1. technology and computing

Volume 5, Issue 3 • Fall 2014
QT e-News™
QUA NTA T E C HN OLOG Y’S ON LIN E N E WSLE T TER
Power Hardware-in-Loop Testing for Smart Inverters
By Farid Katiraei, Executive Advisor & Director, Renewables
Increased penetration of distributed energy resources (DERs) and interest in improved reliability, power
quality and resiliency of the grid have changed the
characteristics of distribution systems and the design of the distribution system. Bidirectional power
flow and events with fast dynamics are becoming
a more common occurrence. Understanding these
issues requires a deep knowledge of distribution
system dynamic behavior supported by detailed
engineering studies and sophisticated testing
methods.
Figure 1 – Advancement in Testing Methods
With the deployment of renewable energy based
generation (PV, wind, etc.) and the advent of
various advanced automation and smart grid
technologies, power distribution companies (utilities)
have been experiencing a proliferation of power
electronics-based energy conversion devices at medium and low voltages. Power electronics are now
regularly used as the interface for solar PV systems
(PV Inverters), variable speed wind turbines (Wind
Inverters), and battery and flywheel energy storage
systems.
Continued on Page 3
Inside This Issue:
Power Hardware-in-Loop Testing for Smart Inverters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1
Letter from the President........................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Increased Efficiency of RTDS Testing Due to Automation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
Use of High-Voltage Optical Sensors for Field Verification & Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 9
International Spotlight .............................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 11
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Page 2
Q UA NTA T E C HN OLOG Y’S e-N E WS
L E T T E R FROM TH E PRESID EN T
Strengthen Testing to Strengthen the Grid
Dear Colleagues,
The electrical power industry is under significant pressure to
safeguard the reliability, quality and resiliency of the power grid as
industry standards and consumer expectations continue to evolve.
A combination of conventional and advanced solutions is essential
to meet these challenges.
Quanta Technology continues hiring present and future industry
leaders to combine its deep knowledge and experience with leading
edge, advanced technology to provide solutions for the industry
using a holistic, forward-thinking approach to ensure the overall
integrity of the power system. This issue of the newsletter highlights
how technical advancements in the area of Testing can make a
notable and positive contribution to overall system integrity.
For example, business models of the energy sector have evolved
substantially with the adoption of new grid configurations such
as Distributed Energy Resources (DERs) and microgrids. DER
interconnection to the distribution grid represents a challenge as,
traditionally, the large majority of distribution facilities have been designed to be operated in a radial fashion with unidirectional forward
power flows.
One of the most prominent efforts to address industry needs is
embodied in the IEEE 1547 Series of Interconnection Standards,
including voltage regulation and control via DG units, and voltage
and frequency ride-through during disturbances. "Smart" inverters
are critical to achieve desirable performance and their functionality
is addressed by standard revisions. Farid Katiraei writes about how
the Power Hardware-in-Loop (PHIL) approach for testing smart in-
verters is cost effective and provides more precise
performance evaluation results that will, in turn,
help with standard updates.
As power grids worldwide have become more
complex to operate, protection and control applications need to
accommodate to grid changes. It is of utmost importance to perform
comprehensive, but efficient, automated tests of those applications
using state-of-the-art tools so experts can focus on finding and
resolving problems. Juergen Holbach and the Automation & Testing
team discuss how power system control and protection applications
have benefited from using RTDS testing, in that a combination of
testing automation and process enhancements can reduce RTDS
testing timeframes, while improving the quality of the results.
Another important aspect of monitoring, protecting and controlling
the grid is achieving high accuracy of measurements, with voltage
and current transducers being critical elements in the measurement
chain. Farnoosh Rahmatain reviews how the compact size, high accuracy and exceptional isolation ability of optical voltage and current
sensors make them ideal for mobile and portable field applications
to ensure the integrity of voltage and current measurement devices.
The electrical power and energy industry is in a crucial transition, as
the initiatives we take today will affect how the grid is operated for
years to come. Let's continue our important work for the betterment
of utilities and consumers alike.
