matlab仿真有源滤波器，三相电源输入，树春进行了PWM调节，可以调试输出正确波形，有不错的仿真价值-Active filter, can output waveform correctly, three-phase power input and output using the PWM controller for adjustment, waveform is correct, is more accurate

采用声卡进行声音采样，通过自适应滤波器进行主动消噪。(Sound sampling is conducted by sound card, and active noise cancellation is performed by adaptive filter.)