基于 AFD 的微电网孤岛检测新方法

摘要

With the development and application of the micro-grid technology, the possibility of the unplanned islanding oper-ation is also increased.The status of the unplanned islanding operation may have a danger to the personal safety and the life of the equipment.In order to avoid the occurrence of adverse conditions, we should promptly responding to this phenomenon.Active Fre-quency Drift ( AFD) is the representative of active anti-islanding detection method.When the large power system is injected into the disturbance, the non-detection zone of the traditional active frequency drift method is determined by the total Harmonic Distor-tion ( THD) .In order to solve the shortcoming of the traditional AFD method, a new current perturbation injection method is pro-posed in this paper.The total harmonic distortion can be reduced by using this method, and non-detection zone is improved, the detection rate is increased.This paper builds a system modeling and makes a simulation for the proposed method by using Matlab/Simulink.Finally, the results of the experiment are analyzed in detail.%随着微电网技术的不断发展和广泛应用，计划外孤岛运行故障出现的可能性也就增加了。计划外孤岛运行状态可能对人身安全和设备寿命造成危害，只有及时应对才能避免不良状况的发生。传统的主动频率偏移法，当施加的扰动注入到大电网时，检测盲区由总谐波失真决定。针对传统方法的这一缺点，提出一种新的电流扰动注入方法。应用此方法可以减少系统的总谐波失真量，且检测盲区被改善，检测速度被提高。在Matlab／Simulink环境下建立了系统模型，对提出的新方法进行了仿真，并详尽地分析了试验结果。