Sincerely,
Damir Novosel and the Quanta Technology Team
Recent Quanta Technology Presentations & Publications
"Planning and Managing Urban Core Power Delivery Systems" by L. Willis – EUCI Course, August 4-5, Baltimore, MD
"Accuracy, Calibration & Interfacing of Instrument Transformers with Digital Outputs" by F. Rahmatian, CIGRÉ, August 24-29, Paris, France
Keynote address: "Sustainable Energy Trends, Opportunities, and Challenges" by D. Novosel – IEEE T&D Latin America, September 9-13, Medellin, Columbia
"Smart Grid Communications" by S. Ward – Disturbance Analysis Conference, September 8-9, Medellin, Colombia
"A Methodology Based on Disturbance Analysis for PMU Applications Prioritization in the Colombian Electric Power System" by D. Elizondo – Disturbance Analysis
Conference, September 8-9, Medellin, Colombia
"Redundancy Considerations for Protective Relaying" by S. Ward – Disturbance Analysis Conference, September8-9, Medellin, Colombia
"Hidden Failures in Protection Systems and its Impact in Wide-Area Disturbances" by D. Elizondo – Disturbance Analysis Conference, Sept 8-9, Medellin, Colombia
"Application of Robots for Inspection and Maintenance of Transmission Lines" by D. Elizondo – IEEE PES T&D Latin America, September 10-13, Medellin, Colombia
Keynote address: "Grid Reliability Improvements with Wide-Area Monitoring, Protection and Control" by D. Novosel – PAC World Americas Conference, September
23-25, Raleigh, NC
"SIPS in the Colombian Interconnected Power System - Towards an Improved Definition, Application and Delineation of Roles and Responsibilities" by D. Elizondo,
S. Ward, et al – PAC World Americas Conference, September 23-25, Raleigh, NC
"Evaluating Relay Performance during Power Swings and Associated Dynamic Events" by A. Gopalakrishnan, B. Gwyn – PAC World Americas Conference, September
23-25, Raleigh, NC
"Principles for Practical Wide-Area Backup Protection with Synchrophasor Communications" by E. Udren – PAC World Americas Conference, September 23-25,
Raleigh, NC
"Supply Chain Management – Sourcing Strategy from a Protective Relay Perspective" by S. Ward – PAC World Americas Conference, September 23-25, Raleigh, NC
"Modeling Issues: How to Comply with MOD-026& 27" by A. Schneider – North American Generator Forum, October 8, Atlanta, GA
"Roadmap and Lessons in Deploying Large Scale Synchrophasor Systems" by F. Rahmatian, et al. – CIGRÉ Grid of the Future, October 19-21, Houston, TX
"Reliability Analysis" by L. Xu – DNV GL International Software Summit, October 27-28, Houston, TX
"Time Series Simulation for Slow Dynamic Analysis in Distribution Systems with DERs" by L. Yu and J. Romero Agüero – Cigré Grid of the Future, October 19-21,
Houston, TX
"Transmission Line Automated Relay Coordination Checking" by S. Alaeddini, et al – Minnesota Power Systems Conference, November 4-6, Minneapolis, MN
QUA NTA T E C HN OLOG Y’S e-N E WS
Page 3
Power Hardware-in-Loop Testing — Continued from page 1
Power electronic converters are also
fundamental building blocks of emerging power conditioning apparatus in
distribution systems. They are used in
equipment such as static reactive power
compensators and voltage regulators
(D-STATCOM, DVC, DVAR, etc.), Solid
State Transformers (SSTs) and active
filters for power quality improvement.
To reliably introduce a new power conditioning device or generation facility into
the system, a series of resource evaluations and detailed planning studies will
be needed to determine possible impact
on the system and suggest corrective
actions. In addition, extensive field
testing and performance analysis during
the commissioning period is required to
ensure proper integration into the area
Electric Power System (EPS).
A clear understanding of dynamic performance and the ability to properly model
inverters and power electronic apparatus
have been the key challenges facing
utility engineers and their consultants. To
underscore the issue, understanding the
expected level of current contribution by
PV inverters and modeling their response
during faults and typical grid
disturbance (e.g., voltage sag
initiated through transmission
faults) have been a key discussion point between utilities,
inverter vendors and facility
developers.
