Guidelines for the procurement and testing of STATCOMS

663
Guidelines for the procurement and testing of
STATCOMS
Working Group
B4.53
August 2016

GUIDELINES FOR THE
PROCUREMENT AND TESTING
OF STATCOMS
WG B4.53
Members
Dan Kell, Convenor (CA)
Regular Members
Georg Pilz (DE), Tony Siebert (US), Fernando Issouribehere (AR), Araud Galtier (FR),
Steven Murray (IE), Xu Shukai (CN), John Gleadow (NZ), Thomas Magg (SA), Marcio Oliveira (SE),
Juha Turunen (FI), Willie Otto (NZ) , Ricardo Tenorio (BR)
Corresponding Members
Gabriel Olguín (CL), Behdad Biglar (CA), Marta Molinas (NO), Murray Bennett (CA)
Copyright © 2016
“All rights to this Technical Brochure are retained by CIGRE. It is strictly prohibited to reproduce or provide this publication
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publication may be reproduced or utilized without permission from CIGRE”.
Disclaimer notice
“CIGRE gives no warranty or assurance about the contents of this publication, nor does it accept any responsibility, as to the
accuracy or exhaustiveness of the information. All implied warranties and conditions are excluded to the maximum extent
permitted by law”.
ISBN: 978-2-85873-366-8

Page iii
Guidelines for The
PROCUREMENT AND
TESTING OF STATCOMSW G B 4 - 5 3
Table of Contents
GLOSSARY OF ABBREVIATIONS AND SPECIAL TERMS...........................................................VII
1 INTRODUCTION.......................................................................................................................... 0
1.1 Background.............................................................................................................................. 0
1.2 Technical Brochure (TB) Scope............................................................................................... 0
2 SHUNT REACTIVE POWER COMPENSATION ......................................................................... 1
2.1 Basic operating principle.......................................................................................................... 1
2.1.1 SVC..................................................................................................................................... 1
2.1.2 STATCOM........................................................................................................................... 4
2.2 Advantages/Disadvantages of STATCOMs............................................................................. 8
2.3 References ............................................................................................................................ 10
3 STAGES LEADING TO DEVELOPMENT OF SPECIFICATION OF STATCOM...................... 11
3.1 Planning Specification ........................................................................................................... 11
3.1.1 Studies .............................................................................................................................. 11
3.1.2 Information to be Included in the Planning Specification .................................................. 12
3.1.3 Connection Requirements................................................................................................. 16
3.2 Feasibility Studies.................................................................................................................. 18
3.2.1 Layout ............................................................................................................................... 18
3.2.2 Interface to the ac system................................................................................................. 19
3.2.3 Auxiliary AC supply ........................................................................................................... 19
3.2.4 Audible noise..................................................................................................................... 19
3.2.5 Losses............................................................................................................................... 20
3.2.6 Other Items ....................................................................................................................... 20
3.3 Internal Procurement Team ................................................................................................... 20
3.3.1 Network Planning/System Development........................................................................... 20
3.3.2 Technical Design............................................................................................................... 21
3.3.3 Engineering Design........................................................................................................... 21
3.3.4 Network Operations .......................................................................................................... 22
3.3.5 Project Management......................................................................................................... 22
3.3.6 Finance and Legal............................................................................................................. 22
3.3.7 Asset Management ........................................................................................................... 23
3.4 Data/Requirements after Planning Specification ................................................................... 23

Page iv
3.4.1 Site and environmental conditions .................................................................................... 23
3.4.2 General design requirements............................................................................................ 24
3.4.3 Primary plant equipment requirements ............................................................................. 24
3.4.4 Control, protection and monitoring system requirements.................................................. 25
3.4.5 Auxiliary systems requirements ........................................................................................ 25
3.4.6 Other requirements ........................................................................................................... 26
3.4.7 Civil and building works requirements............................................................................... 26
3.4.8 Spares, special tools and maintenance requirements ...................................................... 26
3.4.9 Safety, health and environmental requirements................................................................ 26
3.4.10 Training requirements..................................................................................................... 27
3.4.11 Site Security.................................................................................................................... 27
3.4.12 Interference Requirements ............................................................................................. 27
3.5 Scope of Work ....................................................................................................................... 41
3.6 EPC Vs EP ............................................................................................................................ 43
4 TECHNICAL SPECIFICATION .................................................................................................. 45
4.1 Preliminary Specification/RFI................................................................................................. 45
4.2 Performance vs Equipment Specification .............................................................................. 45
4.3 ................................................................................................................................................... 45
4.2.1 Contents............................................................................................................................ 46
4.3 Form of Tender ...................................................................................................................... 49
4.3.1 General STATCOM........................................................................................................... 49
5 EVALUATION OF BIDS............................................................................................................. 53
5.1 Technical Evaluation.............................................................................................................. 53
5.2 Technical Evaluation – Ranking System................................................................................ 55
5.3 Evaluation of Bid Documents................................................................................................. 59
5.4 Environmental Evaluation ...................................................................................................... 59
5.5 Q/A with Bidders .................................................................................................................... 60
6 PROJECT IMPLEMENTATION ................................................................................................. 61
6.1 Kick-Off Meeting .................................................................................................................... 61
6.2 Design Review Process......................................................................................................... 61
6.2.1 Purpose............................................................................................................................. 61
6.2.2 Process and Planning ....................................................................................................... 61
6.2.3 Scope of Design Review................................................................................................... 62
6.3 Component Specification....................................................................................................... 64
6.4 Testing ................................................................................................................................... 66
6.4.1 Valves ............................................................................................................................... 66
6.4.2 Power Transformers.......................................................................................................... 66
6.4.3 DC Capacitors................................................................................................................... 67
6.4.4 Phase Reactors................................................................................................................. 67
6.4.5 Other Type Tests .............................................................................................................. 67
6.5 Control and Protection Factory Acceptance Tests................................................................. 67
6.6 Pre-commissioning and subsystem tests............................................................................... 67
6.7 Commissioning tests.............................................................................................................. 69
6.8 System tests .......................................................................................................................... 70
6.8.1 Startup and shutdown test ................................................................................................ 71

Page v
6.8.2 Constant reactive power control test................................................................................. 71
6.8.3 Voltage control mode test ................................................................................................. 71
6.8.4 Dynamic performance test ................................................................................................ 72
6.8.5 STATCOM operating range test........................................................................................ 72
6.8.6 STATCOM redundancy test.............................................................................................. 72
6.8.7 STATCOM overload test................................................................................................... 72
6.8.8 AC system fault test .......................................................................................................... 73
6.8.9 STATCOM control under Power Dispatching Center........................................................ 73
6.8.10 Trial Operation................................................................................................................ 73
6.9 Training.................................................................................................................................. 73
6.10 Computer Models ................................................................................................................ 75
7 PROJECT CLOSE ..................................................................................................................... 76
7.1 Punch List .............................................................................................................................. 76
7.2 Documentation....................................................................................................................... 77
7.2.1 STATCOM simulation models........................................................................................... 78
7.2.2 STATCOM Simulation Models References....................................................................... 85
7.3 Spare parts strategy/Obsolescence Management................................................................. 85
7.4 Monitoring of Performance .................................................................................................... 86
7.5 After-market Support ............................................................................................................. 86
7.6 Maintenance .......................................................................................................................... 87
8 LESSONS LEARNED................................................................................................................ 88

Page vii
GLOSSARY OF ABBREVIATIONS AND SPECIAL TERMS
The table below lists the abbreviations used throughout this brochure.
Abbreviation Full Text
CPF Cumulative Probability Function
DC Direct Current
EMC electromagnetic compatibility
EMF Electromagnetic Fields
EPC Engineer, Procure and Construct
EP Engineer, Procure
FAT Factory Acceptance Tests
HMI Human Machine Interface
I/O Input/Output
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronic Engineers
IGBT insulated-gate bipolar transistor
IGCT integrated gate-commutated thyristor
MSC Mechanically switched capacitor
MSR Mechanically switched reactors
MVAr Mega Volt-ampere reactive
OEM Original equipment manufacturer
PCBs polychlorinated biphenyls
PCC Point of Common Coupling
Plt long term flicker severity
Pst short term flicker severity
RAM reliability, availability and maintainability
RFI Request For Information
RI Radio and Television Interface
SCADA Supervisory control and Data Acquisition
STATCOM static synchronous compensator
SVC Static Var Compensator
SVS Static Var System
T Tesla
TCR Thyristor controlled reactors
TSC Thyristor switched capacitors
TSR Thyristor switched reactors
UIE International Union for Electricity Applications
VSC Voltage Sourced Converter
WG Working Group
ZS(h) system impedance

1 INTRODUCTION
1.1 Background
A static synchronous compensator (STATCOM) is a reactive power regulating device based on the
voltage sourced converter (VSC) used to maintain ac system voltages and enhance the stability of the ac
system. As these power electronic devices are becoming more and more prevalent in the power-system,
it is becoming more important than ever to have a set of guidelines in place to enable the industry to
adequately procure and test these devices to ensure safe, efficient and reliable operation, while
maintaining the capability to allow the “future-proofing” of the system for future upgrades.
1.2 Technical Brochure (TB) Scope
This TB’s scope is to gather the knowledge of technical people concerning the procurement and testing
of STATCOMs and produce a report that will allow the planners/engineers of the utility to specify and test
the STATCOM such that it will offer safe, efficient and reliable operation. This WG plans to incorporate
the best practices as determined by a panel of experts which will include representatives from utilities
with STATCOMs presently in operation in their system, manufacturers of STATCOMs and consultants.
Chapter 2 begins with an overview of shunt reactive power compensation techniques and discusses the
main types of reactive compensation available (SVC and STATCOM). The chapter then discusses the
major components of each device and the advantages/disadvantages of a STATCOM.
Chapter 3 focuses on the stages leading to the development of the planning specification for the
STATCOM. The chapter starts by discussing the inputs required for the development of the planning
specification. It also compares the various types of specifications and guides the reader through the pros
and cons.
Chapter 4 builds on Chapter 3 and develops the technical specification from the planning specification.
This looks at whether one should develop an equipment specification or a performance specification and
develops items such as the form of tender, list of required tests, drawings, etc.
Chapter 5 discusses how to evaluate the bids submitted by the various vendors using a clear set of
evaluation criteria and process.
Chapter 6 looks at, after selecting the successful bidder, how to implement the projet and the various
stages involved. It also discusses the various tests that need to be applied, specifically in regards to the
valves and on-site testing.
Chapter 7 discusses the closure of the project and how to transition from the construct/testing phase into
commercial operation
Finally chapter 8 attempts to summarize some lessons learned from the various contributors to this
working group, based on their experiences.

