基于双重判据的微电网快速孤岛检测技术

Detection of islanded microgrid based on double criterions

为了实现微电网并网/孤岛模式的无缝切换,孤岛检测过程中的快速性、可靠性及微扰动性是至关重要的。根据微电网等值阻抗在孤岛前后突变的特性,构建了分压器电路,并通过并联谐振单元参数的优化设置,利用谐振单元端口电压包络线斜率突变和端口电压幅值变化进行孤岛检测双重判定,将孤岛状态的判定用时缩短到0.007 0 s以内的同时,极大提高了孤岛前后检测特征量的变化幅度。通过MATLAB/Simulink仿真计算验证了该双重判据应用于微电网孤岛检测的有效性。

The rapid,reliable and slightly-perturbing detection of islanded microgrid is essential for its seamless transition between grid-connection mode and islanded mode.A voltage divider is constructed according to the sudden change of microgrid equivalent impedance during the connection / disconnection of microgrid with grid,based on which,a parallel resonance unit is designed.It is proposed to adopt double criterions in the detection of islanded microgrid：the sudden change of resonance unit terminal voltage and the sudden change of its envelope gradient,which reduces the detection time less than 0.007 0 s and enlarges the variation of characteristic variable.Simulation with MATLAB / Simulink verifies the effectiveness of the proposed double criterions.