Study Of Algorithm And Man-Machine Interface For Relaying Protection Based On DSP

With the development of micro-electronics technology and computer technology, relay protection equipment based on micro-computer has been improved unceasingly from hardware and software. In the aspect of hardware, it has developed into 16 bit or 32 bit-digital signal processor and highly compositive embedded micro-processor from single chip. In comparison to the rapid development of hardware, the development of software has lagged. So it is urgent to construct new hardware flatform and adopt more advanced and perfect software algorithm and tapping measures based on it. Research of this paper can be divided into the following aspects. 1. The paper introduces a new type of protection hardware flatform based on 32 bit float DSP and analyses the character and performance of some parts: the core processor CPU, complex and programmable logic device CPLD, AD switching circuit, memory system and peripheral interface. 2. The paper analyses characters of various typical algorithms to pick up requisite electro-value of basic frequency or high frequency from fault current or voltage signals, simulates and contrasts all the algorithms with constructed fault waveform and real fault recording data, makes a study of the merits and shortcomings of all the algorithms, and then puts forward a new type of algorithm which combines recursive least squares algorithm and all-period Fourier algorithm with differential filter. 3. The paper makes a study of how to realize the algorithm on the DSP hardware flatform. It introduces the program flow chart, data store format, reading and writing method in detail, and also points out some questions that need to be paid attention to in the programming. In order to insure the precision of the algorithm, the hits in a period must be fixed, so the paper puts forward a method which can adjust sampling frequency in real time according to the real frequency of the power system. 4. The paper introduces the embedded Graphical User Interface technology into the design of the equipment's interface. It analyses the technical characters and system structure of embedded GUI, discusses the necessary and executable points to adopt this technology, then introduces the developing principle, approach and means in detail with the example of μc /GUI, and then points out some questions that need to be paid attention to in the developing process. In the end, the paper summarizes that it can improve the action speed, veracity and the monolithic performance of the equipment when adopting the new algorithm and embedded GUI technology on the DSP hardware flatform.