非理想条件下的电网同步锁相技术

Phase-locked Synchronization Under Non-ideal Grid Condition

针对电网电压存在扰动时传统同步坐标系锁相环存在的不足,提出一种新型电网电压同步方法。文章首先详细分析了影响同步坐标系锁相环锁相精度的电网电压扰动因素,在此基础上提出一种新型多静止参考坐标系解耦软件锁相环,该方法能够在多静止坐标系内有效地将电网电压基波分量同扰动分量分离并锁相,因此其相位跟踪结果不受电网电压不平衡、畸变、直流偏置等因素影响,响应速度快,锁相准确。仿真和实验结果验证了所提出方法的正确性和可行性。

Considering that the accuracy of the conventional synchronous reference frame phase-locked loop （SRF-PLL） is sensitive to the disturbance of grid voltage, a novel grid voltage synchronization method is presented. First, the disturbance factors of grid voltage affecting the performance of SRF-PLL are discussed. Then, a software method based on decoupled multi-stationary reference frame PLL is proposed, which can effectively separate the fundamental components from the disturbance components of grid voltage within the multi-stationary reference frame and perform phase-locking further. In this way, the phase tracking results will not be affected by factors such as grid voltage unbalance, distorted voltage and DC offset, so the proposed method has a fast response speed and higher phase-locked accuracy. Simulation and experimental results verify the correctness and effectiveness of the proposed method.