海上双馈感应发电机定子绕组匝间短路容错技术可行性分析

受海洋恶劣环境影响,海上双馈感应发电机(DFIG)定子绕组匝间短路故障频发,伴随海上可及性差引起的故障维修困难、停运损失巨大,使得容错技术需求日趋迫切。文中根据DFIG定子绕组匝间短路故障特点,构建精确通用的定子绕组匝间短路模型。针对故障后定子电流负序分量幅值增大而严重影响DFIG正常运行的问题,分离各序分量并提取定子负序电流,通过在转子侧输入相应的谐波电压来抵消定子侧负序电流,构建负序电流控制器以抑制故障后定子相电流的负序分量。仿真与实验结果验证了该方法可以有效降低DFIG定子绕组匝间短路故障后的定子负序电流幅值与输出功率脉动。

Feasibility Analysis of Fault-tolerant Technology for Stator Winding Turn-to-turn Short-circuit Fault of Offshore Doubly-fed Induction Generator

Owing to the harsh marine environment, the stator winding short-circuit faults of offshore doubly-fed induction generator(DFIG)occurr constantly. Due to the low accessibility, the problems of hard maintenance and high outage loss in the offshore wind farm make the fault-tolerant technology requirements increasingly urgent. The precise and generic stator winding turn-to-turn short-circuit model of DFIG is built based on the short-circuit fault characteristics of DFIG stator windings. To solve the problem of the operation for DFIG which is seriously affected by the increase of stator negative sequence current during the fault of sequence current is seperated and the negative sequence current is extracted and offsetted by injecting the corresponding harmonic voltage into the rotor side, and the negative sequence controller is built to restrain the negative component of the stator phase current after the fault. The simulation and experimental results indicate that the proposed method is able to reduce the amplitude of stator negative sequence current and pulsation of output power.