The Software Research And Design Of Digital Portection System On DSP

Recently, microprocessor relay protection technology has been widely used in the electric power system and most collages have offered the professional courses of'Theory of power system protective relaying'and'Basis of multi-functional microcomputer protection'.However, as a compositive subject, the theory of microcomputer-based relay protection should be closely linked with practicality. Therefore, it is rather hard to meet the needs of teaching and research relying on the traditional experiment equipments for relay protection.To solve the problem, aiming at satisfying the needs of micro-computer relay protection teaching and experiment in colleges, this study develops a kind of system for microcomputer-based relay protection based on a detail survey on its research results and developments both at home and abroad. This system is a close loop which consists of micro-computer protection hardware platform, a PC and PW31 relay-protection measuring and protective device. The device and PC are linked by RS-232 interface; the man-machine interface is realized by Delphi7.0; MSCOMM functions are used to complete the communication between the up computer and device. This text puts forward the design thought that realize the multifunction digital protection experiment's function, further more, the typical and complex theory and arithmetic that is use in this system are lucubrated,so the protection software of pc is designed.The whole system is composed of number wave filter experiment module, protection measurement experiment module and protective component action characteristic experiment module. Specific details are as follows:1. Digital Filtering Training TestDigital filtering training test consists of the simple filtering, such as difference filtering, adding filtering, integral filtering and so on, and design filtering used zeros and poles. The display of the different digital filter's filtering effects enable students to understand the role of the digital filter and the main factors which impact the digital filter filtering effect. All kinds of filters are equipped with related words and formula that has brought great convenience for teaching and training. At the same time, considered other user's requirements, based on actual needs, users could import the actual parameters for the simulation testing or the development of new filters.2. Algorithm Training TestAlgorithm training test is divided into two parts:the ordinary algorithm testing and the functional algorithm test of the microprocessor-based relay protection. The ordinary algorithm testing includes two point product algorithm, derivative algorithm, half-cycle And integration algorithm. The functional algorithm test of the microprocessor-based relay protection includes Fourier series algorithm and solution differential coefficient equation algorithm.Comparison of different algorithms makes users understand the concept of algorithm, the advantages and disadvantages of the various algorithms. Users could program and operate the new algorithm, develop new algorithms.3. protective component action characteristic Testprotective component action characteristic Test is divided into two parts:Instantaneous overcurrent protection and distanceprotection. All protective component action characteristic Test are equipped with related words and formula that has brought great convenience for teaching and training. users could setting calculation for the simulation testing watching protective component action。Software of the system can be divided into PC software and hardware device software. Both of the two parts adopt to designed of modularization. The PC software can be mainly used for setting parameter of hardware control system, stimulant waveform data, measurement choice, protection styles choice and the integer value of protection. Furthermore, it also has the function to communicate with micro-computer protection experiment device.The system is very visual, universal and open. It could be applied not only to microprocessorObased relay protection teaching and training, but also to the experimentation on the exploitation of new relay protection principle.