To effectively study a power
electronic device or a generation
facility utilizing multiple power
Figure 2 – UL1741 Inverter testing method with load banks
convertors, information about
the control and protection capa- (in the middle) and a voltage source (simulated utility)
bilities should be available. The
Gaps in Current Testing Practice
information should provide detail insights
& Certifications
into expected dynamic response and the
possible interaction with other devices to In the current practice and testing of PV
inverters or power electronic converters
allow accurately performed impact studies. Such studies should include detailed provided by certification agencies (e.g.,
UL1741 method shown in Figure 2), a
analysis of system faults and voltage
power electronic apparatus is tested at a
disturbances. Knowing detailed device
device level rather than the system level.
models and being able to characterize
This is accomplished through applying
dynamic behavior of power electronic
a load bank and a controlled voltage
interfaces are expected to become more
source that may not reflect effect of any
and more critical and raise questions
source impedance (infinite bus represenas new smart control functionalities
tation), or complex response of nonlinear
and combining generation and power
loads. The tests are focused on verificaconditioning capabilities are introduced
through emerging Smart Inverter technol- tion of certain aspects of control and proogies.
Figure 3 – An example of Power Hardware-in-Loop setup for the next generation of testing meth-
Continued on page 4
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QUA NTA T E C HN OLOG Y’S e-N E WS
Power Hardware-in-Loop Testing — Continued from page 3
tection design for one device of a specific
type. This approach is used even though
most utility scale DER installations will
include multiple inverters connected in
parallel or distributed across an area with
connection points on a collector system.
Another concern with the device level
testing is that they will not be able to
characterize typical dynamic interactions
and responses seen at primary system
level (12 kV or 25 kV feeders).
In general, present certification testing
practices lack proper focus and examination of the following areas:
• No consideration of area EPS characteristics during the test, such as grid
impedance, voltage level and stiffness
• Gross simplification of the interconnection system configuration, such as
step-up transformer topology and
grounding practices, as well as vicinity
to conventional voltage control devices
on distribution systems (e.g., line
voltage regulators, shunt capacitors,
etc.)
• Ignoring the impact of multiple
homogeneous or heterogeneous
devices operating in parallel or in the
vicinity of each other
• Ignoring the device operation and
controllability through communication
schemes
Currently, inverter manufacturers do not
provide detailed models of their inverter
designs and internal control schemes.
Without this information, many aspects
of the aforementioned system impacts
cannot be readily investigated and clearly
understood.
It is understood that there will always
be limitations in how much can be
modeled and the fact that transient
study approaches may not cover every
condition of the system. Nonetheless,
new initiatives by the IEEE 1547 working
group and several state/federal regulatory agencies are currently in progress
to define new testing methodologies and
processes that can capture and verify
the complex nature of smart inverters
in terms of impact on the area EPS
and take into account the impact of the
communications infrastructure and effect
of remotely changing control settings.
These efforts are currently in the early
stages of development and will require
extensive involvement of stakeholders
and experts from utilities, industry and
vendors to determine appropriate testing
methodologies.
Until such issues are addressed by the
industry, Quanta Technology experts
have been focusing on applications and
utilizations of real-time hardware-in-loop
(HIL) testing approaches for detailed
evaluation of intelligent electronic
devices and power electronic apparatus
involving complex control, protection and
fast-acting power electronics.
Real-Time Digital Simulation
Testing
Power hardware-in-loop (PHIL) testing uses real-time digital simulation
approaches through RTDS or similar
platforms and provides the ability
to interface off-the-shelf commercial inverters and power electronic
devices for closed loop testing. PHIL
allows the creation of conditions
which, from the inverter point of view,
are indistinguishable from those in
the field. This approach allows for
an accurate observation of inverter
control responses and assessment of
impact on the system.
A typical PHIL setup for PV inverter
testing is shown in Figure 3. In this
figure, the device under test (DUT)
is a 100 kW PV inverter developed
for the North American market, being
installed in the field. The inverter
comes with an internal 480 V AC isolation transformer. The 480 V threeFigure 4 – PV Inverter currents and voltages for a three phase fault at 12 kV about 2 miles away from POI
Continued on page 5
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QUA NTA T E C HN OLOG Y’S e-N E WS
Power Hardware-in-Loop Testing — Continued from page 4
phase connections
for the inverter are
provided through a
grid simulator, carefully sized according to
the kVA rating of the
inverter under test.
