A Study on Modular Multilevel Converter based Wind Turbine Generator Connected to Medium Voltage DC Collection Network

摘要

This study proposes an application of Modular Multilevel Converter (MMC) to wind turbine direct driven Permanent Magnet Generator (PMG) which is connected to medium voltage DC collection network. The topology, modeling, operation, and control method of the wind turbine generator connected to MMC system are presented. The aim of the application of MMC to the wind turbine generator is to increase its operating voltage so as to be connected to medium voltage of DC network. Besides that, a grid side converter, a harmonic filter device and a transformer of the wind turbine generator can be neglected. Feasibility and validity of operation and control method of the proposed MMC based wind turbine generator have been investigated through simulation study. The simulation is performed by using PSCAD/ EMTDC package program. The obtained results have confirmed that the proposed topology and control system have good dynamic performance, controllability, and reliable stability.