电能质量监测评估系统的研究

Study on Power Quality Monitoring and Evaluating System

为了准确、快速监测、分析和改善电力系统电能质量,基于虚拟仪器技术和面向对象编程方法开发了一套电能质量监测评估系统。该系统由数据监测子系统、通信子系统、数据评估子系统组成,采用快速傅立叶变换(FFT)提取电压、电流波形中的基波和各次谐波分量的幅值和相位信息,进而得到频率、基波有效值、谐波、三相不平衡、电压波动与闪变5项电能质量指标以及有功功率、无功功率、功率因数等参数。采用虚拟仪器技术来实现数据采集、数据上传、数据分析等功能,极大的降低了成本。现场应用的结果表明,系统具有实时性强、运行稳定等优点。

In order to monitor, analyze and improve power quality accurately and quickly, this paper presents the composition and functions of a power quality （PQ） monitoring and evaluating system, which is developed using the virtual instrument （Ⅵ） and object oriented programming （OOP） techniques. The proposed PQ monitoring and evaluation system consists of a data acquisition subsystem, a communicating subsystem and a PQ evaluating subsystem. The system obtains magnitudes and phases of the fundamental and harmonic components of voltage and/or current waveforms by using FFT. Further, active powers, reactive powers, power factors of these components are also provided. Based on these quantities, five PQ indices, i.e. frequency deviation, magnitude deviation, unbalance, flicker and harmonics are available. It extremely reduces development cost by virtue of the use of Ⅵ technology to develop the above mentioned subsystems. On site application of the proposed PQ monitoring and evaluation system proved its real time processing capability and reliability.