siemens.com/energy/power-transmission-solutions
Trendsetting connections
The world of power transmission solutions
Answers for energy.
Power transmission
solutions
It takes new approaches and new technologies to meet the world’s soaring
demand for energy and to transmit power to where it is needed most.
We a
­ nswer this c­ hallenge with trendsetting technical expertise, ground­
breaking solutions, and the extra portion of experience gained from decades
of market leadership in many fields of power transmission technology.
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Compelling solutions
for any task
The Siemens range of power transmission s­ olutions
­comprises trendsetting, proven, and reliable solutions
for AC and DC power transmission. They help bridge
even the ­longest ­distances in a safe and secure manner,
and they make electricity the ­sustainable, available, and
efficient energy carrier of choice.
Grid access
One-stop turnkey AC
and DC grid connection
solutions from initial
studies and financing
support all the way to
commissioning.
HV cables
FACTS: SVC PLUS
The most economical
alternative for underground AC power
transmission.
A new approach in ­reactive
power compensation for
better ­dynamic stability
and improved power quality
in AC power systems.
FACTS: SC
Series compensation
increases the transmission capacity of an AC
system without compromising its stability.
HVDC PLUS
An innovative, space-­
saving HVDC solution
based on multilevel
VSC technology.
AIS substations
Turnkey high-voltage substations
with air-insulated switchgear based
on a wide range of high-voltage
devices for flexible solutions.
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Grid access solutions
Series compensation:
· Fixed series capacitors (FSC)
· Thyristor-protected series capacitors (TPSC)
· Thyristor-controlled series capacitors (TCSC)
High-voltage DC transmission systems (HVDC)
· HVDC Classic
· UHV DC
· HVDC PLUS
Gas-insulated transmission lines (GIL)
High-voltage cable systems
Flexible AC transmission systems (FACTS)
High-voltage substation solutions
Parallel compensation:
· Mechanically switched capacitors (MSC, MSCDN)
· Static VAr compensators (SVC)
· SVC PLUS® (advanced STATCOM)
· Synchronous condensers (SCO)
· Air-insulated switchgear (AIS)
· Gas-insulated switchgear (GIS)
After-sales services (operation and maintenance)
HVDC
Solutions for low-loss
long-­distance DC ­power
­transmission and for grid
­interconnection.
FACTS: Synchronous
­condensers
Synchronous condenser solutions
provide short-circuit power to
­improve the ­electrical stability
of transmission networks.
GIS substations
Turnkey high-voltage substations with gas-insulated switchgear based on a wide range of
switchgear modules to meet
customer demands.
FACTS: SVC
Static VAr compensation
increases voltage stability
and enables the control of
reactive power.
GIL
The perfect, extremely flexible
choice whenever overhead AC
lines are not an option.
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The world is witnessing a rapid and profound transfor­
mation of the entire energy landscape. Above-average
growth in demand for electrical energy prevails, as
electric power has become the backbone of growth,
­prosperity, and progress. There is no doubt that electricity
is the energy carrier that will blaze the trail into a more
­efficient, more diverse, and more sustainable energy
­system. However, there are new challenges to be
­mastered: Energy market conditions have changed
­fundamentally. Environmental aspects are considered
more important than ever before. Growing urban centers
are characterized by immense power consumption.
Today, our trendsetting transmission solutions pave the
way for huge energy highways that reliably transmit
energy from where it is sustainably generated to the centers of ­consumption – over distances of hundreds or even
­thousands of kilo­meters. They enable existing AC grids
to operate at much higher utilization rates, while, at
the same time, meeting higher demands on reliability
and power quality. They help integrate the various
­renewable energy sources that have gained increasing
importance. They support the emergence of highly
­performant ­international grid infrastructures spanning
entire economic areas and even continents.
At Siemens, we have envisaged this transition process
at a very early stage. We have consequently embarked
on the development of innovative technologies that
help master the new challenges. This is why we already
have a tradition of creating thought-leading solutions
that make possible the efficient transmission of power
to wherever it is needed.
The portfolio overview on the following pages
illustrates how our solutions unlock the power of
­technology to meet the challenges the transformation
of the energy ­system entails.
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The world’s first ultra-high-voltage direct current (UHV DC)
transmission system connects the Yunnan and Guangdong
provinces in China. The s­ ystem operates on a voltage level
of 800 kV and is a new milestone in bulk power transmission. Characterized by its ­particularly low transmission
losses, it transmits 5 GW of power generated by hydropower plants over a distance of 1,418 kilometers from
Chuxiong substation in Yunnan to the energy-hungry
Pearl River delta in Guangdong p
­ rovince – one of the
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most densely urbanized regions in the world and one
of the main hubs of China’s economic growth.
