全功率变流器永磁直驱风电系统低电压穿越特性研究

随着风电机组安装容量的不断上升，风电系统在电网故障情况下的运行变得尤为重要，电网导则要求风电机组在电网电压瞬间跌落一定范围内不脱网运行。针对使用背靠背全功率变流器的永磁直驱风电系统，提出一种在电网电压瞬间跌落情况下不脱网运行的方法。电网发生电压瞬间跌落时，网侧变流器运行在静止无功补偿（STATCOM）模式，依据电网电压跌落的深度决定发出无功电流的大小，通过快速提供无功电流来稳定电网电压，实现直驱型风电系统的低电压穿越功能。仿真和实验结果表明电网电压故障时使直驱风电系统运行在STATCOM模式可以有效提高低电压穿越能力。

Studies on the Low Voltage Ride Through Capability of Fully Converted Wind Turbine with PMSG

With the increase of wind turbine installation, the behavior of wind power system during grid disturbances becomes very important. Grid codes require that wind turbines stay connected to the grid during voltage dips for a certain period. A control method is proposed to keep direct-driven wind power system with back-to-back full power converters using permanent magnet generator connected to the grid during voltage sags. When voltage sags happen, the grid-side converter operates in the STATCOM mode and export reactive power to maintain the wind turbine terminal voltage. Simulation and experimental results illustrate that the method can effectively improve the direct-driven wind power system low voltage ride through capability.