Develop a clear understanding of each application ‐ benefits and requirements. • Some must be executed in high‐speed real‐time systems. • Some can be carried out with post‐event processing of historical data.

• Biggest deployment challenges:

Synchrophasor Applications in Distribution

Questions?

Eric A. Udren eudren@quanta‐technology.com (412) 596‐6959

Quanta Technology, LLC 4020 Westchase Blvd., Suite 300 Raleigh, NC 27607 (919) 334‐3000

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Synchrophasor Applications in Distribution