基于并网电流幅值扰动的孤岛检测方法

Islanding Detection Method Based on Grid-Connected Current Amplitude Disturbances

孤岛检测是小型风光并网发电系统的关键问题之一。针对在小型风光并网发电系统中应用主动检测法存在谐波污染或功率损失的问题,提出了一种并网电流幅值扰动的孤岛检测算法。在最大功率点跟踪(MPPT)过程中,采用MPPT进行并网电流幅值设定值的扰动;在最大功率点(MPP)附近时,采用周期交替并网电流幅值设定值扰动,检测到可能出现孤岛时,将并网电流幅值设定值减半来确认是否出现了孤岛。仿真结果验证了该方法的有效性。

The islanding detection is one of the key problems of small grid-connected photovoltaic or wind system. Aimed at the harmonic pollution or power loss when the active islanding detection is applied in the small grid-connected system,an islanding detection method based on grid-connected current amplitude disturbing was proposed. The reference amplitude of grid-connected current is disturbed by the maximum power point track( MPPT) algorithm in the process of MPPT,and the reference amplitude of alternating grid-connected curent is disturbed when the work point is near the maximum power point( MPP). When the island is determined to be possible,the reference amplitude of grid-connected current is decreased to half to confirm whether there is the island. The simulation results verify its effectiveness.