2 SHUNT REACTIVE POWER COMPENSATION
This chapter briefly presents the basic operating principles of shunt connected reactive power
compensators which are based on the utilization of semiconductor components.
It also compares the operation of SVC versus STATCOMs to allow one to decide what
technology is the most suitable. For more detailed information of each technology please refer
to CIGRÉ publications, SC 38 WG 38.05.04 Analysis and optimisation of SVC use in
transmission systems and SC 14 WG 14.19 Static synchronous compensator (STATCOM).
2.1 Basic operating principle
The basic operating principle of shunt connected reactive power compensators is shown in
Figure 2.1. It contains a power supply which supplies current isup, a reactive power compensator
which draws current icomp and a feeder for a load which draws current iload.
Figure 2.1 Example of Shunt compensation operating principle.
The basic purpose of the reactive power compensator is to provide dynamic reactive support in
order to help control the voltage at the connection point.
2.1.1 SVC
This chapter briefly describes Static Var Compensators (SVCs), typical applications in power
systems and the components they are comprised of.
SVCs are shunt connected static generators/absorbers of reactive power whose outputs are
varied so as to maintain or control specific parameters (ac voltage, reactive power) of the
electric power system. The term ‘static’ is used to indicate that SVCs, unlike synchronous
compensators, have no moving or rotating main components. Thus SVCs consist of static var
generator and/or absorber devices capable of drawing capacitive and/or inductive current from
an electrical system, and a suitable control device. A static var system (SVS) is defined as a
combination of different static and mechanically switched var compensators whose outputs are
coordinated [1].
By generating or absorbing reactive power in a power system, SVCs are used to control system
voltages. As the output of the SVC can be varied relatively fast, SVCs can be used as dynamic
compensation devices.
2.1.1.1 Typical applications in power systems
isup
icomp
iload
Comp

SVCs with particular characteristics and controls are applied to power systems to solve a variety
of problems, namely:
a) to achieve effective voltage control
b) to provide/absorb reactive power
c) to increase the active power transfer capacity of both existing and new transmission
systems
d) to increase transient stability margins
e) to increase dynamic reactive reserve margins
f) to improve fault recovery
g) to reduce temporary overvoltages
h) to facilitate integration of renewable generation
i) to increase damping of power oscillations
j) to damp subsynchronous oscillations
k) to balance voltages (load balancing) of individual phases i.e. asymmetrical loads
l) to provide flicker mitigation
m)
In some of these applications, in order to achieve the desired control, the reactive power can be
varied slowly using mechanical switching of shunt reactors and capacitors, while in others fast
variation is required which can be achieved by static var compensators.
2.1.1.2 Components of SVCs
SVCs can be comprised of the following components, typically connected through a power
transformer:
a) Mechanically Switched Capacitors and Reactors (MSC and MSR).
b) Saturable reactors.
c) Thyristor Controlled reactors (TCR).
d) Thyristor Switched Reactors (TSR).
e) Thyristor Switched Capacitors (TSC).
f) Capacitor harmonic filter banks.
The above combination of devices can be used alone or in combination depending on whether
slow (MSC, MSR, saturated reactor) or fast varying (TCR, TSC, TSR) compensation is required,

and whether stepwise (switched solution) or continuous control (TCR and filter) of reactive
power is required. The speed and type of compensation required will depend on the particular
power system application.
Saturated
Reactor
TCR & TSRMSR MSC TSC Filter
Figure 2.2 Basic components of SVC’s.
Figure 2.3 Operating characteristic for an SVC.
Mechanically switched capacitors and reactors provide slow step-wise control of reactive power
due to circuit-breaker operating time. Thyristor controlled reactors (TCRs) consist of a reactor/s
in series with a bidirectional pair of thyristor valves. Continuously variable fast control of
inductive reactive power is possible with TCRs. The switching actions of TCRs produce
harmonics which need to be filtered by capacitor harmonic filter banks which also normally
provide capacitive reactive power. Thyristor switched capacitors (TSCs) consist of a capacitor
in series with a bidirectional thyristor pair and a small reactor. TSCs can be used for fast
stepwise control of capacitive reactive power. Thyristor controlled or switched devices are
usually connected to a high voltage system via a step-down transformer.

2.1.2 STATCOM
The basic components of the STATCOM are presented in Figure 2.4. As is shown in the figure,
generally a STATCOM consists of a Voltage Source Converter (VSC), which is connected to a
point of coupling. A DC-capacitor is connected on the DC-side of the VSC.
ucomp
icomp
usup
Figure 2.4 STATCOM.
The purpose of the VSC is to produce a desired output voltage ucomp. Since the compensator
current icomp is dependent on the voltage difference between the supply voltage usup and
compensator voltage ucomp in addition to the phase reactance, the compensation current icomp
can be controlled as desired by controlling the VSC output voltage ucomp.
For more details on the layout and operation of a STATCOM, please refer to TB 144 1999 SC
14 WG 14.19 Static synchronous compensator (STATCOM).
2.1.2.1 Typical applications in power systems
STATCOMs with particular characteristics and controls are applied to power systems in order to
solve a variety of problems, namely:
a) to achieve effective voltage control
b) to provide/absorb dynamic reactive power support
c) to increase the active power transfer capacity of both existing and new transmission
systems
d) to increase transient stability margins
e) to increase dynamic reactive reserve margins
f) to improve fault recovery
g) to reduce temporary overvoltages
h) to facilitate integration of renewable generation
i) to increase damping of power oscillations

j) to damp subsynchronous oscillations
k) to balance voltages (load balancing) of individual phases i.e. asymmetrical loads
l) to provide flicker mitigation
m) to provide active filtering
The following sections describe some of the more typical applications of the STATCOM
2.1.2.2 Reactive power compensation
The first category of applications where STATCOMs are used is reactive power compensation
and dynamic voltage regulation at fundamental frequency. In this type of application the
STATCOM runs in steady-state operation with almost constant output for most of the time.
The most common use for a STATCOM is for voltage regulation. In the cases where the supply
network is weak, i.e. it’s short-circuit level is relatively low, the changes in reactive power taken
by the load result in variations or even dips in the voltage of the supply network. These reactive
power changes may be initiated by the switching of electric grid components such as capacitor
banks. Another reason for voltage variation are faults in the supply network. In these cases the
voltage dips may be mitigated and the supply voltage supported by rapidly injecting reactive
power to the network using the STATCOM.
In this category the device could also be called a “utility STATCOM” because its ultimate
purpose is to regulate the voltage of the supply network by controlling the reactive power flow.
These kinds of STATCOMs may be used in weak power networks, where variable renewable
generation, such as wind farms are connected. Especially, in the case of wind farm applications
it is important to avoid voltage disturbances because of the sensitivity of wind turbines and so
utilities usually require fault ride through capability for wind turbines.
2.1.2.3 Active filtering
STATCOMs can also be used for active filtering application. These kinds of STATCOMs have
continuously changing output which includes harmonic frequencies in addition to fundamental.
The basic task in this category is harmonic filtering. The purpose of the STATCOM is to produce
harmonic current components with the same amplitude and opposite phase as are present in
the current taken by the load. The harmonic current components are reduced at the point of
coupling, therefore resulting in sinusoidal current taken from the supply network. This is a
function provided by the STATCOM, since there are a variety of loads which are producing
harmonics to the supply, such as adjustable speed drives, welding machines and arc furnaces.
2.1.2.4 Current Balancing/Flicker Mitigation
Another task accomplished by the STATCOM is current balancing. Some loads, such as single-
phase loads and loads connected between two phases draw unsymmetrical currents from the

supply, i.e. their three-phase currents are not equal in amplitude and the difference between
phase angles is not 120°. Also three-phase loads, such as arc or ladle furnaces, may draw
unsymmetrical currents. In these cases the currents can be balanced using the STATCOM,
which is able to control the phase currents individually.
Some loads, such as welding machines or rolling mills are also sources of flicker. Flicker is a
phenomenon present in the supply network as it can be sensed as an annoying flickering of
lights. The origins of flicker are voltage dips, which are generated because of the finite supply
network impedance and the current peaks drawn by the source of flicker. These voltage dips
can be mitigated using the STATCOM in the same manner as is done in the case of voltage
regulation. Please refer to TB 237 2003 SC B4 WG B4.19 Static synchronous compensator
(STATCOM) for arc furnace and flicker compensation.
2.1.2.5 Power Oscillation Damping
A STATCOM can provide power oscillation damping and help maintain system stability. After
detailed studies have been completed to determine the most suitable location and
measurement points for the STATCOM and the damping controls developed, the STATCOM
can improve system stability and increase real power transfer.
2.1.2.6 Energy Storage
A STATCOM can also inject/absorb active power into/from a network if combined with an
energy storage device can also act as an energy storage device. Some power quality
enhancement tasks may be done more efficiently, if the STATCOM is able to control both active
and reactive powers. However, it is not possible for the STATCOM to output continuous active
power unless some kind of energy storage device is connected to its DC-side.
In this case if active power is needed in the ac network, the STATCOM can produce it by taking
energy from the storage device on the DC-side and converting it to the ac-side. Similarly, the
direction of the active power flow can also be from the ac-side to the DC-side, therefore the
STATCOM is able to reload energy to the energy storage device from the ac-network. However,
currently the energy capacity of the storage devices available is rather small compared to
energies required by the power network: therefore the STATCOM can only provide short-term
active power support.
Typical applications where the use of an energy storage device with the STATCOM is
advantageous are related to supply network security or angular stability: compensation of
voltage sags, damping of power system oscillations, flicker reduction etc. These are needed
especially in weak networks where plenty of renewable energy sources are installed.
Basically the energy storage device can be any equipment used for short-term electric energy
storage such as a flywheel or battery. In the future, fuel cells or superconducting magnets may
also be used for this purpose.
Please note the type of STATCOM topology used may limit the capability to provide energy
storage.

