Ultrasonic detection sensor and signal processing method thereof

Abstract

The invention discloses an ultrasonic detection sensor and a signal processing method thereof. The ultrasonic detection sensor comprises a sensor shell, and a piezoelectric unit and an auxiliary partwhich are arranged in the sensor shell; the piezoelectric unit comprises a receiving piezoelectric wafer and a transmitting piezoelectric wafer arranged below the receiving piezoelectric wafer; and the transmitting piezoelectric wafer and the receiving piezoelectric wafer are of an axial series structure. Noise reduction processing is carried out in a mode of combining CEEMDAN and a wavelet noisereduction algorithm. According to the invention, the transmitting piezoelectric wafer and the receiving piezoelectric wafer are arranged to be of an axial series structure, so that the ultrasonic transmitting power of the sensor is far greater than that of a conventional sensor; the piezoelectric unit is composed of a transmitting piezoelectric wafer and a receiving piezoelectric wafer, and the receiving sensitivity is far higher than that of a conventional sensor; according to the sensor signal processing method for ultrasonic detection, CEEMDAN and a wavelet noise reduction algorithm are combined, and the signal to noise ratio and the resolution of signals are further improved. In-situ detection of the conductive copper plate of the hydroelectric generating set can be completed.

Description

technical field [0001] The invention relates to a sensor for ultrasonic detection, in particular to a sensor for ultrasonic detection and a signal processing method thereof. Background technique [0002] With the extension of the operation time of domestic hydropower plants, especially the motor generators of large pumped storage units have material structure failures under alternating working conditions, especially the rotation instability of high water head and high speed units. Fatigue phenomena such as material fatigue, coil deformation, etc., seriously affect the safe operation of the unit, and some power plants even cause rotor "sweeping" accidents, and the equipment of the unit is damaged, causing huge social and economic losses. [0003] As a key component of the generator, the importance of the conductive copper plate is self-evident, and its integrity and reliability are the basis for the safe operation of the entire unit. For units above 500rpm, due to the speed ...

AI Technical Summary

Problems solved by technology

[0008] However, in the in-situ ultrasonic detection of the conductive copper plate of the hydroelectric generator set, due to the large attenuation rate of the ultrasonic copper plate material, the narrow detection surface and the coupling of the curved surface caused by the structure, the conventional ultrasonic detection sensor cannot complete the detection.

Specifically, the conventional sensor has insufficient ultrasonic transmission power and low receiving sensitivity, resulting in a very low signal-to-noise ratio and resolution of the finally obtained signal, and it is completely impossible to obtain the conductive copper plate through this content, so that the conductive copper plate cannot be completed. Ultrasonic testing of the original flavor

[0009] To sum up, the existing conventional ultrasonic detection sensors have the problem of being unable to complete the in-situ ultrasonic detection of the conductive copper plate of the hydroelectric generator set

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