Commercial operation of the first 800-kV pole started
in December 2009, and the complete bipole has been
in operation since June 2010. The system uses two
series-connected 12-valve pulse groups per pole; one
is rated 400 kV, the other is rated 800 kV and feeds the
DC line.
UHV DC
A new dimension of efficiency
in DC power transmission
The benefits of Siemens
UHV DC solutions
Ability to efficiently transmit bulk
power over very long distances: up
to 8 GW at a voltage of ±800 kV
30–50 percent reduction in trans­
mission losses and CO2 emissions
with UHV DC compared to UHV AC
Significantly smaller footprint and
lower overhead line costs in comparison with UHV AC ­transmission
UHV DC thyristor module equipped with 6-inch thyristors
Demand for electric power keeps rising, but many
existing AC transmission systems have already reached
their capacity limits. At the same time, the share of
­renewable energy in the energy mix is growing. How-­
ever, wind, solar, and ­hydropower is mostly generated
far away from load ­centers. That’s why there will be a
need for bulk power transmission corridors that can­
­efficiently handle long-­distance power transmission in
the gigawatt range. That’s why ­innovative transmission
technologies are required for point-to-point longdistance bulk power transmission.
Siemens UHV DC technology takes high-voltage direct
current (HVDC) power transmission to the next level. It
makes long-distance power trans­mission at a voltage level
of ±800 kV technically as well as economically feasible
for the first time ever. A single UHV DC system provides
power capacities of up to 8 GW. Siemens UHV DC offers a
key to increased p
­ erformance and robustness of the trans-
mission grid, to keeping pace with the steadily growing
energy ­demand, and to a highly efficient way of carbon
emissions reduction.
The UHV DC converter consists of a number of thyristor
modules equipped with new Siemens 6-inch thyristors,
which are connected in 12-pulse groups. A major ­benefit
of this layout is the relatively small size of the ­converter
transformers. Furthermore, it increases the ­redundancy
of the system, as each of the four converters of plus and
minus pole can be bypassed and the assigned DC line can
operate at a reduced voltage level of 400 kV.
Thanks to thorough R&D efforts, Siemens is able to
­produce the entire range of components required for
800-kV DC power transmission and supply complete
UHV DC systems from a single source.
4"
5"
6"
High-performance Siemens thyristors
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Photo © Hawkeye Photography
The first order for Siemens’ innovative HVDC PLUS
­tech­nology was the Trans Bay Cable project, a submarine
HVDC transmission link between San Francisco’s city
­center and a Pacific Gas & Electric substation near
­Pittsburg, California. The system transmits 400-MW
active power and ±170-MVAr reactive power as a
STATCOM to increase the stability of the surrounding
AC system.
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INELFE, the world’s first VSC HVDC with two parallel
­systems transmitting 1,000 MW each, is under con­
struction between Baixas, west of Perpignan in France,
and Santa Llogaia, south-west of Figueras in Spain. It is
an important component of the trans-European electricity
network. The converter stations use HVDC PLUS voltagesourced converters in a modular multilevel converter
arrangement with a transmission voltage of 320-kV DC.
HVDC PLUS
Innovative multilevel technology
for DC power transmission
The benefits of Siemens
HVDC PLUS systems
Little space requirements thanks to
compact, modular multilevel design
Supply of passive networks and
black-start capability
Grid access for onshore and offshore
power generation from renewable
energy sources
Converter tower
Siemens HVDC PLUS, which is based on multilevel voltagesourced converter technology, ushers in the next generation of high-voltage direct current transmission technology. It is one of the most innovative technological answers
Siemens has developed to master the energy challenge: an
advanced, modular, and universally applicable solution for
the transmission of up to 1,000 MW and above.
HVDC PLUS is the preferred solution wherever space
is at a premium. It is ideally suited for the onshore grid
­connection of power-consuming remote offshore
­platforms as well as power-generating offshore wind
farms. It helps ensure and even improve the availability
of e
­ lectricity in densely populated megacities, and it
improves the performance of the transmission grid
with regard to system security.
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At the core of the system are self-commutated, voltagesourced converters (VSCs) in modular multilevel-converter
(MMC) configuration. This makes possible a nearly ideal
sinusoidal waveform on the AC side and smooth DC voltage without intensive high frequency and harmonic filtering. Moreover, the MMC topology allows for low switching
frequencies, resulting in lower system losses, and its modular design ensures flexible converter station layout.
