三相并网逆变器主动移相孤岛检测研究

Islanding Detection Based on Active Phase-shifted With Positive Feedback for Three-phase Grid-connected Inverter

提出了一种基于频率正反馈的主动移相(APSPF)孤岛检测方法,适用于三相并网逆变系统。该方法通过引入频率误差形成主动移相角,并对系统的有功电流和无功电流采用不同的d-q变换形式,使得系统的有功不受频率误差的影响,而无功受控于主动移相角。经分析表明,该方法易于实现,对系统的无功功率影响小,且不影响并网电流的波形控制能力。仿真和实验证明了所提孤岛检测方法的正确性和可行性。

An islanding detection method based on active phase-shifted with positive feedback （APSPF） is proposed, which is suitable for three-phase grid-connected inverters.By introducing the active phase shift angle（APSA） that is proportional to frequency error and using different d-q transformations for active current and reactive current respec- tively,the active power is unaffected by the APSPF while the reactive power is controlled by the APSPF.Analyses show that the proposed method is easy to implement and has little impact on the reactive power without deteriorating the waveforms of the grid-connected current.Finally, simulation and experimental results verify the correctness and fea- sibility of the proposed method.