Analysis on the operation of crowbar in doubly fed induction generators
Analysis on the operation of crowbar in doubly fed induction generators
复制标题
双馈感应发电机撬棒的运行分析
DOI：
10.1016/j.epsr.2022.108950
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发表时间：
2023
影响因子：
3.9
通讯作者：
Liu Kang-Zhi
中科院分区：
文献类型：
--
作者：
Onishi Koji;Li Yingxiao;Koiwa Kenta;Liu Fang;Zanma Tadanao;Liu Kang-Zhi
撬棍是一种常用的用于双馈感应发电机（DFIG）故障穿越的装置，它可以保护电源变换器不受过流/过电压的损坏。一旦检测到过流/过压，撬棍就会被激活，为了向电网输出有功/无功功率，需要尽快释放撬棍。但在不适当的时间释放撬棍可能会导致过电流的再次发生。因此，在适当的时机释放撬棍是很重要的。为此，我们分析了转子电流的行为，并揭示了电流幅值的周期性波动与衰减幅度。因此，有一组释放时间可以防止过流/过压。此外，这些释放时间对电压下降深度、发电机参数以及风速的变化具有鲁棒性。这一分析不仅为现有的放行算法提供了依据，也为进一步改进撬棍操作奠定了坚实的基础。最后，提出了一种既能防止过流/过压，又能将对电网的不利影响降到最低的撬棍操作算法。通过详细的仿真对分析结果进行了验证和比较。
Crowbar is a popular device used to facilitate the fault ride-through of doubly fed induction generator (DFIG), which protects the power converter from the damage of overcurrent/overvoltage. The crowbar is activated once an overcurrent/overvoltage is detected, and it is desirable to release the crowbar as soon as possible in order to output active/reactive powers to the grid. But releasing the crowbar at an inappropriate timing may result in the recurrence of overcurrent. So, it is important to release the crowbar at an adequate timing. To this end, we analytically investigate the behavior of rotor current, and reveal that the current amplitude fluctuates periodically with a decaying magnitude. Hence, there is a set of release timings which may prevent overcurrent/overvoltage. Further, it is shown that these release timings are robust to the variations of voltage dip depth, generator parameters as well as wind speed. This analysis not only provides a justification for existing release algorithms, but also forms a solid basis for further improvement of crowbar operation. Finally, an algorithm is proposed for the crowbar operation which can prevent overcurrent/overvoltage while minimizing the adverse impact on the grid. The analysis is validated and compared via detailed simulations.