A high-power DC-DC converter based dual active bridge for MVDC grids on offshore wind farms

Abstract

A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. AbstractThis paper presents the steady-state analysis of a high power step-up DC-DC converter based threephase dual active bridge (3DAB) for use as a medium voltage (MV) DC-DC collector of offshore wind farms. An optimization procedure for a high-power medium frequency transformer is explained and moreover, a design of an optimal control phase shift angle is explained and verified through simulation. The comparisons with two scenarios are presented: 4MW converters for power conversion from low dc voltage (LVDC) of the wind turbine output terminal to 40kV MVDC grid of offshore wind farms. The proposed 3DAB DC-DC converter is investigated for the given scenarios in terms of losses of the semi-conductors and the magnetic part as well as the quantity of semi-conductors.

Design considerations for a high-power dual active bridge DC-DC converter with galvanically isolated transformer

“…The sizing of the snubber capacitor can be carried out by the initial maximum turn-off current conditions in an ideal snubberless converter circuit. Maximum turn-off currents on primary and secondary side converter in case of ideal snubberless 3DAB Converter under the condition that the phase shift angle range is limited to ) 60 ( 3°≤ π ϕ can be calculated using ( 1) and ( 2) [11]…”

Novel multi‐terminal MMC‐based dc/dc converter for MVDC grid interconnection

“…Medium-voltage direct-current (MVDC) grids have been the focus of numerous research studies in recent years due to their increasing applications in rapidly growing grid-connected renewable energy systems, such as wind and solar farms [1][2][3][4]. Due to higher efficiency and flexibility, the MVDC systems are being considered as alternatives to ac networks in electrified transportation systems, such as electric shipboards and aircrafts [5].…”

“…Modular multilevel converters (MMCs) have emerged as the most promising topology for medium-voltage high-power applications [8]. MMC-based dc/dc converters are employed for collecting power from offshore wind and wave farms, the point-topoint connection of similar or different voltage levels in MVDC grids and controlling power flow in such networks [1][2][3][4][5][6][7]. Among various developed dc/dc converter topologies, MMC-based dc/dc converter with medium-frequency (MF) transformer, which is also known as isolated MMC-based dc/dc converter (IMMCDC), is a promising topology due to its numerous advantages [2,6,9,10].…”

An analytical modeling and estimating losses of power semiconductors in a three-phase dual active bridge converter for MVDC grids

“…Until now, many DC-DC converter topologies have been presented in different industries such as automotive industry, more electric aircraft (MEA), renewable energy sources, and DC grid collectors. 3DAB Converter which is suitable for high-power application has been studied in [4]- [7] and [9]. Besides, 3DAB converter offers a higher power capability and smaller passive filtering parts compared to single-phase dual active bridge (1DAB) type.…”