In this application, the
grid simulator acts as
a regenerative, linear
power amplifier, receiving low level voltage signals (±10V)
from the RTDS and
amplifying the signals
to the inverter AC
voltage range (480V
in this case). Using
this approach, the
grid simulator will be
able to sink current
Figure 5 – PV Inverter currents and voltages for a line to ground fault at 12 kV about 2 miles away from POI – delta
from the DUT (inverter) high side transformer
and re-circulate into the
To close the loop, the instantaneous
aspects of the PV inverters without any
main power supply to drastically reduce inverter currents measured at the insimplification.
power consumption and any need for
verter terminals are monitored by RTDS Conclusion
extensive heat dissipation.
analog input cards (using measurement
PHIL testing which utilizes the approach
In the field, the input to the inverter is
CTs and linear current/voltage transdescribed above is cost effective and
typically generated from several arrays
ducers) and injected into the simulated
provides precise performance evaluaof PV panels providing up to 600-800
model at the low side of the intercontion results in situations, such as:
Volt DC (open-circuit voltage). The spe- nection transformer. Lab tests should
cial current-voltage characteristics of
PV panels are created by a PV simulator in the laboratory environment.
In the PHIL test setup that is used to
test inverter impact on area EPS, the
grid simulator voltage will be controlled
by the RTDS to represent the monitored
voltages at the inverter point of interconnection ("POI"). Depending on the
tests, a detailed simulated model of the
entire area EPS (distribution circuit) at
MV level (12 kV, 25 kV, or 35 kV) can
be used to capture the voltage variations at POI due to change in loads,
operation of voltage control devices and
power injection of the PV inverter. The
simulated model can also incorporate
the interconnection transformer characteristics and topology that is essential in
the grid impact evaluation.
be designed using special care and
consideration to take into account the
possible delays and signal conversions
within the lab set up. If not, delays in
the closed loop or deterioration of the
waveform content due to bandwidth
limitation of the I/O cards may be
introduced.
Examples of current and voltage
measurements from selected 12 kV
fault tests performed on commercial
PV inverters with the use of Quanta
Technology’s PHIL test setup are shown
in figures 4 and 5. The results clearly
show the transient behavior of PV
inverter currents in response to threephase and single-phase faults applied
at 12 kV. Using this approach, Quanta
Technology is able to fully represent
and evaluate the protection and control
• Certification testing of smart
inverters and power electronic
apparatus, in general
• Multiple inverter testing for high
penetration of DERs and PV
inverter clusters
• Integrated testing of devicelevel and/or plant-level control
and operation through communications and remote operator
commands
• Microgrid control/protection
scheme tests and islanding
capability
• Volt/VAR management
schemes with power electronics
and DERs 
Page 6
QUA NTA T E C HN OLOG Y’S e-N E WS
Increased Efficiency of RTDS Testing Due to Automation
By Juergen Holbach, Senior Director & Solveig Ward, Principal Advisor, Automation & Testing; Farid Katiraei,
Executive Advisor & Director, Renewables
Testing with an RTDS system has shown significant value in
testing power system control and protection applications. This is
particularly true for complex applications or for new applications
where no proven standard solution is available. RTDS testing
is able to interact with the system under test in real time and
thereby find weaknesses and problems as they would appear in
the applications, allowing them to be resolved before they cause
any misoperation in the power system.
This alone makes a powerful argument for conducting RTDS
tests and consequently, generation, transmission and distribution
owners, as well as manufacturers, are increasingly using this
approach of testing.
On the other hand, conducting RTDS testing is a budget and resource commitment which should not be underestimated. Quanta
Technology has extensive experience in RTDS testing based on
our work with utilities and manufacturers from all over the world.
This article describes how we have utilized a combination of testing automation and process enhancements to reduce the time it
takes to conduct RTDS testing, while simultaneously improving
the quality of the results.
Defining Test Plan
Test Definition
A Typical RTDS Project
A typical RTDS project consists of the three major phases:
1- Test Definition
The definition of the Test Plan is a key task that influences all the
tasks that follow. The test plan should give a detailed description
of the power system to be simulated in the RTDS and include a
list of all the test scenarios to be conducted. The test plan also
describes the hardware under test and how it will be connected
to the RTDS, as well as a list of all signals exchanged between
the RTDS and the hardware under test.
