电压暂降波形数据分析法及其在监测系统中的应用

Voltage Sag Waveform Data Analysis Method and Its Application in Monitoring System

针对目前电能质量监测系统仅能监测和记录电压暂降统计特征从而造成大量暂降信息缺失的问题,该文以提高监测系统暂降波形分析能力为目的,提出一种基于自动分段和附加特征刻画的电压暂降波形分析方法并应用于监测系统。首先,针对目前尚无有效自动分段方法的问题,对三相基波电压幅值采取中值滤波并基于奇异值分解和自适应阈值检测暂降过渡段边界,从而实现暂降波形的自动分段。其次,在自动分段的基础上计算相位跳变、波形点、不平衡度和暂降类型等附加特征。最后,从暂降数据分析和高级应用的角度出发,考虑算法效率和工程可实施性,将所提研究方法开发为暂降波形分析软件并应用于实际运行的电能质量监测系统。通过仿真和实测波形数据对所提方法进行验证,结果证明该文方法能有效对暂降波形自动分段,且能准确计算更多的附加特征;基于该方法开发的暂降波形分析软件能够满足实际工程需要,可为后续数据分析与暂降高级应用奠定基础。

Current voltage sag characterization method takes magnitude and duration as two basic acknowledged characteristics,leading to significant information loss.Therefore,to enhance waveform analysis,this paper proposed a voltage sag waveform analysis method,which was developed into a software.Firstly,based on singular value decomposition method,automatic segmentation was proposed with adaptive threshold applied.Secondly,according to segmentation results,additional characteristics,e.g.phase angle jump,point on wave,unbalance and sag type,were calculated.Finally,considering efficiency and applicability,the proposed method was developed into a voltage sag waveform analysis software and integrated into operational power quality monitoring system.Simulated and measured data were utilized to validate the proposed method.Results show that the proposed method has higher accuracy in segmentation and more characteristics can be obtained.Besides,the waveform analysis software can meet practical needs and lay foundation for further analysis.