【摘要】 针对电网故障条件下,传统SRF-PLL在进行电网信号同步时存在频率和相位信号检测误差较大的问题,提出了一种基于级联滤波锁相环的电网信号同步方法.在QT1-PLL中,利用级联滤波结构改善系统的滤波性能,并使系统的响应速度得到提升.在锁相环路内增加相位和幅值补偿环节以消除电网频率偏移对锁相结果的影响.仿真和实验结果表明:在电压信号发生20°的相位跳变和4 Hz的频率跳变时,可以在1.5个电网周期内实现对频率和相位的准确检测;频率和相位超调量分别为0.5 Hz和4°时,满足并网系统快速准确的要求,验证了所提理论的正确性和有效性.更多还原

【Abstract】 In the case of grid fault conditions,the traditional SRF-PLL has large frequency and phase signal detection errors when performing grid signal synchronization,and a grid signal synchronization method based on cascaded filter phase-locked loop was proposed. In QT1-PLL,the cascaded filtering structure was used to improve the filtering performance and the response speed of the system. The effect of grid frequency offset on phase-locked results can be eliminated by adding phase and amplitude compensation links in the phase-locked loop. Simulation and experimental results showed that accurate frequency and phase detection can be achieved in 1.5 grid periods when the voltage signal has a 20° phase step and 4 Hz frequency step. When the frequency and phase overshoot are 0.5 Hz and 4°,respectively,it can meet the fast and accurate requirements of the grid-connected system,and verify the correctness and effectiveness of the proposed theory.更多还原