Comparison of power conversion topologies for a multi-megawatt off-shore wind turbine, based on commercial Power Electronic Building Blocks

Abstract

This paper presents a comprehensive comparison of five commercially viable configurations to achieve a wind turbine conversion system of 6 MW, suitable for off-shore applications. These comprise Full Converter (FC) and Doubly Fed Induction Generator (DFIG) types with several redundancy levels. The power conversion lines are implemented using standard Power Electronic Building Blocks (PEBB) or Basic Power Modules (BPM) that allow a wide range of combinations. The BPMs use Insulated Gate Bipolar Transistor (IGBT) technology of either, Low Voltage (LV) or Medium Voltage (MV) levels. The options are described in the paper, and are compared against several key features such as output voltage, price, volume, weight, power density, semiconductor supply chain, grid-side filter, overall supply chain, efficiency, grid code compliance, redundancy, cooling and maintenance. The generator technology is also considered in the study.