The Research Of New Microprocessor Relay Protection Based On DSP

Microcomputer protection is a comprehensive subject integrating theory with practice.It not only includes complicated theoretical knowledge and mathematical calculation methods,but also relates to the knowledge of power system automation,circuit,computer technology,DSP and other fields,as well as a variety of hardware technologies.The experimental teaching of power system microprocessor-based protection is an indispensable part of higher education.It plays an important role in training talents and improving overall quality.With the development of computer digital and information technology,new principles and schemes have emerged in microcomputer protection.This not only puts forward very high requirements for the hardware of microprocessor-based protection,but also increases the difficulty of learning and mastering.At present,there are still some problems in Microcomputer Protection Teaching in most universities in China.Previous microprocessor-based protection experiments mainly test the characteristics of relays,so that students can not understand the specific functions of relays in the relay protection system.The content of experiment in teaching is outdated,and the content of experiment that can be done is very few.Even if some universities can do microprocessor protection experiment,there are many shortcomings.The experimental device is simple,large and expensive,and is not suitable for large-scale popularization in Colleges and universities.At present,there are many kinds of microprocessor-based protection experimental devices in the market,but their practicability is poor,which makes the theory of microprocessor-based relay protection disconnected from the experiment,ignores the authenticity of power system simulation,and lacks systematic verification of the principle of microprocessor-based protection test.In order to meet the requirements of current experimental teaching of microprocessor-based protection,the advantages and disadvantages of various experimental devices of microprocessor-based protection are studied and analyzed in this paper.An experimental teaching platform based on the combination of hardware device of DSP and upper computer of software is proposed.The design objectives and ideas of experimental teaching system of microprocessor-based protection are introduced,and the experimental teaching is expounded.The structure and function characteristics of the learning system mainly include hardware design and software design of the host computer.Its characteristics lie in the "universality" of the device.The data acquisition subsystem of the device uses 32-bit MCF5275 of Motorola's high-performance ColdFire V2.0 core as microprocessor,with appropriate peripheral circuits to complete data acquisition and pre-processing functions;the software program is designed in structured C language,and the experimental data and results are displayed and processed.The whole experimental device of microprocessor-based protection has the advantages of convenient operation,perfect function and friendly user interface.It can not only carry out the characteristic experiment of individual relay,but also complete the comprehensive experiment of line protection systematically.It can form dozens of protection experimental items,which basically covers all levels of line protection of 110 KV and below.The content of teaching practice is rich,which fully meets the requirements of experimental teaching and training in our college.