Establishment of functional requirements to DC-connected wind turbine and their use in concept selection

Offshore wind farms using medium voltage DC power collection promise an increase in efficiency and a reduced bill-of-material cost. One of the key components is the high power, medium voltage DC/DC converter located in the wind turbines. There are many suggested topologies in the state of the art, but they are all still at an immature technology level, as no substantial experience from full-scale detailed design exists. By employing a functional failure mode and effects analysis (F-FMEA) with a decision making tool (Pugh Matrix), the paper presents a structured set of functionalities and design drivers required from the turbine DC converter and uses these to compare 6 distinct candidate circuit topologies. The end goal is not to select the best topology, but to narrow down from a vast list of options and give a method that will increase confidence and guide towards the characteristics of reliable design.