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Transformers with TVP® Technology

Hitachi Energy's Transformers with TVP® Technology

Welcome to the Future of Transformers Reliability!

At Hitachi Energy, we have pioneered a groundbreaking solution designed to safeguard your transformers like never before – Transformers with Transient Voltage Protection (TVP®) Technology.

After successfully installing 2500 units of dry-type transformers in diverse applications and geographical regions with TVP® technology over the past 7 years, with no known field failures, Hitachi Energy has expanded the TVP® technology to liquid-filled transformers too.

Elevate your distribution transformers to new heights of reliability and resilience.

Watch the film to learn more.

Why is protection from transient voltage important?

If your processes require a lot of electrical network switching or if your electrical networks are causing a lot of nuisance tripping, then your transformers are at risk of premature failure due to switching transients - that would result in a costly outage. 

Medium voltage, fast-acting circuit breakers like Vacuum Circuit Breakers (VCBs) pose a unique and pressing concern across industries: transient voltage.

While Vacuum Circuit Breakers (VCBs) have incredible arc-quenching capabilities that bring increased safety and efficiency to electrical systems, in certain system configurations and procedural operations, VCB (and SF6) switching can produce fast transient overvoltages inside of transformer windings, some leading to failures. These failures result in system downtime and irreparable equipment, both incredibly costly to network managers.

For an in-depth understanding of the threat from transient voltage, please visit the blog post on The Hidden Threat:  Transient Voltage

The only perfect solution: Hitachi Energy’s Transformers with TVP® technology


Transformers with Transient Voltage Protection (TVP®) Technology by Hitachi Energy provide complete protection for your electrical systems at every single switching instance. Their network-agnostic design makes them the best fit for you, no matter what your network configuration is or how often switching operations are performed.

Hitachi Energy's Transformers with TVP® Technology

Our transformers equipped with TVP® have varistors strategically integrated into the transformer windings to enhance the coil technology. Their location protects coils from both reignitions and resonance amplification during switching events, thereby completely eliminating the risk of any damage from sudden transient peaks and subsequent costs of downtime and repair/replacement.

Hitachi Energy's Transformers with TVP® Technology

Figure 1: Worst-case switching scenario of a 20kV Dry type transformer

The waveforms in Figures 1 and 2 below represent actual laboratory testing, representing worst-case switching scenarios for 20kV Dry type and liquid-filled transformers. It is evident from these charts that TVP® limits transient voltage peaks to a controlled, predictable level that is safe for the transformer.

Hitachi Energy's Transformers with TVP® Technology

Figure 2: Worst-case switching scenario of a 20kV liquid filled transformer

What makes TVP® stand out from other available solutions?

Optimal solution

  • As TVP® works in all system configurations, no complex and time-consuming system is required
  • Competitive solution over RC snubber
  • Does not alter the transformer footprint
  • TVP® solution comes inbuilt with Hitachi Energy Transformers and does not require any additional maintenance- no site installation hassle for customers/end users.

Full protection

  • TVP® is the only solution that limits transient voltages to a controlled, predictable, safe level.
  • It protects transformers and downstream equipment from both reignitions and resonance over-voltages.

Proven field record

  • ~2,500 units of TVP® equipped Hitachi Energy Dry-type transformers operating in the field for over 5 years.
  • No field failure was reported.
  • Proven for a diverse range of applications such as Datacenter, Industries, Rail Infrastructure, mainstream, etc.

Why Choose Hitachi Energy's Transformers with TVP® Technology?

Proven Reliability

For the past decade, Hitachi Energy has been at the forefront of innovation, producing Dry-type Transformers with TVP® technology. ~2500 units are operating globally, demonstrating unparalleled reliability with zero failures.

Extended expertise

With over a century of experience in transformer technology, Hitachi Energy stands as a global leader. Our legacy of innovation and commitment to excellence ensures that you receive not just a product but a reliable solution backed by a trusted industry expert.

Unparalled in the industry

No other solution can offer the level of protection that Hitachi Energy’s Transformers with TVP® brings. Besides, these transformers with TVP® are the most optimum solution. Please see more details below.

Scope for TVP® Technology:

TVP® for Dry-type transformers

Available for Hitachi Energy's Vacuum Cast Coil and Resibloc Dry type transformers

TVP® for Liquid-filled distribution transformers

Available for pad-mounted, ground-mounted, and substation-type transformers

Understand risk of transient voltages to transformers in key applications with these short-stories

Transformers in certain applications, such as below, are particularly at higher risk of getting damaged due to switching transients, and it is highly recommended to assess the risk and provide suitable protection like Transformers with TVP® to avoid potential failure and subsequently costly downtime and loss of revenue. 

Data Center

Solar Power

Rail & Industry

Wind Power

Resources for In-Depth Understanding:

Part of categoryBlog Post
03-11-2023 | 5 min read

Risk of Transient Voltage

Explore the detailed explanation of transient voltage risks and their impact on transformers.

Product Brochure

Explore the detailed features and specifications of our Transformers with TVP® Technology.

[CIRED 2023] TVP-Liquid Immersed Distribution Transformers Protection Against Fast Transients

Delve into the complexities of transient voltage and understand how our technology provides a comprehensive solution.

[IEEE Xplore] Efficiency of surge arresters as protective devices against circuit breaker induced overvoltages

Delve into the complexities of transient voltage and understand how our technology provides a comprehensive solution.

[IEEE Xplore] Effect of different types of over voltage protective devices against vacuum circuit breaker induced transients in cable systems

Delve into the complexities of transient voltage and understand how our technology provides a comprehensive solution.

power plant engineer for substation

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