2.1.2.7 Components of a STATCOM
STATCOMs can be comprised of the following components:
a) Voltage Sourced Converter
b) Coupling transformer and/or phase reactors
c) Capacitors and/or Reactors banks (fixed or switched)
d) Filter bank (if required)
The core of a STATCOM is the Voltage Sourced Converter. The main components are one or
more DC capacitors and number of forced-commutated power electronic switches. The task of
the switches is to connect the DC voltage of the capacitor to the terminals of the Voltage
Sourced Converter and to form a nearly sinusoidal voltage waveform. Examples of different
types of topologies are shown in Figure 2.5. The Voltage Sourced Converter provides
continuous high speed reactive power capability as shown in Figure 2.7. To extend the
operating range of the Voltage Sourced Converter a fixed or switched capacitor/reactor bank
can be connected. Independent of the response time of the STATCOM the switched solution
can be based on mechanical switched breakers (slower response time) or power electronic
switches like a thyristor (faster response time). To fulfill the Grid Code connection criteria
regarding harmonic performance a capacitive filter in parallel to the Voltage Sourced Converter
may be necessary. Please note the type of STATCOM topology may have a decisive impact
regarding harmonic performance of the converter. A transformer or/and an additional reactor
may be necessary in the Voltage Sourced Converter path to connect the network which can
assist in harmonic performance.
+
-
+
-
0
Modul #1
Modul #2
Modul #3
Modul #4
Modul #8
Modul #7
Modul #6
Modul #5
+
-
Figure 2.5 Topologies of Voltage Sourced Converters (Courtesy of Siemens)

Figure 2.6 Basic components of a STATCOM
Figure 2.7 Operating characteristic for an STATCOM
2.2 Advantages/Disadvantages of STATCOMs
This brochure’s ultimate goal is to help the reader develop a specification for the procurement of
a STATCOM. The preceding chapters gave a high overview of the two types of static
compensation. In order to determine what type of device is required, detailed studies are
required and will be discussed later.
When looking at what type of shunt device to use (whether it be a STATCOM, SVC or even a
shunt capacitor), one needs to consider steady-state and dynamic performance requirements in
order to achieve a solution with best cost-benefit ratio.
The main advantage of the STATCOM over the SVC is the ability to provide rated capacitive
reactive current when the voltage is low, compared to an ordinary SVC, which once the voltage
is low, behaves as fixed device whose output current varies with the square of the voltage. The
STATCOM also has a faster response as it has almost no time delay associated with firing.

As the STATCOM typically does not require filters or additional shunt banks, the overall footprint
is smaller in STATCOM systems, taking up approximately 30%-40% the area of a similarly rated SVC.
The main drawbacks when comparing a STATCOM against an SVC would foremost be the
cost, with the STATCOM typically costing about 15% to 20% more for similiar ratings. Of
course, cost will also be dependent of several factors outside the main components; civil,
available footprint, losses, noise, etc.
The capacitive/inductive output of a STATCOM is symmetrical unless combined with another
compensation device. By providing fixed reactive compensation and harmonic filters an SVC
can be designed to have different capacitive/inductive outputs.
One other drawback would be the inherent overload of the STATCOM compared to the SVC.
This is because typical STATCOM IGBT devices do not have the same inherent overload
capacity as Thyristors and so any excess capacity must be designed into the STATCOM valve
as explained below.
In an SVC TCR valve the design is made so that the thyristors are running at a maximum
allowed temperature at maximum steady state system voltage. A margin to destructive
temperatures is reserved in order to handle fault cases, which can be substatial.
In a STATCOM, the maximum output current is given by the difference in the voltage between
the converter terminal voltage and the power system voltage. A typical design for the converter
will allow for a maximum current corresponding to about 10–15% voltage difference across the
phase reactance. Accordingly the control system must ensure that the converter terminal
voltage is kept high enough not to overload the plant. At full current (rated power) the converter
semiconductors, work at their maximum allowed steady state temperature. A margin to
destructive temperature must be left for uncertainties and for fault cases. There is also a
maximum instantaneous current that the semiconductors can turn off. The same principle is
used here; a margin must be left for uncertainties and for fault cases. The design outcome is
that a STATCOM does not have short time overload capacity unless its power rating is de-rated
initially. Using the above mentioned margins for planned short time operation would jeopardize
the plant security.
It should be mentioned that STATCOMs and SVCs can be combined to form a hybrid dynamic compensation
device.

2.3 References
[1] CIGRE Working Group 38-01, “Static var compensators”. CIGRE Brochure No. 25, 1986.
[2] CIGRE Technical Brochure No 269, VSC Transmission. CIGRE WG B4.37, 2005.
[3] CIGRE Technical Brochure No 492, Voltage Source Converter (VSC) HVDC for Power
Transmission – Economic Aspects and Comparison with other AC and DC Technologies.
CIGRE Working Group B4.46, 2012.
[4] Gustafsson, A., Saltzer, M., Farkas, A., Ghorbani, H., Quist, T., Jeroense, M. The new
525 kV extruded HVDC cable system. ABB Grid Systems, Technical Paper Aug 2014.
[5] Mahimkar, N., Persson, G., Westerlind, C. HVDC Technology for Large Scale Offshore
Wind Connections. Proc. of Smartelec 2013, Vadodara, India, April, 2013, 5 pp.
[6] Callavik, E. M., Lundberg, P., Bahrman, M. P., Rosenqvist, R. P. HVDC technologies for
the future onshore and offshore grid. Proc. of CIGRE Symposium “Grid of the future”,
Kansas City, USA, October, 2012, 6 pp.
[7] Y. Phulpin, "Communication-Free Inertia and Frequency Control of Wind Gen Erators
connected by an HVDC-Link", IEEE Transactions on Sustainable Energy, 27(2), May
2012, pp. 1136-1137.
[8] T. Haileselassie, "Control, Dynamics and operation of Multi-terminal VSC-HVDC
Transmission Systems", Ph.D. Thesis, NTNU Trondheim, Norway, 2012.
[9] R. Sharma, "Electrical Structure of Future Off-Shore Wind Power Plants with a High-
Voltage Direct Current Power Transmission", Ph.D. Thesis, Technical University of
Denmark, Lyngby, 2011.
[10] Offshore Grid Development Plan 2013, first draft. German TSOs. 2013.
http://www.netzentwicklungsplan.de/content/offshore-netzentwicklungsplan-2013-erster-
entwurf
[11] CIGRE WG B3-36 report, "Special considerations for AC collector systems and
substations associated with HVDC connected wind power plants".

3 STAGES LEADING TO DEVELOPMENT OF SPECIFICATION OF STATCOM
This section deals with the various stages involved in developing a specification for a
STATCOM. These stages may include the following:
• Planning Specification
• Feasibility studies
• Internal Procurement
• Data Requirements
• Scope of Work
It should be mentioned that these stages are typically used to define the requirements for the
reactive power device and may show that an SVC, synchronous condensers or switched
devices may give a better technical and economic solutions than a STATCOM for specific
applications. In saying this, this document focuses on the procurement of a STATCOM. The
stages listed above are defined below.
3.1 Planning Specification
The planning specification is a high level document defining the main functional and
performance requirements of the STATCOM. This document also provides system information
that enables manufacturers to design the STATCOM. The planning specification is typically
developed once the need for the reactive device has been determined. In this chapter a list of
items that should be addressed in the planning specification is presented.
3.1.1 Studies
The studies required to create the planning studies are usually carried out by the utility planning
group or consultant and a typical scope of the studies are:
• Steady-state loadflow analysis
• Short-circuit analysis
• Steady-state voltage analysis
• Dynamic analysis
• Step change voltage analysis
• Voltage stability margin analysis (using PV or QV curve)
• Load rejection analysis
Some more detailed studies that may be required after the above studies have been completed
include:
• Harmonic analysis
• Voltage phase unbalance analysis
• Voltage flicker analysis
• Overload/Overvoltage studies
• Secondary voltage range
From this type of analysis the general area requiring the STATCOM (i.e. location of required
voltage stability support) will be established.
The planning group will be required to run some kind of comparative analysis in order to find an
optimum location (nodal location, voltage level) for the required dynamic reactive power device.

