Largest HVDC VSC transformer ever built on its journey to China from Sweden

Large transformers are regularly produced and deployed from the Hitachi Energy factory in Ludvika, Sweden, but one special unit marks a milestone.

In a historic moment for the transformers team, the largest HVDC VSC transformer ever built officially left the building and began its journey across continents, carrying Hitachi Energy's long legacy of transformer technology and innovation.

It is the largest high-voltage direct current (HVDC) voltage sourced converter (VSC) transformer ever manufactured – unmatched in power, size, and weight. Built with 750 mega volt-ampere (MVA) capacity and technology for ±800 kilovolt (kV), it will be a critical part of one of the world’s most advanced HVDC projects in China. The Gansu–Zhejiang ±800 kV Ultra UHVDC VSC Transmission Project is expected to deliver more than 36 billion kWh of electricity per year to Zhejiang province, meeting the annual electricity demand of about 10 million households. This breakthrough transformer, manufactured at the Hitachi Energy Ludvika factory, is a testament to our unmatched expertise and decades of experience as the world’s largest transformer manufacturer.

Building the transformer was one challenge; the journey to China turned into an exceptional story of its own.

With a total transport weight of 820 tons, including the vehicle, this was the heaviest transport ever to leave Ludvika. The factory is well known for its capability to deliver very large units; however, due to its weight, this particular unit exceeded the limits for rail transport. The team mapped a road route from Ludvika to Köping, then onto a barge bound for the port of Norrköping, and by sea toward Shanghai. Indeed, the journey is as remarkable as the transformer it carries.

Logistics, planning, and coordination took more than a year. Authorities, transport partners, engineers, and logistics specialists worked side by side to make sure each step happened with precision – exactly when and how it needed to.

The transport of the HITACHI-branded transformer is already underway, steadily making its way toward Shanghai, where it is expected to arrive in mid‑2026.

This milestone is proof of what can be accomplished through strong collaboration with partners and the entire team at Hitachi Energy Transformers – from sales, project management, design, production, quality, purchasing, logistics, testing, packaging, and technical support. Every single effort is critical to moving this project forward.

“This significant transformer project reflects the commitment, cooperation, and professional pride of hundreds of colleagues to deliver impact to enable sustainable progress and the era of electricity,” adds Markus Pettersson.

Extending beyond Sweden, the company’s close partnership with the Swedish Transport Administration, local authorities, contractors, security personnel, and the transporter company made this historic move possible.

This transformer unit will serve as the reference transformer for a total of seven identical units to be manufactured in China, with on-the-ground support from Ludvika employees sharing their knowledge and experience.

The transformer unit’s journey from Ludvika to Shanghai continues, marking just one chapter in Hitachi Energy’s HVDC transformer technology story.