Performance Evaluation of Performance Evaluation of Phasor - - PowerPoint PPT Presentation

Performance Evaluation of Phasor Measurement Systems Performance Evaluation of Phasor Measurement Systems

Henry Huang (PNNL), Bogdan Kasztenny (GE), Vahid Madani (PG&E), Ken Martin (BPA), Sakis Meliopoulos (Georgia Tech), Damir Novosel (Quanta Technology), and Jerry Stenbakken (NIST)

Performance and Standards Task Team (PSTT)

North American SynchroPhasor Initiative (NASPI)

IEEE PES General Meeting Pittsburgh, PA. July 2008 Panel: International Experience in PMU Applications PNNL-SA-60867

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US DOE NERC

What’s NASPI? North America SynchroPhasor Initiative

Vision: Improve power system reliability through wide- area measurement, monitoring and control Mission: Create a robust, widely available and secure synchronized data measurement infrastructure for the interconnected North American electric power system with associated analysis and monitoring tools for better planning and operation, and improved reliability.

2002 2003 2004 2005 2006 2007 2008 August 14, 2003 blackout EIPP

(Eastern Interconnection Phasor Project)

NASPI

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If We Knew Then…

August 14, 2003 Blackout

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15:05:00 15:44:00 16:05:00 16:09:05

Time (EDT)

Relative Phase Angle

Cleveland West MI

Normal Angle ~ -25º

Reference Angle: Browns Ferry

Slide Credit: North American Electric Reliability Corporation (NERC)

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Networked Phasor Measurement Units

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NASPI Organization

PSTT scope: coordinating and acting as liaison to standards efforts and determining consistent and satisfactory performance of synchronized measurement devices and systems by creating guidelines and reports in accordance with best practices.

• Strong international

participation

• Interoperability with IEC

61850

• Synchronization

Requirements

• PDC Hardware

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Summary of PSTT Activities

PMU Hardware Phasor Network Operations Phasor Data

PMU Installation Network Connection System Deployment Requirement Phasor Tools Synchronization Techniques HW & SW Upgrade Phase Angle Reference Phasing Survey Phase Mapping

Accomplished 2008 Goals (High Priority)

Req’t for Visualization Req’t for State Estimation

Advanced Applications & Deployment

PMU Testing And Calibration Phasor Accuracy PMU Testing And Calibration Phasor Accuracy Define PMU PMU Maintenance IED PMUs PMU Comm. Test IEC 61850 for PMU “Dynamic” Phasor

Other 2008 Ongoing

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Phasor Measurement System Instrumentation Channel: instrument transformers, cables, and burdens. Phasor Measurement Unit

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PSTT Activities in Evaluation

• f Phasor Measurement Systems

SynchroPhasor Measurement Accuracy Characterization, led by Sakis Meliopoulos: characterizing performance of instrumentation channels. PMU Testing and Calibration Guide, led by Jerry Stenbakken: standardizing methods for PMU testing and calibration. Both documents available at

http://www.naspi.org/resources/pstt/psttresources.stm

Leverage prior work and international experience in these two areas

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Other Accomplished PSTT Activities

Installation/Commissioning/Maintenance Survey & Summary, Virgilio Centeno IEDs with Integrated PMU Functionality, Damir Novosel/Yi Hu Eastern Interconnection Phase Angle Reference, Henry Huang/Ritchie Carroll Inconsistency with Phase Mapping Example, Virgilio Centeno/Henry Huang Phasor Requirements for State Estimation, Lucy Wu Phasor Requirements for Raw Data Utilization, Sakis Meliopoulos

All documents available at http://www.naspi.org/resources/pstt/psttresources.stm

Original Map: Courtesy of PNNL Communications. Information provided by Ray Hayes (AEP), and Shannon Ory (TVA).

Phase ABC Phase BCA Phase CAB

Phase ACB

A B C A B C

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Variations in Instrumentation Channel Configurations Instrument transformers

PT – Potential Transformer CT –Current Transformer CCVT – Capacitively Coupled Voltage Transformer EOVT – Electro-Optical Voltage Transformers MOCT – Magneto-Optical Current Transformers

Cables

Typically RG-8 control cable, non-twisted, unshielded

Burdens

Lack of engineering analysis and design, resulting in

inappropriate burdens and attenuator

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Current Transformer Accuracy

0.3 Class for Metering

0.3% @ 100% In 0.6% @ 10% In

0.6 Class for Monitoring

0.6% @ 100% In 1.2% @ 10% In

1.2 Class for Control

1.2% @ 100% In 2.4% @ 10% In

1.012 1.009 1.006 1.003 1.000 0.997 0.994 0.991 0.988

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+15 +30 +45 +60

lagging le ading

Phase Angle (minute s) R atio Cor r e c tion F ac tor

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Current Transformer Accuracy Curve