2- Test Setup
The Test Set-Up phase has two major tasks which run in parallel.
The first addresses all the programs which need to be developed, while the second deals with the actual hardware setup and
wiring.
Programming The RTDS programming itself can be split in
three different tasks:
•
•
Test Scenarios
Hardware/Connections
Hardware
Software
Building Power
System Model
Test Setup
Program Control
Elements & Logic
Building
Hardware
Test Setup
Program Script
Files for
Automation
Conduct Test
Test Run
Summarize Test Results
Evaluation
Figure 1 – Phases of a typical RTDS testing project
•
Building the power system model - The power system model
provided by the customer is programmed into RSCAD to get
it into a format usable by the RTDS.
The programming of the control element and logic builds the
interface to the hardware setup on one side (Which breaker
should be operated by which input on the RTDS from a relay
under test?) and to the test interface on the other side (How
is a fault on location x triggered by a user?)
The programming of the Script file is not required, but needed
if tests should be automated. Based on the test plan, the
script file will use the programmed test interface to activate
the test cases as specified.
Hardware Setup The hardware setup includes the connection of all hardware components under test to the interfaces of
the RTDS (inputs/outputs), as well as the required connections
between the hardware components (e.g., simulated Power Line
Carrier channel between protection relays). In this phase all
hardware components will be configured as planned for the real
application. The development of the configuration and settings
is normally not part of the RTDS testing, but may be required by
the client as part of the RTDS test project.
The Test-Setup task is finished after the test system is commissioned. The commissioning requires the testing of the functionality of all signals and interfaces, as well as the verification of the
accuracy of the simulation cases using reference fault records or
simulation results.
Continued on page 7
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QUA NTA T E C HN OLOG Y’S e-N E WS
Increased Efficiency of RTDS Testing — Continued from page 6
3- Test Run
The last phase is the actual test run during which the test
cases are performed either manually via a graphical user interface or automatically with a script file. The manual method
via the graphical interface is useful during the commissioning
phase where a detailed review of results after each test is the
preferred approach to detect any issues. Once the accuracy
of the set-up is verified, an automated test via scripted files is
preferred. The evaluation of the test results requires a Subject
Matter Expert (SME) to review the performance of the system
under test and document the findings. Having a good reporting tool and process is a key element in this phase.
RTDS testing is an iterative process and as issues are identified, changes to settings, hardware set-up, power system
model and/or test plan are required and followed by re-runs of
the tests. The more intelligent the methodology and the more
automated the process, the more time the SME can focus on
real issues instead of routine evaluations, and the more the
overall time to complete the work is reduced.
Test Plan Description
Script Input File
Automated
Generation
of
Script File
Script Program File
Advanced Automation & Testing Process Used by Quanta
Technology
Our goal has therefore been to optimize the process to
ensure all necessary tests are conducted as efficiently as
possible, and we have accomplished this as follows:
Reduced number of repetitions stemming from
human error The test plan is a key input to most of the tasks
that follow. Testing personnel utilize the test plan to assemble
and wire the test-setup. Any misinterpretation of the requirements can lead to wiring errors which, if not caught during
initial commissioning, will require re-testing.
Test Plan Description
Figure 2 – Automated script file generation
Another source of error is the programming of the script files
and as above, misinterpretation of the requirements can lead
to scripting errors and subsequent re-testing. Our solution to
these problems is to automate the script file generation based
on a standard format test plan.
Automatic Generated Summary of Test Results
Standard RTDS Output
→ n-COMTRADE Files
Hyperlink
Functionality
for Detailed
Review
Figure 3 – Automated generation of test results
Continued on page 8
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QUA NTA T E C HN OLOG Y’S e-N E WS
Increased Efficiency of RTDS Testing — Continued from page 7
Figure 4 – Evaluation of test results support by Expert System
The advantage of this approach is that the interpretation
of the test plan is performed by the program and will
always be correct as long as the test plan follows the standard defined format. Moreover, the creation of the script
file is done instantly, which eliminates an otherwise time
consuming and repetitive task.
Automated generation of test report The use of
script files generates a lot of test results quickly, which
then results in a new challenge – how to handle the data
overload? It is important to summarize the results in a
format that is easy for the Subject Matter Expert to read
and analyze, and RTDS provides several documentation
formats.
