Power Transformers

Specializing in reliable solutions with maximum efficiency and availability. Siemens Transformers support grid operators in giving their customers state-of-the-art equipment and energy that is safe and affordable.

Tailored to meet specific customer needs - Daily savings with efficient transformers - Investment pay-offs - Eco-friendly

Find out how our innovations are shaping the future of transformers

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DC compensation for power transformers

Are you annoyed by the increased noise and loss levels in your power transformer caused by DC? We have the perfect solution!


Reliable, long-lifecycle solutions built to customer requirements

For more than a century, power suppliers and industrial companies have relied on Siemens for its reliable and efficient power transformers. Almost all of them, ranging from power ratings from 20 MVA to units well above 1,000 MVA,and 20 kV to 1,100 kV are tailor-made.


Siemens offers a complete chain of services – from consulting to design, from manufacture and transport to commissioning and Transformer Lifecycle Management. As one of the leading transformer manufacturers worldwide, Siemens Transformers offers a tight and responsive competence and service network in more than 190 countries in the world.

Daily savings

Siemens Transformers' services and products ensure daily savings for customers: There are the savings in capital expenditure for regional manufacturing plant setup and for acquiring the broad experience and in-depth knowledge required for creating custom unit designs. The benefits of minimized failure rate and losses, low-noise transformers, units with DC compensation, and monitoring systems for preventive maintenance, on the other hand, translate into savings in operational expenditure.

Minimized risk of failure

Siemens power transformers can be integrated into any kind of power management system. You can opt to integrate them into any cloud-based monitoring system, such as MindSphere. This gives you insight into the current operating condition of the transformer and critical loads, thus facilitating the prevention of power outages.


 In addition, Siemens Transformers offers a comprehensive Pretact® solution, designed to maximize grid availability by minimizing the consequences of both unplanned outages and planned outages. 


Making the most of its decades of experience in manufacturing and managing low voltage to extreme high voltage levels, the Siemens portfolio offers highly reliable transformers, from distribution to HVDC transformers, with minimized risk of failure and maximized availability.

Investment pay-offs

Siemens power transformers come with strong investment security. State-of-the art transformer applications, such as variable shunt reactors, phase shifters, support customers in providing improved power quality. 


Operators can leverage Siemens transformers to increase capacity utilization and to optimize grid operation. A reactor, for example, can transmit more energy over existing lines, or a phaseshifter can be used to optimize load flow. Siemens not only builds retrofits with latest-technology transformers to replace old units but also offers interesting project financing solutions. 

Environmentally friendly

CO2 reduction

Replacing older applications with more powerful transformers using the latest technology substantially reduces the carbon footprint.


Ester insulation

Siemens offers both natural and synthetic environmentally friendly ester insulation for all transformers, including reactors, phase shifters, and HVDC applications.


Benefits of ester insulation

  • High flash- and fire point for increased safety
  • Readily biodegradable liquid for extended environmental protection
  • High moisture tolerance for a long lifetime
  • Possibility to increase transformer loading
  • Synthetic ester: low pour (-56°C) point allows operation in cold climates
  • Lower costs thanks to decreased risk of fire and longtime outages due to hazardous failures.

Certified quality standards

A strong Siemens transformer factory network around the globe creates leading transformer technology and pre-manufactured components. Siemens gobal footprint with transformers experts familiar with both local and international requirements also ensures customers enjoy fast response times and on-time delivery. In committment to quality without compromises, the quality management system used across all plants manufacturing Siemens power transformers complies to DIN ISO 9001:2000.


To meet public local content requirements, Siemens also enables and supports local transformer manufacturers to produce transformers based on Siemens technology. However, to ensure a consistently high transformer reliability, Siemens Transformers implements in-house prototype design and manufacturing.

Power Transformers

Areas of Application


Precision engineering enhanced by a modular feature architecture

Precision, utmost attention to detail and exacting standards in manufacturing ensure the high efficiency, long lifecycles, and low failure rates of Siemens power transformers.


Siemens' experience with custom-built units has led to a highly sophisticated design process that offers flexibility within a certain standardization frame while giving customers an economically efficient customization solution.


Siemens enhanced customization process offers additional advantages: Its highly-evolved modular architecture keeps manufacturing and maintenance efficient and cost saving.

Assembly & Testing: Manual work from the first to the last step

The core-and-coil assembly of the transformer consists of core, windings, tap switches, and connecting cables. Special attention is paid to the mechanical stability of the windings. A joint press ring for all windings on a core limb minimizes axial shear forces. The assembly dries under vacuum at 130 degrees Celsius. Bolted connections are tested and secured right after drying and just before the assembly is installed in the tank, even though, the assembly is still at a temperature of over 100°C. To ensure a long service life, the transformer is then filled with insulating oil.