This analysis should take account of future system requirements such as the changing location
of critical generating plant as well as new sources of generation (wind, solar etc.) and their
unique characteristics.
This group will also be required to develop the base case model and define the critical
contingencies that will determine the need for the STATCOM to be provided to the Vendors with
the tender documents.
At this stage the choice of a STATCOM, SVC or other dynamic compensation device may not
have been made, but the need for some type of dynamic reactive power control device will be
established.
3.1.2 Information to be Included in the Planning Specification
The following information should be included in the planning specification:
3.1.2.1 General overview and background information
An overview of the project explains the nature of the problem and outlines what is expected
from the STATCOM. Normally in this section of the planning specification, suitable future
location or locations of the STATCOM are given.
Environmental data should also be given since some of them are decisive for the design and
may impact costs, e.g. sensitive seismic zones, very high or low ambient temperatures and
extremely high pollution levels.
It is very important to consider the existence of other dynamic reactive power devices (e.g. other
FACTS devices, synchronous generators/compensators etc) electrically close to the STATCOM
to be installed to determine if any possible interactions may exist.
3.1.2.2 System characteristics
- The following system characteristics at the point of connection should clearly be
identified. These will define the following:
- The conditions for which the STATCOM will be required to meet the performance
requirements
The most onerous conditions are for which the STATCOM equipment must be rated to survive
without damage or tripping.
If operation occurs outside of the specified conditions, the STATCOM may be allowed to trip.
Supply voltage:
- Nominal, minimum, and maximum continuous voltages
- Temporary over-voltage and short term under-voltage levels and durations
- Voltage unbalance
- Basic insulation level
- Low voltage ride through capability

Supply frequency:
- Nominal, minimum, and maximum frequencies levels and durations
- Maximum rate of change of frequency (Hz/Sec)
Fault level:
- Minimum and maximum performance fault levels (single and three phase)
- Specific Equipment design fault levels
- X/R ratios
- Fault clearing time and characteristics (main and backup, auto-reclose, etc.)
Harmonics:
- Harmonic performance requirements, including applicable standards
At this stage, the following could also be determined, but is not required at this stage. The only
reason to include this now is the timeframe required to perform this work and it is a good idea to
start it early. More details can be found in section 3.4.12.
- Existing network harmonic levels (background harmonics)
- Network harmonic impedances seen from the STATCOM connection point
3.1.2.3 STATCOM continuous and short-term rating
The planning specification shall specify the reactive power output of the STATCOM, and clearly
indicate the voltage and the operating points this rating must be guaranteed. It should also
specify the required short-term rating or overload cycle of the STATCOM if required. Moreover,
Owners should provide reasoning for short-term rating requirement.
3.1.2.4 Losses
The planning specification should provide a typical operating profile (e.g. 80% at 5MVAr, 20% at
20MVAr) and $/kW figure for loss evaluation purposes. However, this figure must be
accompanied by the most common mode or modes of operation and expected duration at each
operating point/region. This way, the manufacturer would be able to offer a cost effective
design. Figure 3.1 depicts a generic loss curves of a small STATCOM. As shown in this figure,
impact of transformer load-losses at zero MVAR output is insignificant. On the contrary, it
appears load-losses can have a meaningful impact at full output.

Figure 3.1 Typical STATCOM loss vs. reactive power output curves
3.1.2.5 Reliability, Availability and Maintainability (RAM)
The planning specification should specify the reliability, availability and maintainability (RAM) of
the STATCOM. Unfortunately it is often difficult to define a RAM figure that correctly reflects the
importance of the STATCOM to the network without over-emphasizing. Requesting high RAM
figures will impact the price greatly and the Owner must pay careful attention when specifying
this figure. It is prudent to first investigate inherent RAM figures for a typical STATCOM with
similar rating. If the target is quite high, a high degree of redundancy will be required and in the
worst case multiple STATCOMs become the optimal solution depending on partial availiability
may be required. It should be pointed out that use of multiple STATCOMs not necessarily imply
on higher reliability of the plant.
Talking to other owners of STATCOMs can also help greatly in determining what to specify.
An availability of 98% is inherently achievable for a STATCOM. If a higher availability is
required, further engineering of the STATCOM (and associated costs) will be required.
Typical number of forced outages for SVC and STATCOM in transmission system applications
is 2-3 stops per year. Higher reliability will require hot standby equipment/branches.
The vendor should also provide the basis for the calculations of their RAM figures and specify
the spare parts included in their quotation.
The STATCOM Vendor should also recommend a maintenance plan to be followed by the
Owner so that the calculated and expected RAM figures can be achieved after finalization of the
project.
0
-100 -80 -60 -40 -20 0 20 40 60 80 100
Load Factor [%]
Losses[%]
STATCOM losses Without Transformer
STATCOM losses With Transformer
Capacitive
Inductive

It is normal for utilities to request a guarantee on the RAM requirements for a few years after the
commercial in-service date. In this case, after the grace period when all the first energization
issues are resolved, the Owner will monitor the RAM of the STATCOM and if the STATCOM
does not meet the guaranteed RAM, the Owner may extend the guarantee period (moving
window) or receive financial compensation.
The reader is encouraged to review IEEE 493 - Recommended Practice for the Design of
Reliable Industrial and Commercial Power Systems for more details.
3.1.2.6 Control system
The planning specification shall specify the required control modes of the STATCOM. Typical
control modes are as follows:
- Voltage Control Mode: It is a closed loop controlling function which maintains the voltage
at the point of connection near an adjustable reference voltage set by the operator. The
specification shall define the upper and lower limits and also the adjusting increment (e.g.
voltage control in small steps). It shall also specify the minimum and maximum limits and
adjusting increment for the slope/droop. Normally in the voltage control mode, the
controller controls all three phases equally. However, for systems with large unbalanced
voltage, the Owner can specify a single phase voltage controller. This function allows the
STATCOM to control each phase of the convertor independently, reducing/mitigating the
voltage unbalance condition. Planning specification should clearly indicate whether a
single phase voltage controller is required.
- Q Control Mode; This mode will allow one to set the reactive power output of the
STATCOM to a predetermined MVAr level.
- Adjustable Q (reserving Q): In this mode, the STATCOM is controlled by two closed loop
controllers. One loop has a smaller time constant, which operates like a voltage regulator
and only responds to sudden voltage transients in the system. The reference voltage for
this closed loop is the same as the system steady-state voltage prior to the transient. The
other loop has a much longer time constant which slowly, after the transients have
subsided, brings the STATCOM output to a predetermined MVAR output (reference Q).
Normally the Q is set in order to reserve the STATCOM’s maximum capacity for
responding to voltage transients. When specifying this mode, the Owner shall determine
the upper and lower limits and adjusting increments for Q reference. Requesting
adjustable time constant for the slow control loop is also beneficial. Care must be taken
when operating in this mode to ensure that the STATCOM does not take the ac system
to its voltage limits.
These control modes are for the STATCOM control only and there may be a requirement for the
STATCOM to be integrated into an overall reactive power management scheme.
3.1.2.6.1 Supplementary Controls
STATCOMs can also be equipped with supplementary controls to help stabilize the power
system. These controls can look at the ac bus voltage, powerflow on a specific line, etc.
Detailed studies will be required in order to develop and tune the supplementary controller.

3.1.2.6.2 Human Machine Interface
Planning specification should clearly determine the parameters that can be enabled or disabled,
set, and monitored from remote terminals and/or the dispatch centre. The following parameters
are normally required to be enabled/disabled and adjusted on the remote terminal(s):
• Activation of various modes
• Set points. Access must be restricted for some set points, e.g. slope, time constants,
etc., by means of Engineering password
• Monitoring of system voltage, branch currents and reactive power
• Start- and stop-sequences
• Alarms list and status
• Emergency trip
Any remote access to fault recorders and alarm list/statuses should be defined here.
3.1.2.6.3 Redundancy
Depending on the importance of the system and maintenance requirements that the STATCOM
is connected to, the planning specification should identify whether required redundant
equipment (main circuit, auxiliaries, control and protection) is needed, regardless of the
manufacturers RAM calculations.
3.1.2.6.4 STATCOM step response
The planning specification should specify the step response of the STATCOM by defining the
maximum acceptable response time, settling time, and overshoot. The planning specification
must clearly identify the system short circuit level that these parameters must be determined at.
To avoid future confusion it is recommended to use an already established definition of the
above-mentioned parameters such as the IEEE 1031”IEEE Guide for the functional
specification for Static Var Compensators.
3.1.3 Connection Requirements
It is beneficial to determine the connection requirements of the STATCOM in the planning
specification as some circuit breakers may not be in the scope of delivery of the STATCOM
vendor but are part of an existing switchgear.
Large STATCOMs connected to transmission substations can be connected to the system the
same way as a line is connected. For example in a breaker and a half scheme STATCOM’s
means of connection can be two breakers as shown in figure 3.2. In this case, a coordination

study must be carried out as any trip initiated by the STATCOM may result in tripping the other
line(s) connected to that bay.
To avoid complication, the Owner can request or provide a dedicated circuit breaker for the
STATCOM. In any case it is prudent to identify the method of switching at the planning stage
and plan ahead for coordination between the substation protection and STATCOM protection.
For a smaller STATCOM or DSTATCOM, it is possible to use a combination of a switch and
fuse. However, it must be noted that in the case of a single phase operation of fuse, the
coupling transformer will be energized by only two phases, and since the secondary of the
coupling transformers are mainly delta connected, the loss of one phase may not be reflected to
the low side of the transformer. It is prudent to inform the manufacturer, if a switch/ fuse is being
used for the STATCOM.
Figure 3.2 Examples of STATCOM connection types in transmission (top) and distribution systems
(bottom)

STATCOM
STATCOM
STATCOM

3.2 Feasibility Studies
In order to select a suitable location for the STATCOM (once the planning study has been
completed as shown in section 3.1) and to define the physical, electrical, performance and
environmental requirements in the STATCOM specification, a feasibility study should be carried
out in the early stage of the project. In this chapter, major items that need to be studied are
discussed. These items can be used as a check list to facilitate the feasibility study.
3.2.1 Layout
Size of the following items may be considered in the physical layout in order to estimate the
space requirements:
- Coupling transformer(s) and/or phase reactors (including spare if required)
- STATCOM (inverter) housing
- Filters
- Fixed capacitor banks, if applicable
- Cooling system
- Switchgear
- Metering (Instrument transformers)
- Auxiliary transformer(s)
- Services building (including control and protection room, battery room, cooling,
workshop, spares storage etc.)
- Access road to the station
- Maintenance access around the equipment
- Applicable clearances (magnetic, electrical and environmental)
The actual foot print mainly depends on the MVA rating, voltage level, utility standards, reliability
requirements and manufacturers’ technology. At this stage manufacturers can provide some
guidance on the expected layout and size. The required footprint of a 35Mvar Statcom can be
assumed with 60m x 37m, a 100Mvar STATCOM with 72m x 34m. Figure 3.3 shows a typical
STATCOM layout.
Figure 3.3 Typical +/-100 Mvar (courtesy ABB)

