The Journal of Engineering (Oct 2018)
Impacts on operational characteristics of AC/DC system with different grid integration modes of offshore wind farm via MMC-based HVDC transmission
Abstract
With the rapid development of renewable energy resources, wind power plays a major role to support the conventional power system. Meanwhile, the module multilevel converter (MMC) technology attracts the public's wide attention in the implementation of offshore wind farm integration. To analyse the impacts on the operational characteristics of hybrid AC/DC power system, the simulations and relevant remarks with grid integration of large permanent magnet synchronous generator (PMSG)-based wind farms using different MMC-based HVDC transmission structures are conducted. First, the detailed mathematical models and control strategies pertinent to PMSG and MMC are introduced, respectively. By applying different MMC-based HVDC topologies of offshore wind farm integrating into the AC power grid, the interactions between DC system and AC grid can be elaborately studied via changing the wind speed conditions, the wind farm point of common coupling etc. under the PSCAD/EMTDC^™ simulation environment. Furthermore, the wind power penetration level is also analysed. A modified 4-generator 2-area hybrid AC/DC test system is applied as benchmark to carry out the corresponding simulation studies. Some useful and significant conclusions and comments are drawn.
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