Separable high-voltage transmission line on-line electromagnetic non-destructive testing device

Abstract

The invention discloses a detachable on-line electromagnetic non-destructive testing device for high-voltage transmission lines, which includes an exciting direct current electromagnet that can be arranged radially along the transmission line for detecting defects on the steel core of the transmission line, and is used for detecting the butt joint of the steel core at the joint of the transmission line. The Hall sensor array at the position and the two-half eddy current coil array used to detect broken strands on the outer aluminum strand of the transmission line; make it easy to install on the transmission line and overcome obstacles. The DC electromagnet and Hall sensor array are completely separable from the transmission line, and the magnet core is placed along the radial direction of the transmission line, thereby shortening the distance between the two magnetic poles and reducing the loss of magnetic flux. Using two coils to energize to generate a direct current electromagnetic field is beneficial to realizing saturation magnetization of the transmission line and increasing detection sensitivity. In the two halves of the eddy current coil array, each group of coils adopts a double excitation form, which increases the penetration depth of the eddy current in the transmission line, which is beneficial to the detection of deep cracks and damage.

Description

technical field [0001] The invention relates to a non-destructive testing technology, in particular to a detachable on-line electromagnetic non-destructive testing device for a high-voltage transmission line. Background technique [0002] At present, the integrity of the high-voltage transmission line structure is very important for the safe operation of the transmission system. Since the transmission line works outdoors, it has been subjected to huge alternating tension and bending stress caused by vibration for a long time, which will inevitably cause cracks and broken strands in the conductors and ground wires of the transmission line. In addition, the surface of the transmission line will be damaged due to rapid changes in temperature and lightning strikes. If it is laid on the seashore or in an industrial area, it is easy to cause corrosion damage due to salt spray and acid rain. In addition, it is more likely to cause danger at the joint of the transmission line, beca...

AI Technical Summary

Problems solved by technology

In this patent application, the Hall sensor unit is arranged in the gap between the electromagnet core and the transmission line. Due to the limitation of the maximum detection range of the Hall sensor (usually 0.06 ~ 0.07T), the electromagnetic field in the magnetic circuit cannot be increased to The magnetic field strength of saturation magnetization, otherwise it will exceed the maximum detection range of the sensor and cause no change in the magnetic field strength to be detected

[0006] In this patent CN103645243A, the copper wires of the two separable eddy current coils are directly wound on the two halves of the plastic coil frame, so that there are only two independent coils in the circumferential direction of the transmission line, which cannot damage the aluminum stranded wire. Circumferential position for accurate judgment

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