中文摘要：

风电系统在电网电压跌落情况下的持续能力直接影响电网对风电的消纳能力和风电场的经济效益,因此研究其低电压穿越能力具有重要的意义。针对永磁风力发电系统中的背靠背电压型脉宽调制变换器存在直流大电容,在电压突降时会引起变换器的直流母线电压升高的情况,提出了采用双级矩阵变换器取代背靠背电压型脉宽调制变换器的永磁风力发电系统。在分析双级矩阵变换器已有控制方式不稳定的基础上,采用了一种加入修正项的新型控制方法,并采用根轨迹法证明其稳定性,最后通过Matlab/Simulink软件仿真验证了上述方法比已有方法具有更强的低电压穿越能力,实际硬件电路实验也验证了所提方法的正确性和可行性。

英文摘要：

In case of grid voltage sags, sustainable capacity of wind power system directly affects capacity of power grid accommodating wind power and economic benefit of wind power generation, so it is important to study capability of low voltage ride through. In view of large DC capacitance of backto-back voltage-source pulse-width modulation converter for permanent magnet wind power generation system, DC bus voltage of the converter will increase suddenly at voltage drop. New permanent magnet wind power generation system is proposed in this paper, using two-stage matrix converter to replace back-to-back voltage-type pulse-width modulation converter. On basis of analyzing instability of original control mode of two-stage matrix converter, a new control method is added as correction term, and its stability is proved with root locus method. Finally, simulation results on Matlab/Simulink show that the proposed method has better capability of low voltage ride through than existing methods, and actual circuit experiments also verify correctness and feasibility of the proposed method.