基于组合保护方案提高DFIG低电压穿越能力的仿真分析

电网故障导致电压跌落时,大容量风电场中风机的相继切出会影响系统运行的稳定性。为保证电网安全可靠运行,风力发电机组的并网导则要求目前广泛应用的双馈感应发电机（DFIG）具备低电压穿越（LVRT）能力,即确保电网电压跌落情况下DFIG保持不脱网运行。本文在深入分析传统Crowbar保护电路的基础上,针对其不足提出了组合保护方案并给出了相应的控制策略。基于Matlab/Simulink平台建立了风电场并网运行仿真模型,仿真结果表明所提组合保护方案能够有效提高DFIG的低电压穿越能力。

Study on Low Voltage Ride Through Capability for DFIG Based on Combination Protection Scheme

If wind turbine in large scale wind farms cuts out successively due to voltage drops caused by power failure,system stability will be affected.To ensure the safety reliability of power grid,it is required that the widely used double-fed induction generator（DFIG） should have low voltage ride through（LVRT） capability,which means DFIG should remain on during the low voltage.On the basis of analyzing traditional Crowbar protection circuit in depth,the combination protection scheme and corresponding control strategy are proposed in this paper.Simulation model of wind farm connected to grid is built by Matlab/ Simulink platform,simulation results show that the proposed combination protection scheme can effectively improve the low voltage ride through capability of DFIG.