正交滤波相量算法的故障暂态响应及校正方法

Fault Transient Response and Correction of Orthogonal Filter-based Phasor Algorithm

正交滤波相量算法在故障暂态过程中的响应与故障前电气量及故障初相角有关,输出结果不确定。为更快得到准确的故障后相量,利用正交滤波器的等效变换提出1种校正方法,以故障起始时刻为起点,仅利用故障后的采样值,随着不断扩展的数据窗,迅速将正交滤波相量算法输出校正到故障稳态结果,通过理论分析和数字仿真验证了该校正算法的有效性。所提出的校正算法适用于电流、电压、阻抗等电气量的计算,不受频率偏移和故障前电气量影响,相比于滑窗相量算法和两点乘积等短窗算法,性能有较大提高,且计算量增加不大。

The transient response of orthogonal filter-based phasor algorithm during fault transient is uncertain,which is related to pre-fault electrical quantities and initial phase angle.In order to get accurate post-fault phasor more quickly,this paper proposes a correction method employing the equivalent transformation of the rthogonal filters.The correction method is enabled after detecting a fault immediately,using only the post-fault sampled values.With the expanding data-window,the output of the orthogonal filter-based phasor algorithm is corrected to the steady-state result quickly.The validity of the method is verified by theoretical analysis and digital simulations.The proposed algorithm is suitable for the electrical quantity calculations such as current,voltage,and impedance,and will not be affected by frequency offset and the pre-fault electrical quantities.Compared with sliding-window phasor algorithms and short-window algorithms such as the two-point multiplication algorithm,the performance of the correction method is significantly improved with little computation.