摘要
本文研究了用小波变换降低噪声对正弦波间小相角差测量的影响。实际的正弦模拟信号经Ａ／Ｄ板采样后，会混入宽频带的随机噪声即所谓采集噪声，同时还会有直流、谐波等噪声信号混入。利用小波变换处理采集到的正弦信号，可以有效地抑制这些噪声。而且选择适当的基小波，正弦信号经小波变换前后的峰值点位置保持不变。因而，通过计算小波处理后两正弦信号相应峰值点间的时间间隔，即可求得它们之间的相位差。仿真计算和实测结果均表明本文提出的方法是有效的。
This paper investigates the effect of wavelet transform on the phase angle measurement of two sine waves with equal frequency.When the real sine waves are digitized by A/D converters,they are polluted by a wide band random noise which is refered as sampling noise.Direct currents component and harmonic waves in signals also act as noise.These will result in large error in the phase angle measurement.By wavelet transform,selecting proper kernel function and scaling factor,the signal to noise ratio of original waveform with sampling noise can be improved and the peak points of the signal keep unshifted.On the basis of these,phase angle between two digitized sine waves are gained after they are processed by wavelet transform.The results of simulation and experiment are also provided in this paper.
出处
《电工电能新技术》
CSCD
1999年第2期5-9,22,共6页
Advanced Technology of Electrical Engineering and Energy
基金
"国家攀登计划B"项目
关键词
数字相位测量
小波变换
降噪
噪声
相位测量
digital phase measurement,wavelet transform,sampling noise,noise reduction
