基于双派克变换的新型三相锁相环技术

针对电网电压不平衡故障时,三相锁相环输出存在二倍频谐波扰动问题,提出了一种基于双派克变换的新型锁相环.对电压信号分别进行正序派克变换和负序派克变换,并将负序派克变换中的直流量乘以变换矩阵,通过交叉解耦可消除正序派克变换中的二倍频分量,有效提取了基波正序直流分量,可实现电网电压不平衡条件下的相位和频率准确跟踪.在Matlab/Simulink环境中建立了仿真模型,分析了锁相环在电网不平衡下的稳态响应.结果表明,本文提出的锁相环较传统的锁相环而言,在电网故障下更能精确检测电压相位和频率信息.

Novel three phase locked loop technique based on double Park transformation

Aiming at the problem that the double frequency harmonic perturbation exists in the output of three phase locked loop(PLL)when the power grid voltage has unbalanced fault, a novel PLL based on the double Park transformation was proposed. The positive and negative sequence Park transformation for the voltage signal was carried out, respectively. In addition, the DC component in the negative sequence Park transformation was multiplied by the transformation matrix, and the double frequency component in the positive sequence Park transformation could be eliminated through the cross decoupling. The fundamental positive DC component was effectively extracted, and the accurate tracking of phase and frequency could be realized under the unbalanced grid voltage condition. A simulation model was established in the Matlab/Simulink environment, and the steady state response of PLL under the unbalanced grid voltage was analyzed. The results show that compared with the traditional PLL, the proposed PLL can detect the voltage phase and frequency information more accurately under the grid fault.