3.2.2 Interface to the ac system
The interface to the ac system needs to be considered as this will drive the following:
• Voltage level of STATCOM
• Connection to the ac system
• Communication/SCADA requirements
• Enabling working in existing substations (if applicable)
• Ground grid
• Lightning protection
• Insulation coordination
• Protection coordination
3.2.3 Auxiliary AC supply
It is important to know the approximate ac load of the STATCOM auxiliary equipment (such as
cooling pumps, fans, heating, air conditioning, lighting, etc.). Knowing the required load will help
to determine if any existing nearby station service transformers or a tap-off of a nearby
distribution are adequate.
If there is adequate extra capacity in a nearby station’s auxiliary ac supply, it is necessary to
specify the STATCOM’s ac auxiliary supply rated voltage in the specification to be the same as
station service rated voltage of the nearby station.
This should be optimized to consider the distance of the existing station service supply versus
providing local station services.
If the STATCOM is to be installed as part of a new station, then the new station service shall
need to be sized to accommodate the STATCOM.
The fault ride through capability of the auxiliaries and their normal and temporary voltage
variations must also be considered as this will determine the design basis for the auxiliaries.
The following provides some of the typical auxiliary loads for a STATCOM. Actual loading
depends on the manufacturers’ technology.
• Converter (Valve) Cooling
• Transformer cooling
• Heating and Cooling
• Protection and controls
• Station lighting
• DC battery chargers
• etc.
3.2.4 Audible noise

Audible noise emitted by STATCOM equipment needs to meet the local environmental laws. It
is prudent to first identify the noise requirements of the potential location(s). The Owner should
indicate their noise requirement in the STATCOM specification. The Owner should identify the
nearest point of receptions (the nearest residential or commercial buildings) along with
maximum allowable audible noise at that point (sound pressure). In some jurisdictions there is a
penalty for tonal (humming) noise, which may be caused by specific harmonics from the
STATCOM.
3.2.5 Losses
For a optimized design regarding losses the specification should be carefully interpreted
regarding the evaluation of the different operating ranges of the STATCOM (as recommended
in section 3.1.2.4).
The specification should provide a $/kW figure for loss evaluation purposes. However, this
figure must be accompanied by the most common mode or modes of operation and time at
operating point.
Losses should be considered at early stage as they may drive the justification and the design of
the STATCOM. The Owner must state how losses are considered at tender evaluation.
3.2.6 Other Items
Other items to be considered when selecting the locations are:
1. Accessibility
2. Location of nearby auxiliary power sources
3. Transportation limitations
3.3 Internal Procurement Team
When setting up the team in order to procure, specify and test a STATCOM installation, there
are typically seven distinct areas of responsibility required.
These are:
1. Network Planning/System Development
2. Technical Design
3. Engineering Design
4. Network Operations
5. Project Management
6. Finance & Legal
7. Asset Management
The role and responsibilities of each of these areas is explained in the following sections.
3.3.1 Network Planning/System Development

The network planning task is to perform the studies that first identify the need for the
STATCOM. These are likely to consist of power system security studies but are not likely to
extend to power quality or in depth technical performance studies. These technical performance
studies are more suitably performed by a specialized technical design group.
3.3.2 Technical Design
The technical design task will identify the choice of STATCOM technology as the appropriate
design solution to meet the functional and performance requirements. This may be from
knowledge of the market or through consultation with Owners who can advise on the cost of
appropriate offerings to meet the technical requirements through the development of a request
for information (RFI) or mini-draft specification.
This task will probably be required to produce the functional specification for the STATCOM and
to evaluate the allowed technical parameters of operation from a system performance
perspective. Grid Code compliance will also be a major concern of this group.
The output of the technical design task should also include a list of functional requirements that
will constitute the inputs for engineering design.
3.3.3 Engineering Design
The engineering design task will develop the equipment design and specification. Their
responsibility will be to translate functional design from Network Planning and Technical Design
areas (system needs plus performance parameters) into equipment design while taking account
of the following issues:
• Interface issues (electrical, communications, etc.)
• onstructionConstruction and commissioning
• Maintenance issues
• Required standards (IEC, IEEE, internal standards)
The engineering design group will review the data provided by the planning and technical group
and ensure that the new device can be successfully integrated into the ac system.
Engineering design will necessarily involve cross-over with operational planning in the
facilitation of outages to build and commission the STATCOM as well as the frequency and
duration of required maintenance schedules offered by varying technologies or Owners.
This group will also determine the additional spares and/or spare strategy that may be required
(in addition to any spares determined by the Vendors reliability calculations) and for long term
operation, potentially beyond the support time period of the existing controls, which tend to have
a shorter life than the main circuit equipment. In addition to this, this group will also determine
whether redundancy is required and where, irrespective of the Vendor’s Reliability, Availability
and Maintenance (RAM) calculations.
The issue of securing future replacement parts will also be a concern for engineering designers
since STATCOM technology is developing quickly and there is the risk that constituent parts

may become obsolete or the concern manufacture by a particular Owner of certain parts could
cease their production. A strategic spares policy may be applied in this regard.
This group may also manage the Owner interface and fulfill the key witnessing requirements.
Factory Acceptance Tests (FATs) as well as commissioning tests witnessing may be performed
by this group to ensure the equipment is built and can be operated as specified in the contract.
3.3.4 Network Operations
Network Operations involvement will be required in the following areas:
• Operational Planning – securing outages for maintenance and construction
• Control/SCADA requirements
• Cyber Security requirements
To integrate the STATCOM successfully into system operation requires input at the design and
specification stage so that equipment with a sufficient range of operational capability or flexibility
is purchased.
Acceptance of the STATCOM specification/requirements from system operators is therefore
crucial in the procurement process.
3.3.5 Project Management
The Project Management task is necessary as an integrative function tying together all of the
other inputs such as:
• Schedule
• Contract compliance
• Planning consents
• Stakeholder consultation
• Environmental constraints/consents
• Progress reporting
This group will lead the implementation of the STATCOM by managing the planning consents
process and leading the stakeholder consultation required.
Feasibility studies to investigate any environmental constraints that may be necessary as part of
the footprint planning will be managed by this group.
This group will also manage the contract and schedule after the successful bidder has been
selected.
3.3.6 Finance and Legal
The project manager will require legal and specialist financial advice to efficiently manage the
procurement process and to choose the best procurement strategy that ensures value for
money for the Utility or Owner.

The finance and legal group will also provide the commercial requirements.
This group will also obtain financial approval if required.
3.3.7 Asset Management
The asset management team is the group that has final acceptance of the equipment. It is
critical to engage this group early in order to ensure that it meets the required standards and
service specifications and meets all maintenance requirements.
The asset management group may also define preferred Vendors for certain components (i.e.
batteries, test switches) in order to standardize certain equipment across the owner’s complete
system (Fleet management).
They also need to be satisfied that the equipment will meet the long term performance goals.
3.4 Data/Requirements after Planning Specification
After the planning specification has been completed, further data and requirements need to be
compiled to define requirements such as site and environmental conditions, equipment
specifications, maintenance and spares requirements, interfaces and limits of supply etc. This
section outlines the type of data that should be included in the specification and in some cases,
how the data are obtained.
3.4.1 Site and environmental conditions
The following data should be provided:
Site data:
• Description of the geographical location of the site
• Space available and footprint restrictions
• General arrangement drawing of the ac substation where the STATCOM will be
installed
• Single line diagram of the ac substation where the STATCOM will be installed
• Description of interfaces to the ac substation, these should include primary plant
interfaces, protection, telecommunication and control interfaces, SCADA interfaces,
auxiliary supply interfaces
• Geotechnical data of the site
Environmental data:
• Minimum, maximum and average ambient temperatures
• Range of humidity
• Altitude

• Rainfall, snow and ice conditions
• Solar radiation levels
• Keraunic levels or Flash Density maps
• Types and levels of pollution
• Wind speeds
• Seismic conditions
• Distance to sea coast (if applicable)
Emission limits (as required):
• Harmonics
• Electromagnetic field limitations
• Audible noise
• Telephone interference restrictions
• Radio interference restrictions
• Television interference
• PLC interference
3.4.2 General design requirements
General design requirements should include items such as:
• Use of equipment whose reliability has already been proven in other similar projects
• Use of component and equipment redundancy
• Use of fail safe and self-checking design features
• Provision of adequate facilities for testing, alarms, fault indication and monitoring
• Use of equipment which does not require special operating and maintenance
environments
• Use of modular construction to permit rapid replacement of modules containing failed
components or sub-assemblies or a design that has a short mean time to repair
• Standardization of components for different locations utilizing the same type of
STATCOM where practical
3.4.3 Primary plant equipment requirements
The primary plant equipment requirements should list all the applicable standards that are to be
complied with and also define general and specific requirements for the following items of plant.
This list may include internal standards.
• AC circuit breakers
• AC disconnectors
• AC instrument transformers
• Surge arresters
• Power transformers
• Reactors
• Semi-conductor valves (IGBT, IGCT, etc.)
• Valve cooling system

• Capacitors
• Filters
• Insulation requirements
• Steelwork, busbars, clamps and connectors
• Station earthing and lightning protection
3.4.4 Control, protection and monitoring system requirements
The control, protection and monitoring system requirements should list all the applicable
standards that are to be complied with and also define general and specific requirements for the
following systems. List of possible requirements for the control, protection and monitoring
systems are:
Control systems:
• Redundancy
• Human machine interface requirements
• I/O that may be required for external inputs
Protection systems:
• Types of protection functions required and adopted redundancy philosophy (if
applicable)
Monitoring system requirements:
Define requirements for systems such as:
• Sequence of events recorder
• Transient fault recorders
• Dynamic performance recorders
• Power quality recorder
• Remote access/control requirements
3.4.5 Auxiliary systems requirements
Define requirements for the following systems:
• AC auxiliary supplies
• DC systems
• Heating, ventilation and air conditioning systems
• Site security system
• Fire protection
• Any special requirements (UMD/UPS)
•

