基于双同步旋转坐标的单/三相通用锁相算法设计

提出了一种新型单相/三相通用锁相环算法。该算法将单相电压、三相电压统一视为三相不平衡信号,在双dq同步旋转坐标系上进行投影,利用二倍频分量提取网络来实现正序信号、负序信号的快速解耦,有效提高了锁相环低通滤波器的截止频率;同时,利用正序直流d/q比值作为锁相环反馈量,克服了交流母线电压幅值变化的影响;同时还介绍了算法的结构和原理,建立了锁相环传递函数。考察了锁相环传递函数的零极点分布,分析了采样周期、低通滤波器截止频率对锁相性能的影响。最后,进行了仿真和实验,证明了该算法的有效性。

Design of Single-phase/Three-phase Phase-locked Loop Algorithm Based on Double Synchronous Reference Frame

An improved single-phase/three-phase phase-locked loop algorithm is proposed in this paper. This new algorithm treats the single-phase circumstance as a special unbalanced three-phase situation and then a three-phase phase-locked loop technology can be utilized and improved. In order to fast eliminate the coupled influence caused by positive sequence signal and negative sequence signal, a double frequency components extraction network is analyzed and built up for the double dq-synchronous reference frame PLL close-loop algorithm. This paper introduces the structure of this new algorithm and builds its transfer functions. The position variation tendency of the pole-zero points caused by sampling time and low-pass filter's cut-off frequency is analyzed in detail and the analysis provide a direct guidance for PLL parameter design. In the end, simulation and experiment results verifiy the versatility, compatibility and effectiveness of this new phase-locked loop algorithm.