Study On New Principle Of Components Protection--Transformer Protection Based On Wavelet Anlysis

Now, the large and huge generators and transformers are becoming the main units in power system The excellent protective system will guarantee the stability and security of power system better Two points grounding protection for rotor is one puzzle of generator protections The developments of computer and integrated circuit techniques provide better condition for applying novel protective theories The switching rotor's grounding protection which is on the basis of computer spreads rapidly because of its simplicity and sensibility0 This paper will discuss its extention's feasibility which is two points grounding protection for rotor0 After calculating detailedly, the paper analyses the theory's operating performance and puts forward an improving scheme As a new time-frequency analysis, wavelet transform is a research focus in the field of relaying protection0 People want to use wavelets? time-frequency localization to enhance the sensibility ~. selection and operating speed of protection0 This dissertation does some work in this area: firstly, the paper introduces the theories of multi-frequency channel analysis and singularity detection properties of wavelet transform 0 Secondly, some wavelets?properties of frequency are studied, these wavelets are always used in engineering0 Finally, based on the above, the paper proposed two new methods to identify inrush with WTO One is on the basis of dividing the frequency band with orthogonal WT, the other is using cardinal B-splines?derivative wavelet to detect singularity The results of analyzing a number of data generated by EMTP show that WT has its advantage on capturing signal's singularity and it has good prospect in relaying protection...