The VSC offers independent control of active and reactive
power, which makes HVDC PLUS fully suitable for AC voltage control, which is particularly helpful in connections
with weak network conditions. Reactive power can be
­generated or consumed independently from active power
transmission, and the system can also provide unbalance
control to compensate large single-phase loads.
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Two-level
vac
Three-level
Multilevel
vac
vac
t
vac
t
t
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Photo © A’lok Choy, On-Off-Media.net
The Gwynt y Môr 576-MW offshore wind farm lies 13
­kilometers off the North Wales coast. It generates power
with 160 Siemens 3.6-MW wind turbines, producing
around 1,950 GWh of electricity per year – enough to
power one-third of all Welsh homes – and ­saving around
1.7 million tons of CO2 each year.
The array of Siemens’ wind turbine generators are
­connected to the two new offshore substation platforms
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via 33-kV cables in the seabed. Once onboard the
­platforms, the wind-generated power is transformed to
high voltage (132 kV) for efficient transmission back
to a new onshore substation at St Asaph in North Wales.
The onshore ­substation is also built by Siemens and
includes two sets of reactive power compensation
­equipment each c­ ontaining a 50-MVAr SVC PLUS unit.
Grid access solutions
Proven solutions for challenging
environments
The benefits of Siemens
grid access solutions
Proven track record and experience
in offshore grid access projects
Customized solutions based on
proven technology and experience
Turnkey delivery minimizing
technical and financial risks
OSP East of Gwynt y Môr wind farm
Large-scale renewable energy sources, such as offshore
wind farms, are posing new challenges for transmission
systems and electricity networks. The share of renewable
energy in the energy mix is expected to dramatically
increase in the next decades, as countries strive to meet
renewable energy and CO2 reduction targets and to ensure
the security of power supply. This increase in renewable
generation is matched by the demand for proven grid
access solutions that are capable of reliably transferring
power from large-scale renewable energy projects to the
transmission system.
Siemens’ AC and DC-based grid access solutions are
­suitable for the transmission of up to 1,000 MW
and beyond. The approach is to provide turnkey grid
access solutions, ensuring seamless project coordination
and reducing interface risk for the customers. Siemens’
­comprehensive range of ­solutions comprises early
­feasibility and network studies to ensure grid code
­compliance as well as design, manufacturing,
­construction, and ­commissioning of onshore and
offshore substations.
Offshore wind grid access projects are often remote
from the centers of demand or even the established
­transmission infrastructure and located in harsh offshore
environments; large-scale renewable energy projects
require complex electrical solutions. With the scale and
transmission distance of these projects ever-increasing,
Siemens is able to draw on its position as a technology
leader in high-voltage AC and DC power transmission to
provide highly reliable and customized solutions based
on proven Siemens technologies.
Siemens’ experience in these projects is unparalleled,
and Siemens specialists in several countries deliver highvoltage AC and DC grid access solutions across Europe
and beyond. Outstanding experience, a comprehensive
range of products, services, and solutions as well as
proven technology make ­Siemens the supplier of choice
when it comes to highly reliable grid access solutions.
Onshore substation at St Asaph, North Wales
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The 500-MW Greater Gabbard offshore wind farm
in the Thames Estuary off the British coast has been in
operation since 2010 and comprises 140 wind turbines.
The wind farm delivers enough power for more than
500,000 British households. Three 45-kilometer-long
cables bring the power onshore at Sizewell, Suffolk, where
three containerized Siemens SVC PLUS converters connect
the wind farm to the national transmission network.
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Siemens SVC PLUS provides voltage control and increases
grid stability in the most flexible and innovative way:
The highly successful system comes either containerized
or installed inside a building. Today, numerous SVC PLUS
systems all over the world help handle voltage fluctuations, increase system stability, and support the integration of renewable power into the grid.
FACTS – parallel compensation
Improved grid stability
and power quality
The benefits of Siemens
parallel compensation
Prevention of voltage collapses
and blackouts
Higher dynamic stability of
AC transmission systems
Improved power quality
SVC in Devers, USA
Parallel compensation
Mechanically switched capacitors and reactors (MSC,
MSR), which can also be equipped with a detuning
­network (MSCDN) to avoid system resonances, provide
the simplest version of parallel compensation offsetting
the network voltage.
