Chaos theory apply in high voltage transmission line defect detecting

To solve the problem of echo signal which is very weak, the Duffing equation and the method of detecting weak signal with chaos theory were studied. The signal would be annihilated by strong electromagnetic noises when detecting defects in high voltage transmission lines using electro-magnetic acoustic transducer (EMAT). A chaotic detecting system of weak signal was designed which combining with the technology of filter and the technology of autocorrelation. Simulink was used to simulate the new detecting system. The experimental result showed that the system could detect the useful ultrasound signal under the background of strong electromagnetic noises more effectively. It would improve the detecting signal-noise ratio (SNR) of system further.