Anti-interference Technology for Microprocessor-based Protection

High-speed processors widely used in microprocessorbased protection device improve the electromagnetic sensitivity of the hardware, and with the development of power system,the capacity of power system is becoming larger and the voltage level is becoming higher,which makes the environment of the microprocessor-based protection device much worse.In order to improve the anti-interference ability of the microprocessor-based protection device,a complete set of measures are put forward.First,the main interference sources of microprocessor-based protection and the influences on the operation of protective equipment are analyzed.Then,the EMC tests for microprocessor-based protection are summarized.The anti-interference measures are analyzed from the angles of hardware and software.In respect of hardware,the anti-interference measures for the main modules of microprocessor-based protection,including the power module,in-out module,analogy input module,communication module are put forward.In addition,the designing of digital-circuit-board and the structure of the microprocessor-based protection device is analyzed and certain measures to improve the anti-interference ability are given.According to the measures,a certain microprocessor-based protection passed the Ⅳ level EMC test,it proves the measures to be correct and useful.The paper provides some references to the microprocessor protection designers.