The fast and variable means of voltage control and
­network stabilization is the well-proven static VAr
compen­sator (SVC). This individually designed installation
continuously controls and changes the voltage by switching and controlling reactive power elements. Siemens
uses state-of-the-art light-triggered thyristors as the
key power ­electronic element. Any operating range and
mode can be accomplished by selecting an optimal
­configuration. The SVC control allows multiple ways of
system ­monitoring and system voltage stabilization,
including power o
­ scillation damping. The SVC’s major
task is the support of the network during contingencies
resulting in increased overall system stability.
Hence, significantly less space is required. Small
standard configurations (±25, ±35, and ±50 MVAr)
are available as containerized solutions, which also
allows for easy relocation.
Larger operating ranges are also possible with either
­multiple containers or open-rack configurations installed
in a building. The underlying technology is also actively
used outside the utility sector in traction power supply
or industrial applications, such as flicker compensation.
The SVC PLUS solution, a STATCOM (static synchronous
compensator) provides similar functionalities, but features
these in a space-saving and even more flexible manner.
It is based on voltage-sourced converter (VSC) technology
with ­continuous control using high-performance transistors (IGBTs). The multilevel topology of converter modules
results in a nearly sinusoidal voltage waveform which
reduces the need for filtering harmonics to a minimum.
SVC PLUS converter arrangement
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A large-scale transmission project was started in Brazil in
2010 to provide power for the center of the Amazon area:
a 500-kV double-circuit overhead trans­mission line with
a total length of about 1,500 kilometers is being con­
structed to connect the cities of Tucuruí and Manaus,
including a 340-km, 230-kV connection from the city
of Jurupari to Macapá. The system is expected to be
ready for commercial operation in 2013.
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Siemens engineered and delivered three static VAr
compensators (SVC) and 18 fixed series capacitors (FSC).
The FSCs, installed in parallel and in the range of 200 MVAr
to 800 MVAr each, will reduce the reactance of the
transmission lines to improve transmission capacity,
minimize losses, and reduce voltage drop over the long
distance. This will support and improve the stability of
the electric network in the Amazon area.
FACTS – series compensation
Higher efficiency and investment
deferral for AC grids
The benefits of Siemens
series compensation
Increased power transfer
capability of the grids
Better use of existing AC
transmission lines
Efficient, modular, and ­
cost-effective solution
FSC Lugo, USA
Series compensation
Series compensation devices electrically shorten the
­transmission line by reducing the line impedance.
The transmission angle is also reduced. This results
in an increase in power transfer capability and allows
the more efficient use of existing infra­structures.
The most common application is the FSC, which consists
of the actual capacitor bank. The capacitors are protected
against overcurrents and overvoltages by three different
devices: arresters (metal oxide varistors, MOVs), triggered
spark gaps, and finally a bypass switch. As the whole
installation is on high-voltage potential, everything except
the bypass switch is mounted on a platform.
The thyristor-controlled series capacitor (TCSC)
provides additional features compared to an FSC.
A thyristor-­controlled reactor in parallel to the
capacitor bank allows influencing the impedance
smoothly. Power oscillation damping and load flow
­control, which all increase the system’s stability,
are the major advantages of this application.
The thyristor-protected series capacitor (TPSC)
replaces the MOVs by a thyristor valve allowing
a quicker reinsertion of the bank after faults.
FSC Castanhal, Brazil
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Siemens installed three 60-MVAr synchronous condensers
at the Georgia Black Sea HVDC station in June 2012. This
synchronous condenser solution will support the trans­
mission network between Georgia and Turkey with the
required short-circuit power in order to operate the newly
installed HVDC back-to-back station.
In Denmark, Siemens has delivered a 250-MVAr synchro­
nous condenser solution that will start operation in
summer 2013, providing the transmission system with
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a ­short-circuit power of more than 800 MVA in addition
to reactive power control. The installation of this standalone synchronous condenser solution will enable the
trans­mission system operator Energinet.dk to operate the
trans­mission network without the need for a large thermal
power plant. This makes the installation an economically
and environmentally advantageous investment enabling
the infeed of large amounts of renewable energy into the
transmission network.
FACTS – synchronous condensers
Bringing grids in line with
new requirements
The benefits of Siemens
synchronous condensers
Provision of short-circuit
power and inertia
Steady-stage and dynamic
voltage control
Reactive power control of
dynamic loads
Synchronous generator
Synchronous condenser solutions are being “reintroduced”
worldwide to support today’s transmission system
requirements. The addition of renewables-based power
generation to the energy mix, phase-out of conventional
power plants, new HVDC systems, and the extension of
power supply systems to remote areas influence the
stability of transmission networks. Hence, the installation
of synchronous condenser solutions has become
necessary to provide sufficient short-circuit power,
reactive power, and inertia to the transmission systems.
amounts of short-circuit power and providing inertia
due to its rotating mass.