3.4.6 Other requirements
Miscellaneous items:
• Junction boxes, terminal boxes and marshalling kiosks
• Nameplates and labels
• Outdoor lighting
3.4.7 Civil and building works requirements
The civil requirements are driven by:
 Geotechnical data
 Space requirements
 Seismic requirements
It is highly recommended that the owner performs their own geotechnical analysis prior to
releasing the specification in order to ensure there are no surprises during project
implementation. This can be shared with the Vendors to allow for a more complete bid.
3.4.8 Spares, special tools and maintenance requirements
The spares required for the STATCOM may be specified in such a way that a sufficient number
of spares are provided for a certain number of years based on the failure rates of equipment
and components. This typically applies to semi-conductor valves, capacitor cans and electronic
cards. Spares consumption should then be monitored in the first years of operation to ensure
sufficient spares have been provided. Spares should be stored in such a way that they are
easily accessible and kept on an environment recommended by the components manufacturer.
Requirements for the storage of outdoor equipment should also be specified.
3.4.9 Safety, health and environmental requirements
These will be dependent on the specific utility and their requirements should be applied. Any
required safety systems (i.e. interlocking) should be specified.
Specific requirements to allow for safe maintenance must also be defined and may not
specifically fall into this section. An example is the valve hall temperature; the Vendor may
typically allow the valve hall to run at a high temperature, beyond what the owner deems as
safe working conditions. Therefore, the HVAC system should be specified to bring the Valve hall
temperature down to a safe working level in a prescribed time.
Safety maintenance systems for grounding also need to be considered and the typical Owner
grounding standards may not be sufficient due to the unique nature of the STATCOM (i.e.
grounding of capacitors in the valve hall)
Another environmental hazard to be taken into account in the case of the STATCOM is liquid
materials. There are two kinds of liquids in the STATCOM.

The first one is the oil of the step-down transformer. Nowadays, non-toxic oils, such as mineral
oil, are used instead of polychlorinated biphenyls (PCB) which were used until they were found
to be harmful in the 1970’s. However, although non-toxic oils are used, the transformer of the
STATCOM may contain thousands of liters of oil and precautions must be taken in order to
manage the risk of oil leakage, taking into account the local regulations.
The second liquid in the STATCOM is the cooling liquid, which is used to transfer the heat from
semiconductor switches, LCL-filter reactors etc. to the heat exchanger. In STATCOM
applications with no risk of freezing, plain water is used as a coolant. De-ionized water is
typically used in order to make the cooling water electrically non-conductive. On the other hand,
if the coolant has to be cold resistant, generally ethylene glycol is added to it. Ethylene glycol is
widely used in cooling systems, e.g. in cars. However, it is a toxic compound and may cause
death if consumed, therefore it has to be ensured that it is treated properly and there are no
leakages in the cooling system.
3.4.10 Training requirements
Any training requirements should be specified. Please refer to section 6.10 for more details.
3.4.11 Site Security
Site security is required during all stages of implementation. During construction, prior to
energization, there is a lot of equipment being stored waiting to be installed and needs to be
stored securely. After energization, as with any sub-station, due diligence needs to be taken to
ensure safety of the plant and public.
3.4.12 Interference Requirements
The following sections are provide as a reference to look at some of the main items mentioned
above and is provided to help provide some guidance in specifying these items.
3.4.12.1 Harmonics
Harmonics are sinusoidal voltages or current components with frequencies which are integer
multiples of the fundamental frequency (50 Hz or 60 Hz) at which the electric power systems
operate. Distortion of the fundamental frequency voltage or current waveform, called harmonic
distortion, occurs from the normal operation of equipment and loads with non-linear
characteristics connected to the system. In order to mitigate the undesirable effects of
harmonics such as overheating of generators and capacitors, limiting the power transfer of
transmission lines and telecommunication system interference, design measures are taken to
limit the amount of harmonics generated by equipment with non-linear characteristics.
Equipment utilizing switching converter technology such as a STATCOM generates harmonics.
The level and the order of harmonics generated by such equipment are dependent upon the
design and the configuration [1].
Problems related to harmonics fall into two basic categories:

• Harmonic currents are injected into the supply network by converters and other
harmonic sources. Both harmonic currents and resulting voltages can be considered
as conducted phenomena. The harmonic voltages in supply systems should be
limited to levels that will not result in adverse effects on sensitive equipment. Since
the harmonic voltages result from harmonic currents and impedances, this involves
limiting the harmonic currents injected into the system.
• Harmonic currents in the range between 50 Hz to 5 kHz may induce interference into
communication systems. This phenomenon is more pronounced at higher order
harmonic frequencies because of increased coupling between the circuits and
because of the higher sensitivity of the communication circuits in the audible range.
In order to coordinate the necessary measures for controlling the level of harmonics generated
by a STATCOM in line with the harmonic distortion limits of the utility system, it is essential to
have knowledge of the utility system impedance ZS(h) as a function of frequency at the PCC.
Figure 3.4 Network equivalent model for harmonic studies.
Harmonic performance of the STATCOM installation should be evaluated to determine
compliance with design specifications. Prior to the STATCOM being installed the background
harmonics should be measured. These levels should be compared with the harmonics
measured with the STATCOM operating at various levels of output.
Harmonic measurements need to be taken over a specific period, generally of at least one
week, to yield meaningful results.
When determing the impact of harmonics, not only does one need to determine the impact of
the generated harmonics on the ac system, but also the impact of the existing harmonics,
usually called background harmonics, plus the STATCOM generated harmonics on the rating of
the STATCOM components.
In order to define performance and rating requirements, please refer to IEC 61000-3-6 “Part 3:
Limits – Section 6: Assessment of emission limits for distorting loads in MV and HV power
systems – Basic EMC publication and/or IEEE 519 “IEEE Recommended Practice and
Requirements for Harmonic Control in Electric Power Systems”
3.4.12.1.1 Harmonic performance studies

The purpose of utility harmonic studies related to STATCOMs are to:
• Ensure acceptable levels of system voltage and current distortions, and telephone
interference factors, taking into account existing harmonic levels at the point of
connection
• Ensure acceptable voltage and current harmonic emissions from the STATCOM and
immunity to system harmonic levels by the STATCOM
• Evaluate the harmonic interactions of the STATCOM with the power system under
balanced and unbalanced operating conditions
• Evaluate filter design
In terms of harmonic performance, the STATCOM behaves as a high-order harmonic voltage
source, in contrast to an SVC which, with a TCR branch, can be considered as a low-order
harmonic current source. To analyze the harmonic performance of the STATCOM, the
configuration shown in Figure 3.4 is generally employed.
The “synthesized” ac voltage generated by the converters of the STATCOM is modeled as a
harmonic voltage source, and the magnitude of this harmonic voltage should take into account
the appropriate ranges of system imbalance, voltage and frequency. Depending on the
converter switching frequency and algorithm, interharmonic voltages can be generated. For
harmonic analysis, these voltages should be suitably grouped according to international
standards [8]."
The system harmonic impedance should cover the range of potential equivalent impedances at
the point of connection, which would generally be most influenced by local changes in operating
condition, but must include all power system contingencies and component tolerances which
may affect system harmonic impedance. Particular attention should be given to possible
resonance conditions that may arise due to parallel capacitor installation.
In order to derive the range of potential network equivalent impedance, appropriate frequency
dependent models of the network components are required. The following representations are
typically employed [1]-[6]:
Table 3.1 Network component representation for harmonic studies
Network Component Model Representation
Transmission line and
cables
Detailed geometric line data which allows for the correct frequency
representation being accurate up to 2 kHz.
Transformers Series impedance
Generation plant Appropriate shunt reactance (e.g. subtransient) or fault infeed
Loads Accurate load representation near the point of connection (i.e. inductive,
capacitive and resistive components)
Other shunt
compensation
Appropriate shunt reactance
Filter Discrete components details

For the particular steady-state harmonic under investigation, the appropriate sequence
impedance is used:
Table 3.2 Sequence network impedance
Harmonic under study Network impedance
1, 4, 7, 10, ….. Positive sequence
2, 5, 8, 11,…… Negative sequence
3, 6, 9, 12, ….. Zero sequence
Please note the table above is not applicable to transient conditions. Harmonic performance
studies are performed in the frequency domain and are generally carried out by means of digital
computer programs on a linear, stationary and balanced representation of the system.
Time domain simulations can be used in cases where interaction between the STATCOM and
other power system components may occur leading to possible harmonic magnification, high
inrush currents, control interaction and non-characteristic harmonics. Thus, appropriate
modeling of the STATCOM controls is of importance.
3.4.12.1.2 Harmonic References
[1] “Static Synchronous Compensator (STATCOM)”. Cigré. Prepared by Working Group 14.19.
Edited by I. Arslan Erinmez & A. M. Foss. August 1999.
[2] “Power System Harmonics”. Jos Arrillaga and Neville R. Watson. John Wiley & Sons Ltd.
Second Edition. 2003.
[3] CCITT (1963) Directives Concerning the Protection of Telecommunication Lines against
Harmful Effects from Electricity Lines, International Telecommunications Union, Geneva.
[4] Engineering Reports of the Joint Subcommittee on Development and Research of the
Edisson Electric Institute and the Bell Telephone System, New York, 5 volumes, July 1926 to
January 1943.
[5] IEEE Std. 519: 2014-IEEE Recommended Practices and Requirements for Harmonic Control
in Electrical Power Systems.
[6] IEEE Power Engineering Society. “Tutorial on Harmonics Modeling and Simulation”. TP-125-
0. 1998.
[7] “Power Quality Indices and Objectives”, Joint Working Group Cigré C4.07/Cired (formerly
Cigré WG 36.07). Final WG Report. January 2004. Rev. March 2004.
[8] IEC 61000-4-30 Electromagnetic compatibility (EMC) - Part 4-30: Testing and measurement
techniques - Power quality measurement methods
[9] IEC/TR 61000-3-6 Electromagnetic compatibility (EMC) - Part 3-6: Limits - Assessment of
emission limits for the connection of unbalanced installations to MV, HV and EHV power
systems

