电网电压不平衡时高阶锁相环特性仿真研究

Simulation and Research on Characteristics of High Order Phase-Locked Loop under Unbalanced Grid Voltages

为了更加快速精确地跟踪电网电压不平衡时的相位,提出一种基于高阶带通滤波器的锁相方法,在解耦双同步旋转坐标系(DDSRF)的基础上,在正序αβ分量之后加入高阶带通滤波器进行滤波。通过在MATLAB软件中建立仿真模型,对电压跌落、相位跳变、频率改变等电网电压不平衡情况进行仿真研究,比较二阶、三阶、四阶BPF-PLL以及DDSRF-PLL的锁相性能。仿真结果表明该方法能够更精确地跟踪电网相位,锁相性能在DDSRF-PLL的基础上有进一步的提升,适用于广泛的工程应用场景。

In order to track the phase of power under unbalanced grid voltage more quickly and accurately,a phase-locked method based on high order band-pass filter is proposed.On the basis of decoupling double synchronous rotating flame(DDSRF),a high order band-pass filter is added after the positive sequence αβ component to filter.The simulation model is established in MATLAB software to simulate the voltage imbalance of power grid,such as voltage drop,phase jump and frequency change,and compare the phase-locked performance of second-order,third-order and fourth-order BPF-PLL and DDSRF-PLL.The simulation results show that the method can track the power grid phase more accurately,and the phase-locking performance is further improved compared with DDSRF-PLL,which is suitable for a wide range of engineering application scenarios.