Siemens offers tailor-made turnkey synchronous
condenser solutions to address the customers’ needs
based on proven, reliable in-house equipment, extensive
know-how on transmission system requirements, and
project execution experience. Siemens supplies a broad
range of generators up to 1,300 MVA on full speed. The
generators are based on air, hydrogen, and water-cooled
techniques depending on customer requirements.
The Siemens synchronous condenser solution comprises
a synchronous generator connected to the high-voltage
transmission network via a step-up transformer. The
synchronous generator is started up and braked with a
frequency-controlled electric motor (pony motor) or a
starting frequency converter. When the generator has
reached operating synchronous speed depending on the
system frequency, it is automatically synchronized with
the transmission network, and the machine is operated as
a motor providing reactive and short-circuit power to
the transmission network.
The generator is equipped with either a brushless exciter
or with a conventional static exciter with brushes. The
two solutions have different characteristics with respect
to dynamic behaviors, and are selected according to the
project requirements. Contrary to power-electronics-based
static VAr compensators (SVCs), a synchronous condenser
features the major advantages of injecting large
Synchronous condenser building of the HVDC Black Sea Transmission
Network, Georgia
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In the past, high-voltage substations used to be industriallooking eyesores that were usually banished from urban
centers. Today, Siemens’ state-of-the-art substation technology, engineering, and design makes it possible to integrate such substations into urban settings in a architecturally and stylistically compatible manner.
West Bay Super 1 substation in Doha, Qatar, for instance,
reflects the scale of the city’s greenfield development
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projects, as well as the local utility’s commitment to have
these substations complement the surrounding cityscape.
Despite the enormous power requirements of the substation, turnkey contractor Siemens was able to control the
building and plot size by installing ultra-compact gas-insulated switchgear (GIS). Siemens finished the building with
design embellishments that reflect the contemporary feel
of West Bay and make a striking architectural statement.
High-voltage substations – turnkey solutions
The key to successful projects
The benefits of Siemens
­turnkey substation solutions
One-stop approach comprising all
technical, financial, and ecological
aspects of the station’s entire life cycle
Customized solutions based on
proven Siemens technologies, even
for the most challenging demands
Freedom from coordination efforts
and minimized financial and technical risk
Siemens turnkey high-voltage substations prove their extraordinary
reliability every day in virtually all regions of the world
Siemens has all it takes to create and operate turnkey
­substation solutions that efficiently support the reliable
supply of electrical power on all voltage levels: from
decades of practical experience as an EPC contractor from
a vast number of projects all over the world to unparalleled
­expertise in all transmission processes and all the way to
proven excellence in project management. A distinguished
tradition of ­innovation in power engineering, customized
financing solutions, and outstanding quality standards in
all production facilities worldwide round out the picture.
Turnkey solutions for high-voltage substations provide
the strong performance of one of the world’s leading
engineering companies and one-stop supplier of power
transmission products, solutions, and services. The scope
of services comprises consulting, project ­man­agement,
system planning, engineering, commissioning, and
­comprehensive after-sales support. Centers of ­com­­­pe­­tence and branches all over the world create local
value and ensure that Siemens experts are within close
reach of every project.
Feasibility studies
Financing support
and consulting
Overall project
management
After-sales
services and
recycling
Engineering
and design
Site facilities
and civil works
Training
On-site installation
and commissioning
Production
Transport
Procurement
Factory testing
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FGC, a Russian power plant operator, intended to improve,
expand, and secure the electrical power supply for the
future. They decided to replace a 40-year-old air-insulated
switchgear (AIS) by a modern and space-saving gas-insulated switchgear (GIS).
The challenge for Siemens was to deliver nine bay
­sections 500 kV, 32 bay sections 220 kV, and six bay
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s­ ections 110 kV within ten months. The AIS had to
be gradually replaced by the modern GIS in the inner
city of Moscow without interrupting the power supply
during installation. In 2007, Siemens constructed the
GIS on minimal space on the area of the former AIS,
­setting an example for reliable and flexible technology
implementation.
High-voltage GIS substations
Reliable, flexible, and
outstandingly compact
The benefits of Siemens
gas-insulated switchgear
High reliability, availability, gas­
tightness, and high degree of safety
Economic efficiency, long service
life, little maintenance requirements, and low life cycle costs
Compact design, good accessibility
and ergonomics, high degree
of adaptability to individual
requirements
Siemens GIS have proven their reliability in numerous indoor and outdoor installations
Siemens supplies high-voltage GIS for rated voltages from
72.5 kV up to 800 kV. The comprehensive product range
holds ideal solutions for all indoor and outdoor switching
applications up to the highest performance rates. More
than 28,000 GIS bays for voltage levels of up to 750 kV
are currently in operation in substations all over the world.