3.4.12.2 Flicker
Many loads connected to electric power systems can cause power quality problems at all
voltage levels and for very different power ratings due to their unbalanced and non-linear
behavior characteristics. However, the main sources of power quality problems affecting large
numbers of Owners are the high power industrial loads. The large and rapid variations in active
and reactive power required by such loads, cause voltage variations with appreciable voltage
distortion. The residential and other commercial Owners who are supplied by the same ac
network are then subjected to the impact of these voltage variations [1].
The main industrial loads that can cause disturbance to other Owners are:
• Resistance welding machines
• Rolling mills
• Mine winders
• Large motors with varying loads
• Large variable speed drives
• Arc furnaces
• Rock/mineral crushing equipment
• Wood chipping mills
• Arc welding plants
• Power factor correction capacitor switching
3.4.12.2.1 The need to compensate flicker
Repetitive voltage fluctuations in power systems need to be controlled to reasonable low levels
to reduce their impact on domestic and commercial Owners to an acceptable level.
The main reason for such a control action is the effect of the voltage fluctuations on the light
output of incandescent electric lighting i.e. flicker, that can cause uneasiness, eye irritation,
migraine and headaches.
The voltage fluctuations lead not only to light flicker but also to the malfunction of other sensitive
loads. Some loads are adversely affected by fast variations/fluctuations in the voltage
amplitude. Here are some examples:
• Control action for control systems acting on the voltage angle.
• Braking or accelerating moments for motors (In general will affect the torque
capability of a motor).
• Impairment of electronic equipment where the fluctuation of the supply voltage
passes through electronics parts, for example, computers, printers, copiers and
components for telecommunication.
Usually, in the most sensitive frequency range of the human eye (i.e. 8.8 Hz), repetitive voltage
variations of a few percent (0.3 %) are sufficient to produce annoyance. On the other hand, the
variations that have very low level compared to other disturbances like voltage dips, do not
usually cause any impact on the operation of domestic electric equipment.

The most effective way to control voltage fluctuations and therefore flicker, is to compensate the
reactive power variations of the fluctuating loads, at least at the medium/high voltage levels.
Improved damping performance can also be obtained by compensating the negative sequence
component of active power and harmonics.
It should also be stressed that the voltage stabilization provided by reactive compensation, can
improve the productivity of certain types of loads such as arc furnaces.
3.4.12.2.2 Limits of acceptable flicker and repetitive voltage fluctuations in power
systems
The method of flicker measurement included in IEC standards are mainly based on International
Union for Electricity Applications (UIE) work [2]. These standards provide two indicators for
flicker assessment:
1. Pst “short term flicker severity”, evaluated by an average over a ten-minute
observation period.
2. Plt “long term flicker severity”, evaluated over an observation period of two hours from
twelve Pst values.
Plt is evaluated by means of the following formula:
312
3
1 12
st
lt
i
P
P

 
The two basic flicker indicators are normally used with a probabilistic approach, by means of the
so-called Cumulative Probability Function (CPF), over the total observation period (e.g. a
measurement period of one week in accordance with EN50160 [3] and IEC 61000-3-7 [4]. For
example, Pst99% means the value of the Pst with a 99 % probability not to be exceeded over the
total measurement period. The value of these indicators is shown in Table 3.3.
These indicators have been derived on the basis of study results for 230 V, 50 Hz incandescent
lamps and in particular those rated at 60 W. Countries outside Europe adopt different types of
lamps, e.g. 120 V in North America and 100 V in Eastern Asia. In particular these lamps are
less prone to cause flicker due to their thicker filament construction resulting in higher thermal
inertia. Recently the IEEE has developed a new standard IEEE Std 1453-2004 [5] which adopts
the IEC 61400-4-15 Edition 1.1 2003 [6] which includes the 120 V, 60 W lamps.
3.4.12.2.3 IEC Standards and Recommendations
Electromagnetic Environment and Compatibility levels:
It is the responsibility of utilities and/or power system operators to ensure the electromagnetic
compatibility (EMC) of the whole system and the equipment connected to it. In this respect the
compatibility levels have to be considered as reference values for the coordination of emission
and immunity of equipment connected to the power network. The compatibility levels have to be
considered on a statistical basis, generally adopting the principle that the adopted levels will not
be exceeded both in time and space with a 95 % or 99 % probability.
IEC standards 61000-2-1 [8] and 61000-2-2 [9] are the general standards which respectively
define the different types of disturbance appearing on power systems and the relevant
compatibility levels for low voltage (LV) public networks. However, the existing IEC 61000-2-2

does not give any indication for flicker. It only deals with voltage fluctuations in terms of
maximum acceptable rectangular (square wave) voltage changes at different repetition rates.
Flicker compatibility levels for LV public networks, in terms of Pst and Plt, are given in the second
edition of the IEC standard IEC 61000-2-2. The values included in this standard are shown in
Table 3.3.
Table 3.3 Compatibility levels for LV public networks
Compatibility levels for LV public networks
Pst 1.0
Plt 0.8
General compatibility levels for medium voltage (MV) public networks are given in the IEC
standard IEC 61000-2-12 [10].
Emission Limits:
The emission limit is the admitted disturbance level caused by a particular Owner alone, i.e., the
flicker level for an arc furnace plant.
Low voltage systems:
IEC standard 61000-3-3 [11] and 61000-3-11 [12] cover respectively the acceptable emission
limits for appliances having a phase current less than 16 A and less than 75 A, in the later case
subjected to conditional connection.
The limits specified by IEC 61000-3-3 for flicker severity are Pst< 1 and Plt< 0.65. The
appliances must comply with these limits, as evaluated by standardized IEC flickermeter,
against reference low voltage impedance (for single phase 0.4 + j0.25 Ω, for three phase 0.24 +
j0.15 Ω for the phase conductor).
Medium/High voltage systems:
IEC 61000-3-7 [4] provides the appropriate guidelines and recommendations for connection of
disturbing loads to electric power systems.
In this document the concept of “planning levels” is introduced. Such limits should be
considered by the electric power utilities/system operators as part of their internal quality
objectives, and are supposed to be equal to or lower than the recommended compatibility
levels, in order to assess the impact on the supply system of all consumer loads. Indicative
planning levels proposed are shown in Table 3.4.
Table 3.4 Compatibility levels for LV public networks

Indicative values of planning levels from IEC 61000-3-7
MV HV-EHV
Pst 0.9 0.8
Plt 0.7 0.6
The above values were proposed with the assumption that the transfer coefficient from HV to
LV systems is unity.
IEC 61000-3-7 states that the measurements on the power system enabling flicker
assessments to be made, should be carried out with a minimum duration of one week,
comparing the obtained results, in terms of percentiles Pst99% and Plt99% with the planning
levels.
Considering the 95 % values instead of 99 %, on the basis of the results of several
measurements periods, the following relationship is suggested:
Pst99% = 1.25 Pst95%
Plt95% = 0.84 Pst95%
In practice, the problem that generally arises is the separation of the background disturbance
from the one caused by the specific fluctuating load. The IEC document proposes a procedure
for achieving this when the background noise is low (Pst ≤ 0.5), subtracting the measurement
results without the specific fluctuating load (including any compensating equipment) to the ones
obtained with the specific fluctuating load connected. A cubic summation law is proposed. In
case of higher background levels a more refined approach should be utilized [13].
Some years ago, the Institution of Electrical and Electronic Engineers (IEEE) developed a new
standard for flicker measurement. IEC 61000-4-15 was adopted and approved for being used
as IEEE Std. 1453. IEC 61000-4-15 was incorporated directly into this document as normative
Annex D.
IEEE Std. 1453 defines the following flicker levels for public networks. A summary is presented
in Table 3.5 and Table 3.6.
Table 3.5 Planning levels for Pst and Plt in MV, HV and EHV power systems
Planning levels
MV HV-EHV
Pst 0.9 0.8
Plt 0.7 0.6
Table 3.6 Compatibility levels for Pst and Plt in LV and MV power systems
Compatibility levels

Pst 1.0
Plt 0.8
Table 3.7 summarizes the objectives relevant to flicker among different standards and reference
documents. This Table was extracted from a more complete one included in [14]. The
mentioned document [14] is an excellent reference for Power Quality Indices and Objectives.
Table 3.7 Flicker Objectives and indices
Flicker indices International Standards
or guidelines
Standard/document IEC 61000-3-7
Status International Standard
Where it applies International
Purpose Indicative planning levels
for emission limits
Indices/
assessment
Short term
(10 min)
Pst
99 % weekly
Long term
(2 hour)
Plt
99 % weekly
Period for statistical
assessment
One week minimum
Measurement method 61000-4-15
Flicker Objectives Defines planning levels for
controlling emissions
Objectives
at MV
Pst 0.9
Plt 0.7
Objectives
at HV-EHV
Pst 0.8*
Plt 0.6*
Remarks Covers MV to EHV
*(assuming an attenuation
factor of 1 between HV-
EHV to MV-LV)
3.6.13.3 Flicker References

