Research On Condition Assessment Method Of Power Transformer

The condition assessment of the transformer can fully reflect the deterioration of the insulation system.It is one of the important ways to master the insulation condition of power transformer.At the same time,effective and reliable condition assessment is a prerequisite for the maintenance of the transformer,which can be used to guide the development of effective and feasible maintenance plan to pre vent the occurrence of major accidents.Therefore,the condition assessment of transformer is of great significance to the safety,reliability,stability and economic operation of the transformer itself and the whole power system.In this paper,the condition assessment of the transformer is mainly from the angle of the probability estimation of the transformer failure,with more accurate estimation of the degree of deterioration of the insulation of the transformer.Based on the stress strength interference model,a fault tree model is established to evaluate the working state of the transformer.The fault evaluation system solves the problem of common cause failure of each component of the transformer by establishing the corresponding relationship between the transformer failure mode,the stress and the fault component.The transformer condition evaluation system established in this paper includes the failure probability estimation model of the fault types such as overheat fault,discharge fault,damp fault and aging fault.By using time series method,the content of dissolved gas in oil is predicted,and the estimation model of the failure probability of the current and future over a period of time is established based on the stress strength interference model.On the basis of the stress strength interference model,a model for estimating the failure probability of damp insulation und er random stress is established.