光伏并网系统低电压穿越时电网电压跌落检测方法的研究

Research on Grid Voltage Drop Detection of Photovoltaic Grid-Connected System during LVRT

对目前检测电网电压跌落故障的方法进行了归类总结,从中找出适用三相光伏并网系统的检测方法,并对这些方法的检测原理进行了阐述,给出了各种检测法对电网电压跌落的判断量。最后在Matlab/Simulink中建立了仿真模型,从能否检出电压跌落、检出时间及谐波敏感度三个方面进行了比较研究。结果表明,基于相移操作的正负序旋转坐标变换检测法检测电压跌落时间短,对谐波有很强的抑制作用,适合应用在光伏并网系统中。

This paper summarized the current methods for grid voltage droF detection, and found out the detection methods suited for three-phase PV grid-connected system and the detection principles of these methods were described and discussed. Finally, a simulation model was established in Matlab/Simulink by which these methods were compared from the success of detection, detection time and harmonics sensitivity. The results show that the detection method of rotating coordinate transformation of positive and negative sequence based on phase shift operation is suitable for PV system because its detection time is short and harmonic suppression effect is good.