中文摘要：

分析了孤岛检测对于电网安全的重要性,提出一种间歇性无功扰动孤岛检测方法,应用在三相并网逆变器中。消除了传统的持续无功扰动孤岛检测方法存在孤岛检测盲区的缺点,通过间歇性无功扰动使公共耦合点（PCC）电压频率超出预设阀值,通过高/低频率检测判断孤岛发生。采用Matlab软件进行仿真研究并在基于TMS320x2812 DSP数字控制的并网系统平台上进行验证。实验结果表明：该方法算法简单,易于实现,不影响并网电流波形质量,具有检测速度快,无检测盲区（NDZ）等优点。

英文摘要：

The importance of islanding detection for grid safety are discussed, the intermittent reactive power distur- bance method is proposed and the proposed method is applied to three-phase grid-connected inverter.Considering the shortcomings of traditional persistent disturbance islanding detection method, the proposed method leads to the instab- ility of the voltage frequency at the point of common coupling （PCC）, the frequency is exceeded the allowable thresh- old and the islanding can be easily detected by using the under-frequency or over-frequency detection.Using Matlab/ Simulink software to simulation the method and DSP TMS320x2812 digital control platform to verify the grid-connect- ed experiments.Experimental results show that：the method is easily to carry to effect,have no non-detected zone（NDZ） and little influence on the quality of grid-connected waveform, the detected speed is fast.