E r r

• r

Cur r e nt L e ve l

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Voltage Transformer Accuracy

0.3 Class for Metering 0.6 Class for Monitoring 1.2 Class for Control

1.012 1.009 1.006 1.003 1.000 0.997 0.994 0.991 0.988

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+15 +30 +45 +60

lagging le ading

Phase Angle (minute s) R atio Cor r e c tion F ac tor

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CVT Accuracy Requirements per ANSI / IEEE

1.012

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1.008 1.000 .992 .988 .986 1.004 .996 +16 +32 +63 1.014 1.010 1.006 1.002 .998 .994 .990 1.012

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1.008 1.000 .992 .988 .986 1.004 .996 +16 +32 +63 1.014 1.010 1.006 1.002 .998 .994 .990

Metering Relaying

Applic able for : Pr imar y= 90% VPe r

fR e f to 100% VMaxR ate d

Additionally: @ Vpr

imar y= 25% VPe r fR e f R

atio +/ - 3% Phase +/ - 3 de g @ Vpr

imar y= 5% VPe r fR e f R

atio +/ - 5% Phase +/ - 5 de g Plus : for 58Hz to 62Hz R CF +/ -5% & Phase +/ -5 de g vs 60Hz values Applic able for : Vpr

imar y= 90% VPe r fR e f to 100% VMaxR ate d

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Steady-State Characterization

• f Instrument Transformers (1)

220kV/115V PT 4kV/120V CCVT 60Hz 60Hz

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Steady-State Characterization

• f Instrument Transformers (2)

0.1% (Typical) MOCT Phase error due to D/A conversion. Direct use of digital signals is better. 0.648 – 1.08 deg (30 – 50 μs) 0.1% – 1% (Typical) EOVT Commonly used for HV. Need Calibration. Large error for off- nominal frequency Large error for off- nominal frequency CCVT – Very accurate Very accurate CT – Accurate Accurate PT Note Phase Accuracy Amplitude Accuracy Type

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Transient Characterization

• f Instrument Transformers

220kV/65V PT 4kV/120V CCVT

50 100 150 200 250 300 350 8.0000 10.0000 12.0000 14.0000 16.0000 18.0000 20.0000 22.0000 24.0000 Prim ary Voltage (kV) Time (Milliseconds) 0.0 20.0 40.0 60.0 80.0 100.0 120.0 8.0000 10.0000 12.0000 14.0000 16.0000 18.0000 20.0000 22.0000 24.0000 Time (Milliseconds) Secondary Voltage (V)

0.02 0.04 0.06 0.08 407

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High Capacitance CCVT Response Extra High Capacitance CCVT Response Input Voltage is Zero Beyond This Point Voltage (kV)

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Characterization of Instrumentation Cables

0.015 0.012 0.010 0.008 20k 0.015 0.012 0.010 0.008 10k 0.015 0.012 0.009 0.007 5k 800 ft 500 ft 200 ft 100 ft Burden Resistance RB (Ω) Instrumentation Cable length ℓ (ft)

Amplitude Error in %

0.18 0.12 0.08 0.05 20k 0.18 0.12 0.08 0.05 10k 0.23 0.15 0.10 0.07 5k 800 ft 500 ft 200 ft 100 ft Burden Resistance RB (Ω) Instrumentation Cable length ℓ (ft)

Phase Error in Deg

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Example of Overall Channel Characterization

Voltage Measurement, 69 kV Bus RG-8 Cable, 500 ft 69kV:69V Wound Type VT

NORTHBUS3 NBUS3MS NBUS3MSI

Vcn = 62.33 kV / 147.46 Deg Vbn = 62.96 kV / -92.68 Deg Van = 62.53 kV / 27.52 Deg Vcn = 61.99 V / 147.45 Deg Vbn = 62.61 V / -92.70 Deg Van = 62.19 V / 27.51 Deg Vcn = 61.72 V / 148.00 Deg Vbn = 63.09 V / -92.85 Deg Van = 61.63 V / 27.11 Deg

VT: error = 0.01 deg; Cable: error = 0.4 deg Calibration:

Correction based on instrumentation channel models Local state estimation (SuperCalibrator)

VT VT-

• based Instrumentation Channel

based Instrumentation Channel

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PMU Performance Evaluation IEEE C37.118 SynchroPhasor Standard

Metrics mainly on steady-state performance

WECC established monitoring requirements

Metrics mainly on filtering performance

frequency voltage signals current signals phasors

PROTECTIVE INTERFACE PRE- CONVERSION FILTERS A/D CONVERTER REFERENCE SIGNALS POST- CONVERSION FILTERS & DECIMATION

BUS FREQUENCY ESTIMATOR

GUARD FILTER OUTPUT FILTER OUTPUT DECIMATION SECONDARY CALCULATIONS

derived quantities

NOTE: Indicated filters may be accompanied by decimation without actual filtering