Quanta Technology uses the COMTRADE file format for
all test results because of the high degree of flexibility
offered in the selection of signals needed for the evaluation without requiring any complex programming in the
RTDS. We have automated the process of interpreting
the COMTRADE files, measuring important values and
displaying the results in an agreed upon customer format.
The standardized Test Plan description is used to control
the content of the test result report.
Defining Test Plan
Test Definition
Test Scenarios
Hardware/Connections
Hardware
Software
Building Power
System Model
Test Setup
Program Control
Elements & Logic
Building
Hardware
Test Setup
Program Script
Files for
Automation
Conduct Test
Test Run
Summarize Test Results
Test result evaluation support by Expert Sytem
The evaluation of test results is a task which can never
Evaluation
Automated
be fully automated – the SME is still necessary. However,
our experience has shown that in some cases, simple
rules can be used to determine the correct and desired
Figure 5 – Automated RTDS testing in Quanta Technology
operation for a given scenario. This rule engine can be used
to quickly flag obvious problems early in the process and
Summary
speed up the process of evaluating the results. Quanta TechThe test automation we utilize has resulted in much more
nology has developed an Expert System that color codes the reefficient use of resources during testing, thereby allowing our
sults based on rules entered by the user. Obvious problems are
experts to focus on the actual task of finding and resolving
flagged in red, while potential problems are identified in yellow.
problems. 
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QUA NTA T E C HN OLOG Y’S e-N E WS
Use of High-Voltage Optical Sensors for Field Verification
& Performance Validation
By Farnoosh Rahmatian, Senior Director & Executive Advisor, Measurement Devices
Optical voltage and current sensors
can have many attractive performance
features including high accuracy, excellent linearity and wide bandwidth. They
also offer compact size and exceptional
isolation from high-voltage (HV) conductors. Accordingly, they can be used as
portable or mobile sensors measuring
and validating the performance of HV
instrumentation, measurement, protection
and control system. In this article, we
will briefly review sample applications of
mobile high-voltage optical testing systems, including live 500 kV VT calibration,
synchrophasor system calibration and
validation, and HV power quality and
harmonics measurement.
In the transition to a smarter and more
accurately monitored and controlled grid,
there is a need for calibrating the present
voltage and current measurement devices
on the grid, as well as validating the
performance of the novel protection and
control systems driven from these measurement devices. Optical sensors can be
connected safely to a live HV line and can
be used as transfer standards for calibrating live instrument transformers. Avoiding
power outages, otherwise necessary for
calibrating HV instrument transformers,
provides a significant value for the electric
system owners and operators.
An example of a portable calibration
system, using a reference 550 kV class
optical VT (OVT), has been presented
in [1] and [2]. This system, in various
configurations, can be used for calibrating
revenue metering class VTs, as well as
validating synchrophasor measurements
(and State Estimation applications using
synchrophasor data) at up to 550 kV.
The OVT has two separate secondary
analog outputs: low-energy (<10 V rated)
and high-energy (69 V or 115 V rated).
The low-energy analog (LEA) output is intended to be used within a synchrophasor
Figure 1 – Schematic of a single-phase voltage accuracy verification and calibration system. The
optical VT and its associated electronics chassis in the control room serve as a reference standard
VT for comparison with the CVT under test.
test system for connection to a reference
low-voltage phasor measurement device.
The high-energy analog (HEA) output is
intended for use in calibration of voltage transformers directly (connected to
calibration bridges). Both LEA and HEA
outputs provide traceable uncertainty of
less than 0.1% in amplitude and 1 milliradian in phase.
The OVT also has full BIL rating (lightning
impulse withstand) for a 550 kV class
system at 1800 kV peak and can remain
on a 500 kV system for a long time when
necessary. Figure 1 shows a schematic of
a single-phase voltage accuracy verification and calibration system using the
OVT. In its simplest form, the test system
provides a reference for comparison (via
a traditional balancing bridge) with the
secondary signal from the capacitive VT
under test. Figure 2 shows a picture of
an OVT being connected to a live 550 kV
bus without line/bus outage.
Figure 3 shows an example of data
obtained using the same 550 kV portable
optical voltage transformer for on-site
measurement of harmonics near a Static
VAR Compensator (SVC) substation.
