Study Of General Hardware Platform For Relaying Protection Based On DSP

With the development of microprocessor based relaying, more attention have been focused on the new principles and schemes which improve the performance of relaying, especially the principle based on the fault wave feature or the high frequency component and the intelligent relaying scheme based on the neural network or fuzzy set. The applications of them are also implemented gradually, which require more demanding about the performance of microprocessor relay hardware. The rapid development of integrated circuit and computer technology provide the possibilities for building more versatile hardware platform of microprocessor relay. Therefore the developments of hardware platform of microprocessor relay with more reasonable structure and better performance are urgent affairs. With this understanding, a set of Digital Signal Processor based novel hardware platform of microprocessor relay is scheme out in this dissertation.After general studying of existing literature of both home and abroad, the problems of existing microprocessor protection device are analyzed in this dissertation. Furthermore, the hardware platform scheme of microprocessor relay consisting of Complex Programmable Logic Device and Digital Signal Processor is given in the dissertation. The applications of Complex Programmable Logic Device in the microprocessor protection device are expatiated on in the dissertation, and the design of a frequency hardware measuring circuit based on equal precision principle is introduced. In the aspect of data collection, the advantages and disadvantages of voltage-frequency converting A/D and sequential approximation A/D are compared, and a new high speed data collection system is brought forward. The communication system of device is studied. Making allowance of requirement of device itself and substation automation, both serial port and Ethernet interface are equipped to the device. The disadvantages of conventional binary inputs/outputs circuit are discussed and furthermore some innovative ideals of its amelioration are given, which take the advantage of specific binary inputs/outputs chips to make the design compacter and more reliable. At the end of the dissertation, a conclusion is given, and the existing problems are specified, and some possible measures to improve are also given. The adoption of Digital Signal Processor based protection device makes the capability and speed of computing of system much better, and lays a foundation for complicated software. At the same time, the use of Complex Programmable Logic Device makes the design of circuit simpler and enhances the flexibility and reliability of the device. The realization of the device provides a general hardware platform for microprocessor relaying.