CAJ | 학술논문

海上风电经分频输电线路传输的研究近年来引起国内外的关注。由去除机端换流器的多台基于永磁直驱同步发电机(PMSG)的风电机组、海底电缆和交交变频器组成的分频海上风电系统，可通过线路末端的交交变频器控制PMSG的转速捕获风能，可节省初始投资和运行维护费用。考虑变压器和输电线路的影响后，推导出分频海上风电系统的准稳态模型，基于转子平均磁链定向给出多机矢量控制器的设计原理；从曲线拟合的角度，给出多机组运行频率的求解方法；以4台PMSG为例，搭建了分频海上风电系统仿真模型。结果表明采用多机矢量控制方法，在不同风速条件下，风电机组的转速均能够跟随指令值，并实现风能的最优捕获。
해상풍전경분빈수전선로전수적연구근년래인기국내외적관주。유거제궤단환류기적다태기우영자직구동보발전궤(PMSG)적풍전궤조、해저전람화교교변빈기조성적분빈해상풍전계통，가통과선로말단적교교변빈기공제PMSG적전속포획풍능，가절성초시투자화운행유호비용。고필변압기화수전선로적영향후，추도출분빈해상풍전계통적준은태모형，기우전자평균자련정향급출다궤시량공제기적설계원리；종곡선의합적각도，급출다궤조운행빈솔적구해방법；이4태PMSG위례，탑건료분빈해상풍전계통방진모형。결과표명채용다궤시량공제방법，재불동풍속조건하，풍전궤조적전속균능구근수지령치，병실현풍능적최우포획。
Offshore wind power integration via the fractional frequency transmission system (FFTS) has in recent years drawn attention worldwide. The fractional frequency offshore wind power system consisting of paralleled-connected multi-pole permanent magnet direct-drive synchronous generators(PMSGs),subsea cable,and an onshore cycloconverter possess a number of advantages.In this system,the cycloconverter is used to control the rotating speed of the wind turbines to harvest maximum wind power,and the generator-side converters of PMSGs are no longer needed to reduce the investment and operation and maintenance cost.A quasi-steady-model for fractional frequency offshore wind power system considering the influence of transformers and transmission lines is presented.In addition,a control scheme based on average rotor flux orientation is demonstrated.The multi-machine optimal speed can be obtained via curve-fitting.Furthermore,a simulation model for a fractional frequency offshore wind power system with four PMSG based wind turbines is developed.Simulation results show that the rotating speed of PMSG based wind turbines is able to follow the reference very well under various wind conditions,while the proposed system structure can harvest optimal wind energy.