基于低电压穿越的风电场集电线路短路电流研究

Short Circuit Current of Collector Lines in Wind Power Plant Based on Low Voltage Ride Through

为了提高风电场集电线路短路电流的计算精度,研究低电压穿越的短路故障暂态机理,分析低电压穿越全阶段双馈感应发电机的短路电流计算公式,通过等值简化得到集电线路短路电流计算公式,进一步分析影响集电线路短路电流的主要因素;利用电磁暂态仿真软件PSCAD/EMTDC进行算例仿真分析,研究集电线路不同位置故障与风电场集电线路短路电流间的关系。结果表明,故障点越靠近中压集电点母线,电压跌落越严重,集电线路短路电流暂稳态值越大,且故障线电流对短路点电流的贡献要比非故障线大10倍左右。

To improve the calculation accuracy of short circuit current of collector line in wind power plant,the short circuit fault transient mechanism of low voltage ride through was studied,and the formula for calculating the short circuit current of double feed induction generator of low voltage ride through full stage was analyzed.The calculation formula of the short circuit current of the collector line was obtained by the equivalent simplification,and the main factors affecting the short circuit current of the collector line were further analyzed.Electromagnetic transients software PSCAD/EMTDC was used in simulation analysis of an example,and the relationship between the faults of different positions of the collector line and the short circuit current of the collector line of the wind power plant was obtained.The results show that the closer the fault point is to the bus of point of common coupling,the more serious the voltage drop is,and the greater the transient steady state of the short-circuit current of the collection line is.The contribution of the current of the fault line to the short-circuit current is about 10 times greater than that of the non-fault line.