摘要
研究变频调速方式下工况变化和供电电源的谐波成分对调速系统的振动信号、运行噪声、电流、电压等信号变化规律的影响,在Donoho D L和Johnstone I M提出的多分辨分析小波阈值去噪方法的基础上,讨论了sqt-wolog、rigrsure、heursure、minimaxi四种常见的阈值与新的阈值函数——能量元阈值确定方法在变频系统的信号去噪过程中的效果。通过MATLAB试验仿真,结果表明新的阈值法可以彻底滤除信号中的噪声和无用的高频分量,尽可能地减少低频和有用高频信息的损失,有效地提高变频调速系统非健康诊断的精确性。
The effect of operating mode and harmonic component of power supply to the vibration signal, running noise, current and voltage signals of the governing system is studied under frequency control. On the basis of multi resolution analysis wavelet threshold noise elimination method proposed by D. L. Donoho and I. M. Johnstone, common threshold val- ue and new threshold function of sqtwolog, figrsune, heuresure and minimaxi are discussed, that is, the effect of energy threshold method in the signal noise elimination of the frequency control. By MArl＇LAB test simulation, the results show that the new threshold method can completely eliminate the noise and useless high frequency component of the signals, reduce the losses of low frequency and useful high frequency information as low as possible and increase non-healthy di- agnosis accuracy of the frequency control system.
出处
《电气开关》
2010年第3期62-66,共5页
Electric Switchgear
关键词
变频调速
阈值函数
小波变换
健康诊断
frequency control
thereshold function
wavelet transform
healthy diagnosis
