Residual Life Assessment Of Power Transformer Based On Load Rate And Risk Assessment

Power transformer is the hub electrical equipment of the power system,so,ensuring the reliability of transformer operation is of great significance for the whole power system.In the fault diagnosis of transformer,the transformer residual life assessment is an integral part,through the transformer residual life assessment,the reliability of transformer operation can be concluded,and it can provide guidance to transformer in formulating maintenance strategies,contingency plans and the improvement of designing,etc..This thesis proposes a new method for power transformer residual life assessment based on risk assessment and load rate.First of all,the risk assessment is taken on transformer,and the transformer running reliability is calculated,the transformer residual life is evaluated on this basis.Considering the various components of the transformer and their failures,power transformer fault tree is established based on the use of fault tree analysis;The transformer fault tree is analyzed quantitatively by Improved Fuzzy analytic hierarchy process(IFAHP).The relationship between transformer faults is described quantitatively by calculating the weight of each failure causes of transformer.Then,the objectivity and accuracy of the risk assessment is satisfied;The existing algorithm of fault weight is improved by introducing the particle swarm algorithm when calculating the weights of the cause of the problem.So the weight of the failure cause is solved rapidly and accurately.The speed and accuracy of the calculation of transformer reliability are improved and the practicability of the method is improved greatly.Finally,the transformer residual life evaluation model based on the risk assessment is used in specific circumstances,and the calculation results show that the method is applicable in transformer life assessment.Secondly,the residual life comprehensive evaluation model of transformer is established based on the reliability of transformer and operation load rate.Firstly,the hot temperature of the transformer is calculated;Then,the influence of transformer operation load rate to its residual life is calculated quantitatively,by researching the relationship of load rate and hot temperature,and the relationship of hot temperature and the transformer residual life;Finally,the transformer residual life evaluation model based on the risk assessment and load rate is established on this basis.The rationality and validity of the transformer remaining life evaluation method is verified through the actual example.Finally,the transformer residual life assessment software is developed In MATLAB GUI based on the transformer residual life assessment method proposed in this paper.The design of the software is reasonable,the planning of the software is clear and the function of the software is complete.This software is of high maneuverability and engineering application value.