考虑多维特征刻画的电压暂降严重程度评估方法

Voltage Sag Severity Assessment Method Considering Multi-dimension Characterization

随着高新技术的发展,越来越多的新型用电设备对暂降波形的不同特征敏感,因此迫切需要改进电压暂降严重程度评估方法。由于目前电压暂降特征刻画方法仅计算暂降幅值和持续时间2个基本特征,暂降严重程度评估结果无法有效反映设备受暂降的影响程度。为此,从电网侧暂降严重程度评估的角度出发,提出一种考虑多维特征刻画的电压暂降严重程度评估方法。针对现有暂降严重程度评估方法存在的诸多问题,提出电网侧电压暂降多维特征刻画方法和用户侧典型耐受曲线模式库。根据监测波形中提取的多维特征值与典型耐受曲线所对应敏感特征向量的相似性建立隶属度函数评估综合严重程度。最后,基于电网实测数据对文中方法的有效性进行验证,结果表明该方法能够有效反映不同暂降特征对敏感设备的不同影响程度,且相较于传统方法在少量敏感设备耐受曲线的前提下评估准确度更高,更适用于电网侧暂降严重程度评估。

With development of new advanced technology, many new types of equipment are sensitive to voltage sags. Since lots of characteristics are ignored in existing characterization methods, their voltage sag severity assessment is invalid for some new types of equipment. To improve this situation, this paper proposes a severity assessment method based on voltage sag multi-dimension characterization. To overcome the drawbacks in existing methods, the multi-dimension characterization method is proposed to obtain more information from recorded sag waveform. A pattern bank of sensitive characteristics is established with a set of typical tolerance curves. Then, similarity between multi-dimension characteristics and sensitive characteristic set is utilized to determine membership function of severity assessment. Finally, field measured waveforms are used for validation. Results show that the proposed method has higher accuracy than existing methods, especially when the information of customer side is limited.