基于递归通用信号延迟叠加算子的单相锁相环

当电网电压存在谐波与直流偏移时，传统锁相环无法精确锁相。为此，提出一种基于递归通用信号延迟叠加算子的改进单相锁相环算法。该方法在锁相环前级引入递归通用信号延迟叠加算子，以产生正交信号并滤除谐波。接着在两相静止坐标系下，构建延迟采样周期滤波器，通过将正交分量延迟两个采样周期的方法抑制直流偏移。所提单相锁相环技术能够消除直流偏移和谐波干扰的影响，快速准确地获取基波和所需的特定次谐波信息，同时具有良好的动态性能和稳定性。最后，仿真与实验结果证明了该方法的可行性。

Single-phase phase-locked loop based on recursive implementation of generalized delayed signal superposition

When there are harmonics and DC offset in a grid voltage, the traditional phase-locked loop (PLL) cannot accurately realize phase lock. Hence, an improved single-phase phase-locked loop algorithm based on recursive-form generalized delayed signal superposition (RGDSS) operators is proposed. To produce the orthogonal signals and filtering of the harmonic, RGDSS operators are introduced into the pre-stage of the PLL. Then in a two-phase stationary reference frame, a delayed sampling period filter is constructed to suppress the DC offset by delaying the orthogonal component by two sampling periods. The proposed PLL, which has good dynamic performance and stability, can effectively eliminate the influence of DC offset and harmonics, and obtain the fundamental and desired harmonic information quickly and accurately. Finally, the feasibility of the method is verified by simulation and experiment. This work is supported by the National Natural Science Foundation of China (No. 51577162).