强干扰下的SVG微弱谐波信号传感检测方法

Detection Method of SVG Weak Harmonic Signal under Strong Interference

静止无功发生器(Static Var Generator,SVG)微弱谐波信号处于强干扰区域的中心频带时,会影响谐波信号检测有效性。为提升谐波信号检测性能,提出强干扰下的SVG微弱谐波信号传感检测方法。在强干扰下提取出SVG信号,并采用修正投影阻塞法消除SVG信号中存在的干扰。选取振动传感器作为SVG微弱谐波信号检测仪器,由于振动传感器中的仪表放大器会对放大后的SVG信号叠加较多高频噪声,所以在强干扰抑制的基础上进一步滤除噪声。将振动传感器放置在振动台上,并检测处理后的SVG信号。通过数字示波器观测SVG微弱谐波信号在放大电路中的输出波形,判断信号在输送期间是否出现失真问题,从而实现SVG微弱谐波信号传感检测。实验结果表明,所提方法的信噪比高于23.51 dB,幅值检测误差低于0.63 Hz,频率检测误差低于7.1 Hz。

When the weak harmonic signal of static var generator(SVG)is in the central frequency band of strong interference area,the effectiveness of harmonic signal detection will be affected.In order to improve the detection performance of harmonic signal,a method of SVG weak harmonic signal sensing detection under strong interference is proposed.The SVG signal is extracted under strong interfer-ence,and the modified projection blocking method is used to eliminate the interference in the SVG signal.The vibration sensor is select-ed as the SVG weak harmonic signal detection instrument.Since the instrument amplifier in the vibration sensor will superimpose more high-frequency noise on the amplified SVG signal,the noise is further filtered on the basis of strong interference suppression.The vibra-tion sensor is placed on the vibration table and the processed SVG signal is detected.The digital oscilloscope is used to observe the out-put waveform of SVG weak harmonic signal in the amplification circuit and judge whether the signal is distorted during transmission,so as to realize the sensing detection of SVG weak harmonic signal.The experimental results show that the SNR of the proposed method is higher than 23.51 dB,the amplitude detection error is lower than 0.63 Hz,and the frequency detection error is lower than 7.1 Hz.