具有低电压穿越能力的双馈风电机组故障特性及影响因素分析研究

Study on Failure Characteristics and Influencing Factors of Doubly-fed Wind Turbine with Low Voltage Ride-through Capability

在PSCAD平台下构建了具有低电压穿越能力的双馈风电机组模型,仿真分析了不同低电压穿越模式下的机组穿越特性和故障特性,并仿真验证了上述影响因素对机组故障电流的影响。指出传统转子Crowbar电路的投入是机组故障电流频率为非工频的原因,而采用其他非转子Crowbar电路的机组故障电流频率为工频;风电场联络线发生任何类型的不对称接地故障,风电场侧都会表现出弱电源特性,单相接地故障表现出的弱电源特性更为明显。在风电场保护配置和整定时需考虑上述因素的影响。

The model of doubly-fed wind turbine with low voltage ride-through capacity is built based on PSCAD platform, and then the ride-through and failure characteristics under different low voltage ride-through mode are simulated and the impacts of above factors on fault current of unit are verified by the simulation. The reason that the fault current is non-frequency is putting traditional rotor Crowbar circuit into operation, but when other non-rotor Crowbar circuit is used, the fault current frequency will be in normal working state. The side of wind farm will show weak power characteristics when the contact line of wind farm occurs any type of asymmetrical ground fault, specially under the condition of single-phase ground fault. In wind farm protection configuration and setting, these influencing factors need to be considered.