稳态电能质量指标的检测及数字化实现

Steady State Power Quality Index Detection and Digital Realization

针对国家标准中量化的电压偏差、频率偏差、三相不平衡度、谐波、电压波动与闪变等稳态电能质量指标,探讨了检测电能质量的必要性,介绍了各指标的计算方法,设计并实现了电能质量在线监测系统,对电能质量的各项指标进行了监测。该系统基于虚拟仪器软件Lab VIEW编制检测程序,采用数据采集卡采集电网上的电信号,通过软硬件结合方法,实现快速、在线、准确测量各项电力参数,实时分析电能质量,实现各稳态电能质量指标的实时检测。模拟波形的试验检测结果显示,电压有效值误差小于0.5%,频率误差小于0.01 Hz,各次谐波电压误差小于5%,其结果误差满足国家标准,验证了该系统正确性和有效性。与传统的电能质量分析仪器相比,该系统具有所需硬件少、操作简单、开发周期短、扩展灵活、处理能力强等优点,其采集精度和速度、系统存储容量等方面均可满足现代电网研究的要求,具有一定的使用和推广价值。

According to the national standard,the quantitative steady-state power quality index mainly includes voltage deviation,frequency deviation,three-phase unbalance factor,harmonics,voltage fluctuation sand flicker.Firstly,the necessity of the detection of power quality are discussed.Afterwards,this paper introduces the calculation method of each index.The power quality online monitoring device was designed and implemented,as well as the realization of real-time detection of the steady state power quality index,which is based on virtual instrument Lab VIEW software of the detection program.With the help of data-acquiring card,combing the hardware and software,the system can detect power system data quickly,on line and accurately,and analyze electricity quality immediately.Through the simulation wave form of the test,voltage RMS error less than 0.5%,the frequency error is less than 0.01 Hz,every harmonic voltage error less than 5%.The result error meet national standards and verified the correctness and effectiveness of the system.Compared with the traditional power quality instrument,it meet there quirements of power system study for sampling speed,precision and capacity,it has the advantages of less hardware,easier operation,shorter development cycle,more convenient extension,stronger processing capacity and so on,it is worthwhile to be applied and popularized.