[1] “Static Synchronous Compensator (STATCOM) for Arc Furnace and Flicker Compensation”.
Cigré. Prepared by Working Group B4.19. Cigré Study Committee B4. Edited by I. Arslan
Erinmez. September 2003.
[2] “Guide to Quality of Electrical Supply for Industrial Installations – Part 5: Flicker and Voltage
Fluctuations”, UIE Power Quality WG 2, 1999.
[3] CENELEC EN 50160: Voltage Characteristics of Electricity Supplied by public distributions
systems. European standard.
[4] “IEC 61000-3-7: 1996- Assessment of Emission Limits for Distorting Loads in MV and HV
Power Systems. Basic EMC publication.
[5] “IEEE Std. 1453: 2004-IEEE Recommended Practice for Measurement and Limits of Voltage
Fluctuations and Associated Light Flicker on AC Power Systems.
[6] “IEC 61000-4-15: 1997 and Ed. 1.1 2003-02. Testing and measurement techniques- Section
15: Flickermeter- Functional and design specifications.
[7] A. Robert and M. Couvreur “Arc Furnace Flicker Assessment and Prediction”. Paper 2.02,
Cired 1993 Conference.
[8] IEC 61000-2-1: Electromagnetic Compatibility, Part 2: Environment, Section 1: Description of
the Environment- Electromagnetic Environment for Low-Frequency Conducted Disturbances
and Signalling in Public Power Supply Systems, May 1990.
[9] IEC 61000-2-2: Electromagnetic Compatibility, Part 2: Environment, Section 2: Compatibility
Levels for Low-Frequency Conducted Disturbances and Signaling in Public Low-Voltage Power
Supply Systems. September 2000.
[10] IEC 61000-2-12: Electromagnetic Compatibility, Part 2-12: Environment, Section 2:
Compatibility Levels for Low-Frequency Conducted Disturbances and Signaling in Public
Medium-Voltage Power Supply Systems. August 2000.
[11] IEC 61000-3-3: Electromagnetic Compatibility, Part 3-11: Limits: Limitation of Voltage
Changes, Voltage Fluctuations and Voltage Flicker in Public Low-Voltage Supply Systems-
Equipment with Rated Current ≤ 16 A. August 2000.
[12] IEC 61000-3-11: Electromagnetic Compatibility, Part 3-11: Limits: Limitation of Voltage
Changes, Voltage Fluctuations and Voltage Flicker in Public Low-Voltage Supply Systems-
Equipment with Rated Current ≤ 75 A. August 2000.
[13] “Medición de la Emisión de Flicker por cargas perturbadoras mediante un simulador de red
normalizada”. Daniel Esteban, Pedro Issouribehere. ANDESCON 1999.
3.4.12.3 Unbalance
Unbalance is a condition in a 3-phase system in which the rms values of the line voltages
(fundamental component), and/or phase angles between consecutive line voltages, are not
equal. For a three-phase system, the degree of the inequality should be expressed as the ratios
of the negative-sequence component (NPS) to the positive-sequence component (PPS).
n
V
v
V





Only the fundamental components shall be used: all harmonic components should be
eliminated e.g. by using a digital fourier transform algorithm. The whole measurement and
evaluation procedure is defined in detail in Standard IEC 61000-4-30 [1].

It is recommended that the Owner specify different values of unbalance for performance and
rating requirements which is utility specific and depends also on the voltage level at STATCOM
connecting point.
3.4.12.4 Unbalance References
[1] IEC 61000-4-30: Power Quality measurements methods. 2003.
[2] CENELEC EN 50160: 1999- Voltage Characteristics of Electricity Supplied by public
distributions systems. European standard.
[3] Cigré 1992 Paper 36-203. A Robert, J. Marquet on behalf of WG 36.05, 1992: Assessing
voltage quality in relation to harmonics, flicker and unbalance.
3.4.12.5 Electromagnetic Fields (EMF)
When voltage is applied to an object such as an electrical conductor, the conductor becomes
charged and surrounded by an electric field. If charges flow along the conductor and thus form a
current, a magnetic field is also created. All alternating electric and magnetic fields induce
currents in electrically conductive objects, including living organisms [1].
Electric fields are usually measured in volts per meter (V/m) or a multiple, for example, kilovolts
per meter (kV/m).
Ground-level electric fields near an overhead line are mainly determined by the voltage of the
line and how far away one is from the line. The conductor-to-ground clearance and the
conductor arrangement are also important factors which have an effect on the electric field.
Likewise, the conductor size and type (single or bundled) may influence the ground-level
electric fields. Finally, in the case of double circuit or multiple-circuit lines, the relative
arrangement of the three phases of each circuit is important, especially with regard to the
maximum field values found. Since the ground is a good electrical conductor, the electric field at
the ground is perpendicular to it and thus usually vertical.
When an electric current flows along a straight wire, the magnetic field lines are circles centered
on the wire. The field strength is proportional to the magnitude of the current and inversely
proportional to the distance from the wire. If the current in amperes is divided by 2π times the
distance away in meters, the field strength is given in amperes per meter (A/m). However
magnetic fields are often expressed in terms of a quantity called the magnetic flux density for
which the modern unit is the tesla (T), since this is a large unit, submultiples of it such as the
microtesla (μT) are more convenient. An older unit is the gauss (G). The relation between these
units (in non-magnetic materials) is:
0 01 10 in theair 1 0.796 /T mG B T H A m    
3.4.12.6 Magnetic Field Measurements
In the case of overhead transmission lines, the magnetic field should be measured in
transversal profiles, 1 meter above the ground.

In the case of substations, like the one associated with the STATCOM, the magnetic field
should be measured in the perimeter of the substation, 1 meter above the ground. The
maximum value, independently of the direction, should be recorded.
The magnetic field should be measured also inside the office building.
The presence of non-permanent vehicles or metal objects must be avoided.
Prior to the measurement, the presence of non-industrial frequency magnetic fields should be
verified.
The magnetic field measuring equipment accuracy must be 5 % or less.
In Figure 3.9 a typical STATCOM substation is presented. The substation perimeter is marked
in red and is the place where the electric and magnetic fields should be measured.
Figure 3.9 Overall layout diagram of Essex +133/-41 MVA, 115 kV STATCOM system. (1 = VELCO 115
kV yard, 2 = FACTS yard, 3 = FACTS building, 4 = VELCO building, 5 = Heat exchangers).
The International Standards and documents related to the measurement of electric and
magnetic fields are listed in the following section [2]-[5]. A summary of limits and recommended
values are described in Table 3.8. Please note, these values will have to be determined by the
Owner.
Table 3.8 EMF Limits and recommended values.
Country/Origi
n
Standard/Documen
t
Applies to B limit
[µT]
E limit
[kV/m]
Observations
ICNIRP 2010 General public 200 5 ---

exposure
Occupational exposure 1000 10
IEEE C95.6-2002 General public
exposure
904 5 10 kV/m in power line rig
Europe Council of the
European Union
General public
exposure
100 5 Frequencies covered: 50
Argentina Res. SE 77/1998 General public
exposure
25 3 Edge of right-of-way and
substation perimeter
Occupational exposure --- ---
United
Kingdom
NRBP vol. 15
Nº2/2004
General public
exposure
100 5 ---
Brasil ANEEL RS Nº
398/2010
General public
exposure
83.33 4.17 Frequencies covered: 60
Occupational exposure 416.67 ----
3.6.16.1 Electromagnetic Fields References
[1] TB 074. Electric Power Transmission and the Environment: Fields, Noise and
Interference. Cigré. Working Group 36.01 (Corona and Field Effects).
[2] ICNIRP Guidelines. - “IEEE Standard Procedures for Measurement of Power Frequency
Electric and Magnetic Fields from AC Power Lines”.
[3] ANSI/IEEE 644-1994. - “IEEE Standard Procedures for Measurement of Power
Frequency Electric and Magnetic Fields from AC Power Lines”.
[4] IEC 61786-1998. - “Measurement of low-frequency magnetic and electric fields with
regard to exposure of human beings - Special requirements for instruments and guidance for
measurements”.
[5] IEC 833-1987.- “Measurement of power-frequency electric fields”.
3.4.12.7 Audible noise (AN)
Noise associated with a STATCOM can be an issue and if not dealt with at the beginning of the
project, may be difficult and expensive to resolve once it is in service. In order to ensure one
meets the requirements, which are typically driven by local requirements, it is highly
recommended to include the requirements in the technical specification.
The Owner should define an acceptable noise limit at the defined boundary and working
locations (such as control rooms, workshops, etc).
The areas of concern are the station boundary (typically 1 metre from the station fence) and
areas where on may be working inside the station. Furthermore, one can specify points of
reception where noise can be an issue (i.e. a house close to the STATCOM).
Using this information, the Vendor can layout his station to ensure the requiements are met in
the areas of concern. This could include building noise abetment or installing noiser equipment
away from areas of concern.

The equipment that is typically the most likely to produce high levels of noise are:
 Valves and Valve cooling
 Transformers
 Ac filters
 Diesel generators (if installed)
3.4.12.7.1 Example Audible Noise Requirements
Control buildings (excluding mechanical work area) and workshop 60 dBA
At the substation property boundary 55 dBA
3.6.18.3 Audible Noise References
[1] IEC 60076-10-1 Standard: “Power transformers – Part 10-1: Determination of transformer
and reactor sound levels- Owner guide.
[2] “Transformer Noise: Determination of Sound Power Level using the Sound Intensity
Measurement Method”. Report by CIGRÉ Working Group 12 of Study Committee 12. Electra Nº
144. October 1992.
3.4.12.8 Radio and Television Interference (RI)
Radio interference is any effect on the reception of a radio signal due to an unwanted
disturbance within the radio frequency spectrum. Television interference is a special case of
radio interference for disturbances affecting the frequency ranges used for television
broadcasting. Radio interference is primarily of concern for amplitude-modulated systems (AM
radio and television video signals) since other form of modulation (frequency modulation (FM)
used for VHF radio broadcasting and television audio signals) are generally much less affected
by disturbances [1].
According to [1]-[3] the interference is characterized by different frequency spectra, different
modes of propagation (guided along the conductors or directly radiated) and different statistical
variations (because of varying ambient conditions).
Depending on the design of the STATCOM, consideration of RI must be taken into account.
This could include screening of the valve hall and application of specific RI filters. In general, it
is usually enough to specify that the STATCOM should not interfere with any existing radio,
television or communication mediums. A list of applicable frequencies should be provided.
RI aspects must also be considered in the design of the HV installation -substations and lines -
used to link STATCOMs with the grid.
Other such sources of RI are:
• Corona
• Discharging on insulators

Guidelines for the procurement and testing of STATCOMS

Guidelines for the procurement and testing of STATCOMS

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