基于选择电极法的精密接地电阻测试仪的研制-控制理论与控制工程专业论文.docxVIP

Subject : Development of The Precise Grounding Resistance Measuring Tester Based on the Method of Selective electrode Specialty : Control Theory and Control Engineering Name : Zhang Xiutong （Signature） Instructor : Guo Xiucai （Signature） ABSTRACT Along with the development of electric power system and the expansion of the scale of power grid, all kinds of microcomputer monitoring equipment general application, the demand of the grounding device is more and more, and the resistance of the grounding device size is one of the major criteria for good grounding. Firstly this paper introduces the development and present situation of the grounding resistance measurement,then on the basis of analyzes of the traditional grounding measuring device and measurement methods, the virtue and principle which is based on the frequency conversion method and the method of selective electrode grounding resistance measurement are studied, moreover the design scheme of grounding resistance design which uses the combination of the frequency conversion method and the method of selective electrode are puts forward. Secondly, the paper studies on the resistance measurements algorithm deeply.By using fast Fourier transform (FFT) grounding resistance measurement, its hard to do synchronous sampling and integer period truncation, and it will also affect the accuracy of measurement by the fence effect and frequency spectrum leakage which FFT resulting into. Through FFT add window interpolation can effectively eliminate the effect and improve the accuracy of the calculation the frequency and amplitude of the voltage and current of grounding resistance. Based on the scheme design of the system and the research of the adding window in FFT interpolation algorithm, this paper realizes the high precision grounding resistance measurement system for ADSP-BF504F core processor. The measurement system includes hardware realization and software realization. The hardware of the system is mainly compose