基于超级电容器储能的双馈风力发电机低电压穿越研究

Study on the low voltage ride through of doubly fed wind generator based on the supercapacitor storage

针对双馈风机低电压穿越过程中直流侧过电压以及系统动态无功支撑问题,提出了一种基于超级电容器储能的双馈风力发电系统低电压穿越方案。建立了新的双向DC-DC变换器和网侧变换器控制策略,并通过构建模型进行系统仿真。仿真结果表明,该方案在故障过程中能有效地抑制直流侧过电压,并能由网侧变换器向电网提供无功功率,支持电网恢复,提高了系统的低电压穿越能力。

Aiming at the problem of the DC-link overvoltage and the dynamic reactive power supply in the low voltage ride through （LVRT） of the doubly fed induction generator （DFIG） wind turbine system, this paper proposes a LVRT scheme of DFIG based on the supercapacitor storage. The novel control strategy for the bi-directional converter and the grid side converter is established. Simulation model of the DFIG system is developed. Simulation results show that the presented scheme can efficiently reduce the DC-link overvoltage, supply reactive power to the power system through grid side converter, help grid recovery under system fault, and improve the LVRT capability of the system.