In this case, voltages up to the 25th
harmonic (1500 Hz) were measured. The
LEA output of the OVT was used for the
measurement. This testing was part of a
commissioning test, to validate if the electronic switching used in the SVC system
had proper timing and performance. In
this case, switching timing errors would
have given rise to significant {6n±1}
harmonics (i.e., 5th, 7th, 11th, 13th, 17th,
19th, 23th, and 25th harmonics). The
primary voltage and the total harmonic
distortion (THD) were also measured
over a period of time to validate proper
Continued on page 10
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QUA NTA T E C HN OLOG Y’S e-N E WS
Use of High-Voltage Optical Sensors
— Continued from page 9
performance of the SVC system,
making sure that limits given in
standards such IEEE Std. 519,
"IEEE Recommended Practice and
Requirements for Harmonic Control
in Electric Power Systems," weren’t
violated.
Ultimately, voltage and current
measurement devices are the eyes
and ears of the electric power grid.
Optical voltage and current sensors
can provide superior “seeing” and
"hearing" capability and, thanks to
their light weight and compact size,
can be used effectively in the field for
observing the performance of various
devices, systems and applications.
Fiber optic sensors also provide
excellent isolation between HV
lines and ground, and they can be
deployed without noticeably affecting
the system they test. As such, they
are very suitable for field testing and
calibration purposes. 
Figure 2 – OVT connecting to a live 550 kV bus without line/bus outage [1]
References:
[1] F. Rahmatian, J. H. Gurney,
and J. A. Vandermaar, “Portable
500 kV optical Voltage Transducer for On-site Calibration of
HV Voltage Transformers without
De-energization," in Proc. CIGRE
General Session 41, 2006, paper
A3-103.
[2] E. Udren, F. Rahmatian, Y.
Hu, V. Madani, and D. Novosel "In-Field Synchrophasor
System Calibration, Testing,
and Application Validation Using
High-Voltage Optical Sensors,"
in Proc. CIGRE General Session
44, 2012, paper A5-111.
Figure 3 – Field measurement of voltage harmonics using a 550 kV portable OVT. Values up to the 25th
harmonic were measured. The fundamental frequency of the system was 60 Hz. The LEA output of the
OVT was used for the measurement. [3]
[3] F. Rahmatian and A. Ortega,
"Applications of Optical Current and Voltage Sensors in
High-Voltage Systems," Proceedings of the IEEE-PES T&D Latin
America, Caracas, Venezuela,
Aug. 2006, paper 471.
QUA NTA T E C HN OLOG Y’S e-N E WS
Page 11
INT ER NATION AL SPOTL IG H T
Latin America
The Quanta team traveled to Ecuador in September to kick-off the
(L-R) QT's Dabeginning of a new Protection Auditing project for Centro Nacional de
vid Elizondo,
Control de Energía (CENACE). Events occurred in the National SysPAC World Edtem of Transmisión (SNT) in 2012 which necessitated a project that
itor-in-Chief,
would audit the electrical protections, as well as determine a diagnosis
Dr. Alex
of the present states, and that would allow the implementation of a
Apostolov, and
QT's Solveig
system of management for the information handling, maintenance and
Ward after
renovation of the systems of protection pertaining to the SNT.
presenting
During the kick off meeting, Quanta Technology worked with CENACE
together in
to establish a base understanding of the current state of protections,
Medellín,
norms and standards of protection, planned expansions, optimal
Colombia.
protection statuses and finally analyzing ten key past events. The successful execution of this important project will facilitate a more reliable
and secure SNT.
In September, Quanta supported XM in hosting a Protection conference in Medellin, Colombia. Quanta Technology brought industry leaders like PAC World Editor & Chief Dr. Alex
Apostolov, Mohamed Ibrahim and Virginia Tech’s Dr. Jaime De La Ree who all presented at
the event, as well as Quanta Technology team members Solveig Ward and David Elizondo.
The event was well attended and an exciting step forward in Colombia’s embrace of cutting
edge Protection technology and best practices. XM’s own Jorge Vélez wrote to us afterwards
in describing the success of the event, "Creo que marcamos un hito en el país." (I think we
set a milestone in this country.)
