A Novel Oil-immersed Medium Frequency Transformer for Offshore HVDC Wind Farms
Artikel i vetenskaplig tidskrift, 2021

Offshore wind farms pose the challenge of transmission of produced energy in an economic and effective way over long distances, justifying investments in High Voltage Direct Current (HVDC) systems. A solution to surmount the need for an expensive and large power transformer station is to connect each wind turbine to a DC/DC converter in which a Medium Frequency Transformer (MFT) is utilized to reduce the size of the station. Further, the DC outputs of the converters of the wind turbines can be connected in series to create a high DC voltage. In this solution, the MFTs are required to be insulated
against a high DC voltage to ground in a limited compartment. This contribution presents a prototype of a 50 kW oil-paper insulated MFT operating at biased 422/4500 V/V AC 5 kHz and 125 kV DC test voltage, which has been manufactured and subjected to verification HV tests. The dielectric design of the prototype MFT based on finite element solution of non-linear Maxwell-Wagner equations is introduced and the acceptance criteria and practical design considerations are discussed.

HVDC insulation design

finite element analysis

medium frequency transformer

prototype design methodology

DC-DC power converters

Wind energy


Mohammad Kharezy

RISE Research Institutes of Sweden

Hassan Reza Mirzaei

University of Zanjan

Yuriy Serdyuk

Chalmers, Elektroteknik, Elkraftteknik, Elnät och komponenter

Torbjörn Thiringer

Chalmers, Elektroteknik, Elkraftteknik, Elmaskiner och kraftelektronik

Morteza Eslamian

University of Zanjan

IEEE Transactions on Power Delivery

0885-8977 (ISSN)


Hållbar utveckling

Innovation och entreprenörskap




Grundläggande vetenskaper


Elektroteknik och elektronik




Mer information

Senast uppdaterat