DIPR-PLL在复杂电网故障下的性能分析

Performance Analysis of DIPR-PLL Under Complex Power Grid Faults

为了解决双二阶广义积分锁相环在电网故障工况下不能精准锁相的问题,以比例谐振控制器环节为基础,提出了一种基于改进式比例谐振控制器的正交发生器。在频域下分析可得,双二阶广义积分锁相环呈现低通特性,即对于高次谐波具有一定的抑制作用,但是难以滤除直流分量;而双改进式比例谐振锁相环呈现带通特性,对某一频率下的信号具有较大的增益作用,对高频谐波、直流分量能够有效抑制,因此改进式比例谐振锁相环能够在电网故障情况下准确提取基波正序相位信息,提高逆变环节的功率因数。通过实验表明,当电网电压跌落、相位突变、波形畸变和含直流分量时,相较于双二阶广义积分锁相环而言,双改进式比例谐振锁相环锁相精度更高,且对于非基波分量的抑制能力更强,有效增强了系统的鲁棒性。

This paper proposed a quadrature generator based on the theory of the improved proportional resonance controller.It could solve the problem that the dual second-order generalized integral phase-locked loop cannot be accurately phase-locked under grid fault conditions.The analysis in the frequency domain showed that the double second-order generalized integral phase-locked loop presented a low-pass characteristic,which meant it could suppress the effect on the higher harmonics.But it is hard to eliminate the DC component.He double improved proportional resonant phase-locked loop presented band-pass characteristic,which had a large gain effect on the signal at a specially appointed frequency,effectively suppressed the high-frequency harmonics and the DC component.Therefore,the improved proportional resonant phase-locked loop can collect accurate fundamental positive sequence phase information and promote the power factor of the invert-loop.The experimental result shows that in different situations,such as grid voltage sag,phase mutation,waveform distortion,and DC component,the dual improved proportional resonant phase-locked loop has higher phase-locking accuracy than the dual second-order generalized integral phase-locking loop.Moreover,the dual improved proportional resonant phase-locked loop has better suppression capability for non-basic components,and it could effectively enhance the robustness of the system.