基于DSP的电压暂降检测方法研究

Research of voltage sag detection methods based on DSP

电压暂降是一种严重的电能质量问题,基于DSP电能质量在线监测装置可以对电压暂降进行实时的检测分析。介绍了电压暂降幅值的检测方法,研究了有效值检测方法、瞬时电压dq分解法以及其改进后的αβ-dq变换检测法,并将其在DSP中进行验证,验证结果证明了这几种检测方法的有效性。这些方法均在检测上存在一定的延时,研究发现,不同的暂降深度对应的检测延迟时间有所不同,通过计算得出了电压暂降起始时刻的延时误差曲线,可以利用该曲线进行误差修正,进而得到更为准确的电压暂降起始时刻。仿真结果证明了该曲线能够修正误差时间。

Voltage sag is a serious power quality problem, the voltage sag can be detected and analyzed online using the power quality monitoring device based on DSP. The paper presents some methods to detect the characteristics of voltage sag, such as root-mean-square（RMS）, dq conversation of instantaneous voltage and its improved αβ-dq transform method, which are verified in the DSP and the results are correct. These ways all have the problem of time delay when detecting voltage sag, and different sag depths correspond to different detection delay time. According to the delay problems of voltage sags detection, the paper obtains the delay error curve of the starting time of voltage sags. In order to obtain more accurate starting time of voltage sags, these curves can be used to correct the error. The simulation results verify that the curves can correct the error time.