基于自适应记忆长度最小二乘参数估计的实时相位跟踪方法

A Real-Time Phase Tracking Method Based on Least Square Parameter Estimation With Adaptive Memory Length

针对电力系统实时相位跟踪问题,提出了基于自适应记忆长度的最小二乘参数估计方法。该方法直接观测三相电网电压矢量角度,并将电压相位角分解分成基波相角和由谐波或不平衡引起的相角偏离两部分,并以电网基波初相位角和角频率为参数来建立观测方程。以整周期相位误差平方和最小为目标函数,采用自适应记忆长度递推最小二乘法进行实时参数估计。试验结果表明,在各种电网畸变情况下,该方法都表现出良好的实时相位跟踪特性。

In allusion to realtime tracking of system frequency and phase, a least square parameter estimation method based on adaptive memory length is proposed. This method directly observe the angle of voltage vector in three-phase power network, and the phase angle of voltage is decomposed into phase angle of fundamental component and phase angle deviation due to harmonics or system unbalance, and taking initial phase angle and angular frequency of fundamental component as parameters a observation equation is established. Taking quadratic sum of phase error in a full period as objective function, the realtime parameters are estimated by recursive least square method based on adaptive memory length. There is no trigonometric calculation in iterative process of the algorithm. The results of experiments show that the algorithm is of good tracking performance under kinds of distorted utility conditions.