考虑线路电感时光伏逆变器输出相位的同步方法

通过分析线路电感对接入点电压波形的影响,指出采样电压的多个过零点区域关于实际电网电压的过零点具有严格的左右对称特征,从而提出一种改进的电压过零点相位检测方法。进一步针对线路电感和开关电压纹波较大的工况,给出了基于锁相环技术和傅里叶分析的相位检测新方法。仿真分析和实验结果验证了这2种相位检测方法的有效性。

Output Phase Synchronization Methodology for Photovoltaic Inverters Considering Influence of Line Inductances

Analysis is carried out regarding the side effects caused by the line inductance.The study indicates that the concrete zero-crossing band of the sampled voltage renders uniquely symmetrical manner about the zero-crossing point of the actual grid voltage.An improved voltage phase detecting method is presented based on zero-crossing calculations.Furthermore,specifically for large line inductance and voltage fluctuation,phase locked loop(PLL) technique and Fourier analysis are integrated to develop a new voltage phase tracking method.Both simulations and experiments well verify the effectiveness and accuracy of the proposed two phase detecting methods.