Fault Diagnosis And Risk Assessment Of Large Power Transformer

With the development of our country economy,people's production and living standards improve and power consumption increase rapidly.Then,the corresponding grid scale expands unceasingly and the number of power equipment has greatly increased.Transformer is one of the most important power equipment in power system.The power system failure which is because of transformer failure,not only causes significant economic losses,but also causes serious influence in people's daily life and production.Therefore doing fault diagnosis and risk assessment of the large power transformer is of great importance.The current research status of large power transformer fault diagnosis and risk assessment is introduced after reading and analyzing the paper at home and abroad.Put forward transformer state fault analysis method which is based on Failure Mode and Effects Analysis.The transformer is divided into nine section according to the structure and then analyze the state failure by layering classification.Establish the oil chamber's FMEA analysis form.The large power transformer fault tree model based on the theory of fault tree analysis is established.The events are divided into the top?intermediate and bottom events and the expert evaluation model is used to determine the probability of each event.Analyze the effect of different events on the transformer faults,and then establish overall failure probability calculation model of transformer and verify the feasibility of this method by analyzing the field transformer.Finally do the risk assessment of large power transformer.Put forward the failure probability and failure loss value in order to establish the risk value indicators.The failure probability is calculated by the fault tree model and the failure risk value is calculated by weighted sum of four fault element damage and the failure risk value is equal to the product of the failure probability and the failure risk value.Do risk assessment through the collection,statistics of a regional power transformer operation data.The evaluation result has a certain guidance on the maintenance strategy formulation.