Siemens particularly focuses on sophisticated switchgear
solutions for installation in challenging locations. Highvoltage substations equipped with Siemens GIS can be
integrated in urban settings in a way that makes them
­virtually invisible and entirely compatible with densely
populated districts. These substations are sometimes
­completely underground, such as in Anaheim, California,
or they are incorporated in other structures, such as
­multi-story buildings and car parks and even historical
buildings. Siemens GIS are also an essential part of grid
access solutions for renewables – an aspect that is
­increasingly gaining importance.
One of the main challenges today is to bring high-voltage
levels right into the centers of urban areas. This requires
switchgear that feature a small footprint, the utmost reliability, and very low noise and electromagnetic emissions.
Siemens GIS are ideally suited to meet these requirements.
Thanks to their compact design, Siemens GIS need very
little space. They consist of a small number of modules
that are combined into many field arrangements, meet
all space and capacity requirements, and need very little
maintenance. Moreover, Siemens GIS excel through low
losses, outstanding gastightness, and very low electro-
magnetic field emissions. They are virtually main­tenancefree systems with low life cycle costs and high levels of
reliability and safety, which is an issue of particular concern in urban settings, where large numbers of people are
in close proximity to the substation buildings.
Offering the highest-possible degree of mobility and
­flexibility with mobile high-voltage switchgear mounted
on trailers or within containers, Siemens’ “portable power
solutions” are a proven one-stop option whenever it comes
to providing switchgear in next to no time and for temporary purposes, as is the case in disaster areas, for instance.
With more than 40 years of GIS manufacturing experience, the largest installed base of gas-insulated switchgear, and a long track record of superior turnkey supply,
Siemens is able to provide one-stop GIS solutions that also
comprise all secondary technology, procurement, installation and commissioning on-site, and operational training.
What’s more, Siemens is also able to offer outstanding
service and support in all matters of high-voltage substation technology. A tight-knit global network of regional
business units, technical experts, and experienced engineers makes products and technical expertise available at
short notice around the globe.
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In 2007, Siemens commissioned India’s first 765-kV ­­
sub­station at Seoni in Madhya Pradesh for the Power Grid
Corporation of India Ltd. (PGCIL). Seoni substation is
the point at which the Sipat power plant feeds power
into India’s western and northern supply networks.
The scope of delivery comprised 14 air-insulated switching
bays for a voltage level of 800 kV, six 500-MVA trans­
formers, civil works, and protection and control
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equipment. The commissioning of the plant and the
associated raising of the transmission voltage from
400 to 765 kV were celebrated as India’s “entry into a
new age in power supply.” In the meantime, Siemens
commissioned a number of further 765-kV substation
projects, thus continuing to be a leading player in the
Indian transmission sector and enabling PGCIL to boost
the power transmission infrastructure of India.
High-voltage AIS substations
Engineered for all
environmental conditions
The benefits of Siemens
air-insulated switchgear
Robust, time-tested components
and systems based on over 80 years
of practical experience
Easy implementation of virtually any
application and substation layout
thanks to modular design
Outstanding degree of availability,
reliability, and operational safety
More than 80 years of experience are the basis for today’s Siemens substations equipped with AIS
Siemens substations with air-insulated switchgear (AIS)
are renowned for highest reliability, economical operation, and low maintenance requirements. An integrated
provider of high-voltage systems for more than 80 years,
Siemens produces all relevant switchgear components
for AIS up to 800 kV as well as power transformers and
secondary technology, such as protection, monitoring,
and control systems and devices.
Siemens AIS substations meet even the most demanding
­challenges, because the Siemens experts always consider
the electrical parameters as well as the environmental
conditions to which a substation is exposed.
The modular design of all Siemens AIS switchgear makes
possible the easy implementation of a wide range of standard applications. Moreover, particular ­solutions, such as
step-up systems at power stations, the connection of
power from renewable sources, and large ­transformer
substations in extra-high-voltage transmission systems,
can be set up, as the Siemens ­product range includes
­conductors for rated currents of up to 8,000 A and
­short-circuit currents of up to 80 kA. Moreover, Siemens
also supplies particularly space-saving compact and
­portable air-insulated switchgear solutions.
