基于频率自适应改进型梳状滤波器的并网锁相环技术

摘要

将梳状滤波器应用于并网锁相环技术中.针对梳状滤波器锁相环(CF-PLL)动态响应慢的缺点,引入校正环节,得到改进型梳状滤波器锁相环(ICF-PLL).基于ICF-PLL的s域模型,提出了ICF-PLL调节器参数的整定方法.为提高ICF-PLL对电网频率变化的抗扰动能力,提出一种基于频率自适应改进型梳状滤波器的锁相环(FAICF-PLL)和其数字实现方案.仿真和实验结果表明,FAICF-PLL在电网电压发生频率脉动、相角变化、畸变谐波和不平衡跌落时均能准确地跟踪电网电压相位,具有良好的稳态和动态性能.%The comb filter is applied to the field of grid-connected phase-locked loop.The main drawback of traditional comb filter based phase-locked loop (CF-PLL) is the slow dynamic response.The improved comb filter based phase-locked loop (ICF-PLL) is proposed by introducing the correction element.The setting method of parameters for the ICF-PLL controller is proposed based on its s-domain model.In order to improve the disturbance resisting ability of the ICF-PLL when the frequency of the power grid changes,an improved comb filter based frequency adaptive phase-locked loop (FAICF-PLL) and its digital implementation scheme are presented.Simulation and experimental results show that FAICF-PLL has good steady state and dynamic performance for its accurate phase locking under frequency ripple,phase angle change,distorted harmonic and unbalanced voltage sag grid conditions.