Study Of Interface Quality Detection And Evaluation Between Housing And Core Rod For Composite Insulators

The weak quality of housing-core interface of composite insulators is a significant reason for interface breakdown and core fracture. However, there is no uniform method for interfacial quality detection.Firstly, the principle of the compressive shear test of mechanics is referred and related test equipment is designed. A housing-core compressive shear test method which evaluates the interface adhesion is proposed in this paper. Through the analysis of the housing-core compressive shear test results of operating insulator samples, loading rate of the test is determined 10 mm/min and the separation work per unit area is determined as the criterion of interface adhesion. Samples were taken from composite insulators in operation for anatomy experiment and housing-core compressive shear test. The results show that the housing-core compressive shear test can effectively evaluate the interface adhesion.The separation work per unit area is taken as adhesion criterion and the interface adhesion of composite insulator in operation is tested and evaluated. The results showed that housing-core compressive shear test not only can be used to detect the interface adhesion of different positions of same insulator, can also be used to detect the interface adhesion of different insulators.The interfacial leakage currents of operating insulator samples and artificial aging insulator samples are detected. It is found that the leakage current value of boiled samples with housings over 1.00 mA is mainly due to too much interfacial defects. Water immerses interfacial defects in the boiling process, causing that the interface resistance decreases and the interfacial leakage current value increases significantly.The analysis results of housing-core interface quality of operating insulator samples and artificial aging insulator samples show that the interfacial leakage currents and separation work per unit area can respectively reflect the interfacial defects and interfacial adhesion strengths. The quality of housing-core interface consists of interfacial defects and interfacial adhesion strengths. Based on the analysis of interface quality, a quality evaluation method of housing-core interface is put forward by detecting the separation work per unit area and interfacial leakage currents.