Quanta Technology President and IEEE PES President Elect, Dr. Damir Novosel, and QT’s
International Director Dr. David Elizondo also attended the 7th edition of the IEEE PES Transmission and Distribution Conference and Exposition – Latin America, which was also held in
Medellin, Colombia. This event included presentations and technical papers from recognized
Dr. Damir Novosel giving his keynote speech international experts. Dr. Novosel gave the keynote speech on "Opportunities for Sustainable
at the IEEE PES T&D Conference in Colombia
Power Grid Improvements.” Dr. Elizondo and Quanta Energized Services' Ray Gibler gave
in September.
a tutorial on "Ground Based Robots & the Future of Applications of Robots for Transmission
Line Work." This tutorial highlighted both Quanta's previous extensive work with energized
projects and patented technology like the LineMaster™ robotic arm, as well as emerging key technologies such as the increasing
use of UAVs (unmanned aerial vehicles).
Far East
In June, the Quanta team went to Kuching, Malaysia, to perform RTDS testing
of Siemens and ABB protection relays in order to test the performance on three
different 275kV transmission lines for Sarawak Energy. Quanta Technology was
responsible for the development of the power system model, the test plan, development of the protection settings, the test execution, and the test evaluation and
documentation.
Dr. Juergen Holbach and Solveig Ward (center left) with SEB in the lab in Malaysia and
a street view of the New Sarawak State Legislative Assembly building in Kuching.
Page 12
QUA NTA T E C HN OLOG Y’S e-N E WS
W ELCOME OU R N E W PEOPLE
Evan Estes, Business Development Manager, Midwest &
South Central Region, has
over 12 years of transmission
planning and business development experience. Most recently Evan was Development
Project Manager with NextEra
Energy. He holds a Bachelors
in Electrical Engineering from
Missouri University of Science
& Technology, and will be
based in the St. Louis area.
Rahul Anilkumar, Engineer,
graduated with a Masters in
Electrical Power Engineering,
May 2014. He has two years of
active Research Experience in
the fields of transmission and
distribution planning, renewable integration and algorithm
development, and multiple
internships in the fields of data
center design, automation and
power quality.
Xinyu Tony Jiang, PhD, Senior
Engineer, Transmission, has
several years of experience in
power system synchrophasor
applications, state estimation
methods and electromechanical mode damping analysis. Before joining Quanta
Technology, Tony worked as a
Graduate Research Assistant
at Rensselaer Polytechnic
Institute, where he worked with
utility companies to develop
new power systems software applications and computation methods.
Tony recently earned his PhD. in Electrical Engineering from Rensselaer Polytechnic Institute in Troy, NY.
Kathleen (Dalpe) Alcombright,
PMP, LEAN Six Sigma Green
Belt, Senior Advisor, Asset
Management, has over 12
years of energy industry experience in Program and Project
Management. Kathleen successfully led the multi-million
dollar Smart Grid Investment
Grant project with the New
York Independent System Operator, Inc. (NYISO) and New
York Transmission Owners
over the last four years, which focused on implementing synchrophasor technology including smart grid applications, infrastructure, data
analysis/storage and the communications network.
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If you would like to receive your copy, please
contact Lisa Williams at (919) 334-3071 or
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RECENT & UPCO M ING CO NFER ENCES
October 12-15
IEEE Innovative Smart Grid Technologies (Istanbul, Turkey)
October 19-21
Grid of the Future (Houston, TX)
October 22-23
February 3-5
February 17-20
North American Synchrophasor Initiative (Houston, TX)
IEEE PES Conference of ISGT (Washington, DC)
DistribuTECH (San Diego, CA)
ABOUT QUANTA TECHNOLOGY
Quanta Technology is an expertise-based, independent consulting company providing business and technical
expertise to the energy and utility industries for deploying holistic and practical solutions that result in improved
performance. Quanta Technology has grown to a client base of over 100 companies with an exceptional staff, many
of whom are foremost industry experts for serving client needs.
We are a subsidiary of Quanta Services, Inc., headquartered in Houston, TX, (NYSE: PWR), member of the S&P 500,
with 2012 revenue of $5.9 billion. The company is the largest specialty engineering constructor in North America,
serving energy companies and communication utilities, according to McGraw Hill's ECN. More information is available
at www.quantaservices.com.
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