SAMPLING CLOCK

PHASOR ESTIMATOR

Time reference

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PMU Testing Setup

Signal Generator Signal Generator

Data Collection Device

PMU under test

GPS Antenna Setting and Control Playback Files Setting and Control Setting and Control Analysis Tools Other Measurement Devices

GPS Receiver

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Steady-State PMU Testing Magnitude accuracy test* Phase accuracy test* Frequency accuracy test* Rate of change of frequency accuracy test Unbalanced magnitude response test Unbalanced phase response test Off-nominal frequency response test* Harmonic frequency response test* Out-of-band interference test* Data reporting test

“*” conform to IEEE C37.118

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Dynamic PMU Testing Dynamic magnitude response test Dynamic phase response test Dynamic frequency response test Voltage amplitude modulation test Frequency modulation test

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Example of PMU Testing Results

0.28 1.4 6.64 12 15 21.72 28.72 30.85 36.89 45 30

input modulation frequency (Hz) PMU output frequency (Hz)

0.28 1.4 6.64 12 15 8.28 1.28 0.85 6.89 15

PMUtests_AMod6006seriesA

PMUtests_AMod6006seriesA 07/27/05_12:58:58

80 100 120 60.05 60.1 218 220 222 224 226 228 230 232 234 236

Time in Seconds

PMUA Bus Voltage VMag PMUA Bus Voltage FreqLX 0.28 1.4 6.64 12 15 21.72 28.72 30.85 36.89 45 30

input modulation frequency (Hz) PMU output frequency (Hz)

0.28 1.4 6.64 12 15 8.28 1.28 0.85 6.89 15 0.28 1.4 6.64 12 15 21.72 28.72 30.85 36.89 45 30 0.28 1.4 6.64 12 15 21.72 28.72 30.85 36.89 45 30

input modulation frequency (Hz) PMU output frequency (Hz)

0.28 1.4 6.64 12 15 8.28 1.28 0.85 6.89 15 0.28 1.4 6.64 12 15 8.28 1.28 0.85 6.89 15

PMUtests_AMod6006seriesA

PMUtests_AMod6006seriesA 07/27/05_12:58:58

80 100 120 60.05 60.1 218 220 222 224 226 228 230 232 234 236

Time in Seconds

PMUA Bus Voltage VMag PMUA Bus Voltage FreqLX

PMUtests_AMod6006seriesA

PMUtests_AMod6006seriesA 07/27/05_12:58:58

80 100 120 60.05 60.1 218 220 222 224 226 228 230 232 234 236 218 220 222 224 226 228 230 232 234 236

Time in Seconds

PMUA Bus Voltage VMag PMUA Bus Voltage FreqLX

Steady-State Amplitude Amplitude Modulation

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“Dynamic Phasor” Total Vector Error for a PMU relative to fundamental and dynamic phasors

Concurrent 10% phase modulation and 10% amplitude

modulation from 1 to 71 Hz

1 2 3 4 5 6 7 8 9 10 1 10 100

Modulation Frequency in Hz

Fundamental Phasor Dynamic Phasor

TVE in %

Nyquist Frequency

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Implications of Phasor Measurement Quality

Level of accuracy requirements is highly related to applications For monitoring, both amplitude and phase errors would result in false alarms. For special protection, amplitude and phase errors would result in false arming. For state estimation, small phase error may result in large discrepancy in power flow. For control, phase error (time delay) leads to unexpected control output, and thus unexpected (usually deteriorated) control performance Characterization and calibration are important to ensure phasor quality.

30 60 90 120 150 180 0.2 0.4 0.6 0.8 1

angle in degrees sin(x) 0.074 or 7.4% 5 degrees

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Routine Maintenance Routine Maintenance complementary to characterization, testing, and calibration.

PMUs may undergo many revisions after installation—

i.e., laboratory results may no longer be representative.

Cable configurations, and instrument transformer

characteristics may change over time and should be examined regularly.

Impact of the changes should be characterized, and

may be minimized or compensated in phasor measurement.

The PSTT team initiated an effort in developing a PMU maintenance guide based on BPA experience.

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Summary

Performance evaluation of instrumentation channels and PMUs is important for phasor applications. The NASPI PSTT team’s efforts on: 1) PMU Testing and Calibration Guide and 2) SynchroPhasor Accuracy Characterization

Objective: facilitate phasor network deployment and phasor

applications.

Audience: both vendors and users.

Performance evaluation of phasor measurement systems call for all the following three aspects:

Model studies Laboratory testing Field evaluation and maintenance

Ongoing PSTT work includes PMU commissioning tests, PMU maintenance guide, evaluation of multi-function phasor measurement devices, and PDC functional requirements.

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Questions?

Zhenyu (Henry) Huang, PNNL 1(509) 372-6781, zhenyu.huang@pnl.gov