Research On Ultrasonic Nondestructive Testing System For Composite Insulator Core Rod

Using synthetic resin and glass fiber,the composite insulator core rods is the main body of mechanical insulators and internal insulation in composite insulators.The quality of the composite rods influenced the security and stability of power transmission system directly,so it is of vital importance for the rods' non-destructive testing.This paper has mainly studied the ultrasonic non-destructive testing of composite insulator mandrel.In this paper,the measuring principle of hollow mandrel and solid mandrel is introduced,and analyzed the sound field characteristics of circular ultrasonic transducer and wave equation model and its general solution in cylindrical coordinate system.And on this basis,we designed the ultrasonic non-destructive testing system of composite insulator mandrel,explicated the hardware circuit design and FPGA design,and developed the master computer.Among them,the design of hardware circuit included ultrasonic pulse transmitting circuit,isolation limiting circuit and echo.The signal acquisition circuit,etc.And studied knowledge related to the signal integrity and electromagnetic compatibility,the 6-layer PCB design was implemented by rational placement and routing.After that,considering the characteristics of the hardware circuit,we finished he FPGA program design and the Verilog program of each sub-module,verified its key modules through simulation and completed software-hardware tests.Finally,we carried out series of tests on the core rod non-destructive and electromagnetic compatibility,the results demonstrated that artificial flaws of 0.6 mm in diameter can be detected in the hollow insulator and the solid insulator,but the system can still work in the highest level of interference specified by the national standard.This paper is jointly developed with the Engineering Electromagnetic Field and Applied Technology Department of the Institute of Electrical Engineering,Chinese Academy of Sciences.