定桨失速型风电机组在电网短路故障时的暂态分析

Transient Analysis of Fixed Pitch Stall Wind Generating Set at Shorted Fault of Power Network

以WD750型定桨失速风力发电机组为研究对象,通过分析异步电机定子侧等效电路阻抗与转差的关系,给出了异步电机次暂态电抗的计算方法,并对该机组在电网故障时的暂态电流进行了理论计算和仿真实验。分析结果表明:定桨失速型风电机组在电网发生短路故障时的暂态电流短时非常大,峰值大约为额定电流的12倍左右,大约0.2s后衰减至零,并且理论计算的峰值比仿真结果略大。因此,风电机组中需加装Crowbar等保护电路以消除电网故障引起的暂态不利影响。

With model WD750 fixed pitch stall wind generating set as a study object, via analysis on the relation between asynchronous motor stator side equal effective circuit impedance and slip, calculation method of asynchronous motor subtransient impedance was given, and theoretical calculation and simulation experiment for the transient current of the generating set at power network fault were carried out. Analysis result shows that at power network fault, the transient current of fixed pitch stall wind generating set is very large in short time, the peak value is about 12 times of rated current and after 0.2 seconds, the current attenuates to zero, also a little bit larger in theoretical calculation than that of simulation result. Therefore there is a need to additionally install crowbar ete protection circuits so as to eleminate unfavorable transient impacts caused by power network fault.