双馈风力发电机故障电流特性的仿真研究

The simulation research on the characteristic of fault current of doubly-fed induction generator

为构建含有风电机组的新型配网保护系统，在考虑电机的控制系统和杠杆保护影响的情形下，对双馈风力发电机的三相故障短路电流进行研究．首先分析了短路电流可能含有的故障分量，给出其解析表达式；然后建立电机本体、杠杆保护和功率控制模型，仿真出各种故障程度下故障电流波形．实验结果表明：故障电流波形具有多态性，即线路近端故障时，电机故障电流稳态晤值小于额定电流；线路远端故障时，电流幅值为额定电流的2～3倍，与传统同步电机的恒定稳态故障电流波形存在较大差异．

In order to construct the protection system of new distribution which was interconnected the wind power generators, this paper made a research on the short-circuit current of doubly-fed induction generator （DFIG） based on considering the impact of generator control system and crowbar protection. This article theoretically analyzed the fault components contained in the current and presented the mathematic expression of the current. By establishing the generator model, specific rotor-side exciting decoupled control system and active crowbar protection, the multi-waveforms of fault current were presented under various degree of three phases short-circuit faults. The results show that current waveform has multi-forms characteristic. The near terminal steady-state fault current amplitude is less than the rating current and in contrast the remote fault current is 2-3 times to the rating current. That is very different from the conventional synchronous generator.