CAJ | 학술논문

当前国内外对于风电机组的并网规范都要求电网发生电压跌落时风电机组能够保持不脱网运行以帮助电网故障恢复。针对一种新型的基于多相直驱永磁同步发电机（PMSG）和混合式三电平变流器的大功率直驱风电系统的低电压穿越技术进行了研究。首先分析了电网故障对直驱风电系统带来的影响，然后给出了新型机组的低电压穿越策略，即通过改变电机侧和电网侧变流器的电流给定，配合发电机转速调节的方法来控制系统的能量传输，进而达到穿越故障的目的。最后建立了所提出的风电系统的时域模型，给出了不同电网故障情况下的仿真结果，验证了控制策略的可行性和有效性。
당전국내외대우풍전궤조적병망규범도요구전망발생전압질락시풍전궤조능구보지불탈망운행이방조전망고장회복。침대일충신형적기우다상직구영자동보발전궤（PMSG）화혼합식삼전평변류기적대공솔직구풍전계통적저전압천월기술진행료연구。수선분석료전망고장대직구풍전계통대래적영향，연후급출료신형궤조적저전압천월책략，즉통과개변전궤측화전망측변류기적전류급정，배합발전궤전속조절적방법래공제계통적능량전수，진이체도천월고장적목적。최후건립료소제출적풍전계통적시역모형，급출료불동전망고장정황하적방진결과，험증료공제책략적가행성화유효성。
In the case of grid voltages dips, the wind power plants are demanded to keep connected to the grid, and to help the network recover from the fault. This paper focuses on the low voltage ride through （LVRT） control of large-scale wind energy system based usinga multiphase direct drive permanent magnet synchrony generator （PMSG） and three-level converters. The paper analyzes the impact of generator side rectifiers and grid side converters cased by symmetrical or asymmetrical voltage dip. In order to fulfill the LVRT requirement, the energy accumulated in the converters has to be reduced. A control approach is developed, which is implemented by resetting current command and adjusting the speed of PMSG. Finally, a time-domain computer simulation is done for the proposed system. Simulation results confirm the feasibility and validity of the proposed method.