Siemens’ comprehensive range of services includes
all ­studies required in advance of the construction or
­modern­­ization of a high-voltage substation, the selection
of high-voltage devices, and planning and design for all
required fields of engineering. This ensures the proper
consideration of static loads for steel and civil works
and the protection of switchgear facilities and workforce.
Proper lightning protection as well as the observance
of possible seismic loads are also taken into account.
Moreover, around-the-clock service for entire substations
is available.
AIS for the grid connection of an onshore wind farm on the island of Fehmarn, Germany
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In Germany, the expansion of Frankfurt Airport required
existing 220-kV overhead transmission lines routed in
close proximity to the new runway to be undergrounded
for a d
­ istance of about one kilometer. The line operator
Amprion c­ on­sidered two alternative solutions, conventional
­underground cables versus gas-insulated lines (GIL), and
finally decided to install a GIL, which was directly buried,
similar to a pipeline.
24
One reason for the decision was the cutback of space
­consumption by 40 percent and the reduction of electromagnetic fields (EMF) by more than 90 percent compared
to the power cable solution – an appreciated benefit in the
­EMF-sensitive environment.
The project is the first buried GIL in Germany and its
two circuits provide a continuous transmission capacity
of 1,800 MVA each.
GIL
The next-generation
transmission line
The benefits of Siemens
gas-insulated lines
High economic efficiency thanks
to very low losses, no need for
phase angle compensation, and
maintenance-free design
High degree of safety and
outstanding EMC properties
Perfect complement to overhead
lines thanks to high transmission
capability
GIL ensure minimal EMI at PALEXPO fairground in Geneva, Switzerland
The space that is available for transmission systems is
more restricted than ever before, and environmental
requirements, such as EMC and fire protection, have
gained in importance. Siemens’ second-generation GIL
for high-power transmission are the best option when
environmental or structural considerations rule out the
use of overhead transmission lines. The outstanding
features of a GIL system are its high transmission capacity,
an EMC superior to any other transmission system, low
losses, a high degree of safety, and flexible installation
options. GIL can be laid aboveground, buried directly in
the soil, or installed in tunnels.
GIL consist of two concentric aluminum tubes. The inner
conductor rests on cast resin insulators that center it
within the outer enclosure – a sturdy aluminum tube that
provides a solid mechanical and electrotechnical containment for the system. To meet the latest environmental and
technical aspects, GIL are filled with an insulating gas mixture of mainly nitrogen and only a small percentage of SF6.
During service, the fully encapsulated design protects
­Siemens GIL against environmental influences. The use of
high-quality materials make possible an absolutely maintenance-free product that requires only external inspection.
Siemens has nearly forty years of experience of installing
GIL in the most challenging surroundings. Thirty-five
­projects with an overall tube length of more than
90,000 meters are in operation all over the word, including ­installations within major cities such as Geneva as
well as various vertical and inclined lines to cavern power
plants in Europe, Asia, and Africa. GIL from Siemens
­invisibly transmit power into urban centers and bridge
­distances where overhead lines are unsuitable.
GIL – technical data
Rated voltage
245 to 550 kV
Typical rated current
(higher values on request)
up to 4,500 A
Rated short-circuit current
63 kA/3 s
Insulating gas
N2 and SF6 mixture
Typical system length
100 m to 100 km
Impulse withstand voltage
1,050 to 1,675 kV
Capacitance
55 nF/km
Overload capacity
p to 100%
u
depending on design
and requirements
Typical outer diameter
~375 to 517 mm
Weight per phase approx.
50 kg/m
25
Three 220-kV systems, 26 110-kV connections, as well as
149-MV connections supply power to the steel plants in
Salzgitter and Peine, Germany. Siemens was involved in
determining the cable route, carried out implementation
planning and construction site management, calculated the
current ­carrying capacity and pulling force, and finally laid
and installed the 220-kV and 110-kV cables during plant
operation – a total of 13 km of 220-kV cable, 46 km of
110-kV cable, and more than 100 km of MV cable.
26
Siemens also accomplished the high-voltage connections on
the converter platforms of the Borwin 2 and Helwin 1 wind
farms from planning all the way to commissioning. The
main task was the connection of two 600-MVA transformers
and four shunt reactors to a 170-kV GIS on the low-voltage
side and the connection of the transformers to a 362-kV GIS
on the high-voltage side. More than one kilometer of different cables with conductor cross section of 1,200 mm2 and
2,000 mm2 had to be arranged on minimum space.