Grid resiliency

Protecting the energy value chain

Maximum grid resiliency is a primary concern of all utilities and transmission operators worldwide. Siemens Transformers offers a portfolio of preventive, protective, and reactive measures for the entire energy value chain, from end to end.

A three-pilar plan for grid resilience

In collaboration with customers, Siemens Transformers has developed products and services that are at the same time reliable and flexible and provide any transformer operator peace of mind for their network. With cutting edge technologies, grid resiliency becomes a clear vision for the future of the energy industry. No matter if the grid is huge and urban or small and rural – the Siemens resilience portfolio PREVENT PROTECT REACT is adaptable for any utility. It offers solutions for all three groups of risk factors:

  • Operational issues such as network failures or aged fleet,
  • Natural disasters such as earthquakes, hurricanes, or geomagnetic storms,
  • Attacks, either physical or cyber attacks.

Visit our new grid resilience website

Mobile resiliency transformers keep outage duration short


Even slight deviations can make a big difference

A reliable power supply is key for business success in energy-intensive industries. Their risk management strategies typically range from alleviating the impact, reducing threat probability to transferring all or part of the threat to another party. The choice of strategy is based on the description of the risk they are dealing with. Mean time between failures (MTBF) is one key performance indicator in risk assessment.

Why calculating reliability matters

Manufacturers generally provide reliability indices – “Failure Rate” (FRe) as well as lists of MTBF – which are calculated using standard industry targets. But there is no “one-size-fits all” strategy to picking such targets. Calculating reliability indices and metrics is most useful when there is an actual target level of performance to be met. 


The average failure rate of a transformer changes over its lifetime. Even slight deviations can make a big difference – maybe not in the first years of service, but surely further ahead in its lifecycle. Incorporating reliability indices in a congruent risk management framework is crucial to business success, and it is important to consider the limitations of risk indices. Siemens Transformers supports customers in understanding and calculating reliability, not least because their transformers have a unique track record of high reliability, from in-time delivery to safety, from quality of product to transparent contacts and support


Download: "Siemens Transformers: External failure rates for Power Transformers"

Service - Strategically increase value with Transformer Lifecycle Management

Transformer Lifecycle Management™ (TLM™) is a service concept for all transformers in your network, regardless of age, manufacturer, or power. It lets you plan expenditures and control the timing of new investments. It helps to avoid unplanned outages and minimize planned downtimes. And TLM™ supports you in reducing your environmental footprint while maximizing transformer availability.

We bring transformer service to you

Your transformers need to operate reliably and without interruption. Siemens' TLM™ service concept helps you make the most of your fewer and increasingly shorter windows of opportunity even for planned service interruptions. The TLM™ answer to the problem are technologies and methods that are as mobile as our experts. From oil-drying systems to high-voltage testing stations, TLM™ mobile repair workshops support you on-site. They complement the services provided by the Siemens’ repair facility – they’re fast, flexible, and can be integrated in your operations.

Manufacturing - A global network

We manufacture Siemens power transformers in a total of 14 transformer factories on four continents. Each one of these production plants has a different focus in terms of research and development. Our network of factories ensures that our customers worldwide profit from the special skills and solutions of all individual locations. Quality is always to European standards, regardless the manufacturing location.    

Customer advantages

  • Prompt preparation of bids
  • Optimized, consistent end-to-end project management
  • Noticeably shorter production and delivery times
  • Very high delivery reliability
  • Flexibility and reliability thanks to backup factories
  • Fast, standardized documentation
  • Just-in-time delivery

Harmonized design, globally standardized design guidelines, and standard IT programs for all plants ensure that our customers always receive the best possible product, no matter which Siemens factory they purchase it from.

Success stories and case studies

Learn more about latest applications of Siemens’ power transformers

Downloads & support

Learn about our products, services and support

Contact the Energy Support Center

Energy Customer Support

+49 180 524 70 00

+49 180 524 24 71


Freyeslebenstraße 1

91058 Erlangen



Making a difference

Siemens power transformers are bult in 14 plants in various countries for operation all over the world. Financial investment pay-offs manufacturing quality certified: DIN ISO 9001:2000, built to comply national and international standards according to customer needs, excellent customer service wherever you are.

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Find out more about the benefits of a tailored-to-fit Siemens solution

Contact our Energy Support Center


Get in contact with our Sales Support and Customer Service for Power Transmission and Distribution

Do you need help on a concrete project? Do you need a quote for any of our products or solutions? Do you need support for your installed equipment? Do you have a technical question? Do you need something totally different? You can contact us 24/7. We are looking forward to your call or online request. Phone +49 180 524 70 00