基于虚拟仪器的平方检测法电压闪变测量实现

Implementation of voltage flicker measurement with square-detection method based on virtual instrument

电压闪变已成为电力系统的重要污染,为实现闪变测量,简化了IEC推荐的平方检测法电压闪变测量过程,提出并建立了一种计算量小的基于Blackman窗插值FFT的平方检测法电压闪变测量算法,通过对离散的电压均方根值进行加窗插值FFT分解,求得电压均方根值的离散频谱数列Uf(j),对Uf(j)进行视感度加权处理,得到电压均方根值数列对应的瞬时闪变量p,进一步统计排序求得短时间闪变值Pst和长时间闪变值Plt。仿真实验验证了算法的可行性和准确性,在此基础上研制了基于虚拟仪器的电压闪变测量仪,给出了仪器构成与主框图程序,检验与运行证明了仪器的准确性。

Voltage flicker has already become a major pollution in power system. To realize voltage flicker measure- ment and simplify the measurement process based on square detection method suggested by IEC, a square detection method based voltage flicker measurement algorithm with less computation task is presented, which is based on Blackman window and interpolated FFT. Through interpolated FFT decomposition of discrete voltage mean square root value, the discrete spectrum sequence Uf（j） of the voltage mean square root value is acquired. Instantaneous flicker parameter p of the voltage mean square root value sequence is obtained through performing the sense degree weighting calculation on Uf（j）. And with further statistical sorting, the short time flicker value Pstand long time flick- er value Pit are obtained. Simulation results show the feasibility and veracity of the algorithm. Furthermore, a voltage flicker meter was developed based on virtual instrument; the instrument structure and main program block diagram are given. Test and operation results verify the veracity of the instrument.