中文摘要：

在并网逆变系统中,必须能够准确、快速地检测出电网电压正序分量的相位信息,以便实现单位功率因数并网,然而,传统锁相环技术存在电网电压发生不对称故障时,其检测精度受到负序电压分量的影响而导致检测不准。提出一种基于相序解耦谐振（sequence-decoupled resonant,SDR）控制器的锁相环检测技术,该方法利用SDR控制器将正序电压分量从不对称电压中分离出来并对其进行相位跟踪,从而实现锁相环功能。仿真与实验结果表明,该方法在电网电压不对称、频率变化及电网畸变情况下,能对电网基波正序电压相位进行良好的检测。

英文摘要：

In grid-connected inversion system,it is necessary to fast detect the phase information of positive-sequence component of grid voltage to implement the grid connection under unity power factor.However,there is the defect in traditional phase-locked loop（PLL） that when unsymmetrical fault occurs in power grid the detection accuracy of PLL is affected by negative-sequence component of grid voltage and it leads to inaccurate detection.A PLL detection technique based on sequence-decoupled resonant（SDR） controller,in which the SDR is used to separate positive-sequence component of grid voltage from unsymmetrical voltage to trace the phase of positive-sequence component,is proposed,thus the function of PLL is implemented.Both results of simulation and experiments show that under the conditions of unsymmetrical system voltage,varying system frequency and distortion of system voltage the proposed method can detect fundamental positive-sequence component of grid voltage quickly and effectively.