在线监测系统ITIC曲线暂降严重程度评估方法

ITIC Curve Sag Severity Assessment Method for Online Monitoring System

现行ITIC曲线标准中通过统计低压敏感设备受电侧电压暂降特征分布来评估电压暂降造成的影响,但直接使用电能质量在线监测的中高压暂降数据可能造成较大的评估误差。针对上述问题文章提出了一种在线监测系统ITIC曲线暂降严重程度评估方法,用以在缺乏低压侧电压数据情况下提高电压暂降严重程度评估的准确性。首先根据变压器的序分量传递特性对电网侧与设备侧之间的暂降传递进行分析,其次结合DFT运算对录波数据进行处理求取设备侧的暂降数据,然后以ITIC曲线对低压设备进行暂降严重程度及设备暂降后状态评估,最后通过案例分析进一步验证了评估方法的有效性。

In the existing ITIC curve standard,the influence due to voltage sag is assessed by counting the voltage sag characteristic distribution on the receiving side of low voltage sensitive devices.However,direct use of medium and high voltage sag data for power quality on⁃line monitoring may result in large assessment errors.In view of above issue,a kind of on⁃line monitoring system ITIC curve sag severity assessment method is proposed to,in case of absence of low voltage side voltage data,improve the accuracy of voltage sag severity assessment.Firstly,according to the sequence component transfer characteristic of transformer,the transient transmission between the grid side and the device side is analyzed.Secondly,the recording data is processed in combination with DFT operation to get the transient sag data of the device side.Then,the severity of the transient sag and the state of the device after the transient sag are assessed by suing the ITIC curve.Finally,the effectiveness of the method is verified by the measured data.