Research On Line Protection Device Based On DSP

Distribution power line is responsible for electricity distribution which is an integralpart of power system. The safe operation of power line has a decisive role in the powersystem stable operation and the guarantee for the power reliability of users, so it is veryimportant to protect the distribution power line effectively and reasonable. With the rapiddevelopment of the power system automation technology and the digital integratedsubstation, the microcomputer line protection devices are adopted in the distribution lineprotection.In this thesis, the development of relay protection technology and line microcomputerprotection device is reviewed. DSP owns very strong digital signal processing capacity,fast speed of operations and high efficiency of code execution. Based on DSP technology,a line microcomputer protection device is designed according to the characteristics of10kV line, the existed problems in the current distribution line protection devices and thelatest requirements of distribution lines protection. The device integrates protection,measurement, control, detection and communication functions in one body which ownsperfect functions and strong reliability and stability. At the same time, it is easy andconvenient to do maintenance, debugging and extensions.The design of the device includes hardware part and software part. As for thehardware, the Texas instruments’32-bit fixed point DSP TMS320F2812is used as themain control chip. The main hardware circuit includes data acquisition module, digitalinput and output module, display module, communication module, clock chip, datamemory expansion, key circuit and so on. As for the software, the key program of thesoftware is designed first, and then the designs of interrupt sampling, current protectionprogram as well as the initialization program are given. The2FFT algorithm is used in thesignal processing as the protection algorithm. In order to improve the anti-interferenceability and ensure the stability and reliability of the device, the corresponding measures of the design which includes both hardware and software are taken.