High-voltage cable systems
Customized solutions for the
power systems’ lifelines
The benefits of Siemens ­
high-voltage cable systems
Long-standing experience in
complex cable-laying projects and
in collaboration with international
contractors, project management,
and documentation
Technically and economically
optimized, non-proprietary solutions
Short reaction times for fault
clearance
Installation on-site
High-voltage cable systems are the lifelines of power
transmission systems. Today, increasingly limited
availability of space and other external factors restricting
the transmission capacity of cable systems call for
solutions of increasing tech­nical sophistication: the
need to ensure reliable power supply of megacities,
the soaring energy demand in emerging regions, the
increasing share of renewable energy in the energy mix.
Siemens provides the full range of one-stop services
for high-voltage cable systems up to 550 kV as well as
vendor-neutral advice and support for entire systems
and accessories. These services comprise all steps from
engineering all the way to commissioning and final
testing on a turnkey basis. 150 years of technical
experience in cable ­laying from initial calculations all
the way to cable termination and project commissioning,
as well an excellent overview of the entire market, help
select the right technologies and high-grade materials
for any individual requirement in accordance with national
and international regulations and guidelines.
Assistance in system retrofits, conversions, and exten­
sions, as well as in the dismantling and recycling of old
installations rounds out the range of available services.
HV cables – technical data
Rated voltage
60 to 550 kV
Types of cables
XLPE, oil-filled
Typical rated current
(higher values on request)
up to 2,500 A
Rated short-circuit current
208 kA/3 s
Insulation material
XLPE
Typical system length
20 m to 100 km
Impulse withstand voltage
325 to 1,675 kV
Outer diameter
Weight per phase
60 to 150 mm
3 to 40 kg/m
27
The Australian interconnector Basslink is an HVDC trans­
mission system that links the power grids of the states of
­Tasmania and Victoria. Siemens supports the operator of the
interconnector with a customized services package that
includes necessary upgrades and spares supply over the life
cycle of the system, as well as a 24/7 expert support line. In
case of system outages or urgent customer queries, senior
experts are available to react immediately and propose
appropriate recovery measures. Remote access functionality
28
of the control and monitoring system makes possible
­immediate status ­analysis and enables Siemens to efficiently
guide the ­customer’s staff on-site in clearing the fault.
Basslink has a world-record-breaking availability of over
98 per­cent including scheduled outages. This underscores
the quality of the system, the qualification of the operations
team, and the quality of the support services that Siemens
­provides. The proximity and cooperation between user
and supplier is essential for an asset which is supposed to
operate efficiently, safe, and secure for more than 30 years.
After-sales services
The secret of better availability
and reliability
The benefits of Siemens ­
after-sales services
Customized service packages
Maximal facility availability
Fast return on investment
Siemens services ensure expert maintenance throughout the entire life cycle
of transmission equipment
Siemens is an established service provider for offshore
and onshore AC substations as well as for HVDC systems.
Driven by the understanding that creating value for the
customers and managing risks is vital, the company
­provides a full range of valuable and reliable operation
and maintenance services, such as comprehensive
lifetime asset management services, remote diagnostics,
and 24/7 expert hotline. These services, proven in various
projects, such as Basslink, the interconnector between
the Australian mainland and Tasmania, the Moyle
­Interconnector between Ireland and Scotland, and
­Neptune and Trans Bay Cable in the USA, help ensure
first-class performance for a sustainable and secure
power supply with DC long-distance transmission.
Keeping up with high standards of health, safety,
and environmental protection is the number one
priority at Siemens. The company’s effective business
management systems are certified according to
­international standards. They provide a structured
approach for the identification of hazards and risks.
­Adequate operational processes and procedures help
­identify, control, and eliminate such hazards.
Siemens delivers comprehensive lifetime asset services
for equipment and structures and provides proven
systems for asset management and traceability. These
­services ensure the highest possible degree of availability
and ­reliability throughout the entire life cycle of an asset.
Trans Bay Cable HVDC PLUS system, USA
29
Published by and copyright © 2013:
Siemens AG
Energy Sector
Freyeslebenstrasse 1
91058 Erlangen, Germany
Siemens AG
Energy Sector
Power Transmission Division
Transmission Solutions
Freyeslebenstrasse 1
91058 Erlangen, Germany
For more information, please contact
our Customer Support Center.
Phone: +49 180 524 70 00
Fax:
+49 180 524 24 71
(Charges depending on provider)
E-mail:support.energy@siemens.com
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or their respective owners.
Subject to change without prior notice.
The information in this document contains
general descriptions of the technical options
available, which may not apply in all cases.
The required technical options should therefore
be specified in the contract.