HVDC transformers are used for self-commutated voltage-sourced converters. Siemens delivers HVDC Plus Converter transformers for transmission lines up to 1,200 MW, up to 500 kV DC with connections to AC grids up to 525 kV.
In HVDC Plus mono-pole applications, no DC voltage stresses occurs at the transformer valve terminals. In HVDC Plus, bi-pole applications the valve windings which are connected to the HVDC Plus rectifier/converter circuit are subject to the combined load stress of DC and AC voltage. The harmonics content of the operating current is much lower than in HVDC Classic applications. It usually meets grid code requirements. Additional DC currents on the valve and/or neutral terminals have to be considered. They are much lower than in HVDC Classic applications.
As a world-leading manufacturer, systems integrator, and provider of transformer solutions and services with a strong local presence, Siemens experts are there wherever and whenever you need them to assist, consult, and provide service. The lead center in Nuremberg ensures that the same extensive know-how and the same technology and quality are available to our customers around the world, while four HVDC facilities across the globe can keep distances for transport to a minimum.
Hundreds of Siemens HVDC Converter transformers are in successful operation all over the globe. Active in the field since the 1970s, Siemens Transformers has huge experience in designing and manufacturing HVDC units. Rising to challenges, from in-time delivery for large order volumes to building record-setting units that meet highest technical specifications, Siemens stands out for trademark reliability and customer focus.
In the long history of transformers, HVDC transformers are quite a young chapter. The innovation path of this product is more like an innovation highway: The units are becoming more powerful at the same or an even more compact size.