基于波形匹配的谐波责任划分方法
Waveform Matching Based Method for Harmonic Contribution Determination
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摘要: 为了对公共连接点的谐波责任进行量化,提出了一种基于波形匹配的谐波责任划分方法。首先建立谐波电压幅值与谐波电流幅值的线性回归方程模型,规避了对谐波相角的直接测量。考虑到背景谐波波动会对方程求解带来误差,利用动态时间弯曲距离对关注时间段的谐波数据进行滑动分析,筛选出谐波电压与电流相似度较高的子序列。运用最小二乘法对筛选出的子序列进行回归计算求得系统侧等效谐波阻抗,进而计算用户侧谐波电压责任。仿真分析与实际工程分析的结果说明了所述方法能够抑制背景谐波波动的影响,相比于已有方法具有较高的准确性。Abstract: In order to quantify the harmonic contributions on the point of common coupling(PCC),a new method based on waveform matching is proposed.Firstly,a model of linear regression equation between harmonic voltage amplitude and harmonic current amplitude is established,which avoids the direct measurement of harmonic phase.In consideration of the error to the equation brought by the fluctuation of the background harmonic,the dynamic time warping(DTW)distance is used to analyze the harmonic data to select the sub sequences of high similarity.The utility equivalent harmonic impedance is estimated by the least square method,and then the customer harmonic contributions are calculated.The results of simulation and field measurement analysis show that the method has high accuracy and can restrain the influence of the fluctuating harmonic in the background.