A Study On Fault Diagnosis And Location Of Partial Discharge Fault Of Oil-immersed Transformer

With the rapid economic development, the demand for electricity of all walks of life in our country is increasing day by day. The security and stability of the grid is essential to the national economy. Construction of'strong'smart grid goal has been proposed by our country. And as an important part of the Smart Grid, the intelligentized transformer substation is very important. The research of diagnosis and location technology of large oil-immersed transformers determines the success or failure of realization of the intelligentized transformer substation.Currently, the use of a wide range of fault diagnosis algorithm mainly relies on the content changes of the characteristic gas which is dissolved in the insulation oil. This kind of ratio diagnosis algorithm has high accuracy and good operability, but it also has the case of error or missing diagnosis. In this thesis, after full analyzing the development state and the problems of the current transformer fault diagnosis algorithm, the algorithm for fault diagnosis which is the combination of fuzzy diagnosis and rule-based reasoning proposed. The algorithm relies on three ratio diagnostic algorithms. In this algorithm, fuzzy theory is applied to three ratio method and rule-based reasoning is used to test and verify the results. The algorithm prevent the case of miscarriage of justice and the missing.In addition to studying this fault diagnosis algorithm, fault location of the transformer is also studied in this thesis. Currently, with the increase of transformer capacity, the transformer structure more complex, the cost of maintaining increasing, it is very important for the e personnel to locate the fault location accurately, it can reduce maintenance cycle time and cost greatly. In this thesis, the current main methods of fault location and the problems are analyzed firstly, and then introduced the ultrasonic and electrical fault lacaion principles and methods of fault location. In this thesis,the methods focuse on a common partial discharge transformer failure. They have high positioning precision and accuracy, and if they can be used with the computer technology,there will be great practical value.