Research On Hardward Test For Microprocessor-Based Protection Device

With the development of substation integrated automation for electric railway, reliability and maintainability have become the important requirements of microprocessor-based protection device. Test is one of the most important steps in the procedure of design and production of this kind of device. Test methods change and improve continuously. Automatic test is becoming main developing direction in electronics products test. So automatic test is developed and researched in SWJTU Xuji Corporation, which is used for testing the series of TA21 microprocessor-based protection device.Based on the analysis of the hardware configuration and characteristic of the microprocessor-based protection device, the research on functional self-test used for hardware test is taken, and the disadvantages are discussed. Then the paper gives a new test project for next generation protection device.The paper introduces the composing of functional modules and the test method. The functional modules cover with all application functions of the microprocessor-based protection device. The self-test software and the display interface software are programmed by LabWindows/CVI and assemble language. Program and messages are sent through serial port by the simulation debug tool, which finally displays the self-test result. By this means, the hardware of the protection device are tested before they leave the factory. The experimental result indicates that this method is fast, easy to use and invest, and applicable for practical use. In the end, the boundary scan test technology is introduced as the useful complement to functional self-test method, which can improve the fault isolation rate.