Method for detecting interface defects and interface states of post insulator

Abstract

The invention provides a method for detecting interface defects and interface states of a post insulator. The method comprises the following steps of selecting a plurality of space points on a main interface of the post insulator; obtaining a reflection time domain waveform of terahertz of terahertz wave at each space point under the reflection mode; enabling each space point to sequentially forma main pulse, a first echo pulse and a second echo pulse at the main interface, a second interface and a first interface; comparing the reflection time domain waveform of the terahertz at each space point and the reflection time domain waveform of terahertz in a non-defect area, wherein when a third echo pulse occurs or the energy of the echo pulse is increased, the corresponding space point has the interface defect on the detection plane. The detection method has the advantages that on the basis of analysis on the time domain waveform of the terahertz under the reflection mode, the detectionaccuracy is high, the operability is strong, and the feasibility is reliable; the evaluation requirement on the interface state of the polyurethane cast-in-place type composite post insulator can be met.

Description

technical field [0001] The invention relates to the technical field, in particular to a method for detecting interface defects and interface states of post insulators. Background technique [0002] This section is intended to provide a background or context for implementations of the invention that are recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section. [0003] Polyurethane pouring composite post insulators, as a new type of composite post insulators, have been widely used in busbar posts and disconnector post insulators of many key domestic projects since their development. This typical composite post insulator is usually composed of three insulating dielectric materials, which are the outer layer of vulcanized silicone rubber sheath (including the shed part), the middle circle of cylindrical epoxy and the volume filled inside the cylinder. The largest proportion of polyurethane foam. In this insulation structure...

AI Technical Summary

Problems solved by technology

From the basic structure of the polyurethane perfusion composite post insulator, it can be seen that the most likely defect caused by the stacked layered structure of the three materials is the defect at the interface of different materials, and this defect is often manifested as non-fitting at the interface, missing material

The existence of this kind of defect will distort the electric field in the post insulator, which may cause partial discharge or even cause the breakdown of the post insulator in severe cases. Therefore, this defect will bring great hidden dangers to the safe and stable operation of the power system

For this kind of defect, due to its hidden location, the effect of conventional defect detection methods may be unsatisfactory in terms of accuracy, feasibility and ease of operation.

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