Research On Condition Assessment Method For Power Transformer

The incoming competition of the electric power industry demands that the power transformer management must be more efficient.In that case,the traditional power transformer preventive maintenance strategy appears to be behindhand;the maintain strategy based on condition is becoming more and more popular.The condition assessment of the power transformer is the foundation of the maintain strategy based on condition,and the accurate assessment of the transformers is the key to define the maintaining time.Therefore the condition assessment of the power transformer is very important for the practice.The attributes in every aspects of the power transformer were studied and distinguished into three classes which were dielectric strength of the transformer body,the mechanical strength of the transformer body and the condition of the attachments.Then the attributes system were built,which matched better with the IAHP.The AHP(Analytic Hierarchy Process)is one of the most popular algorithms to compute the weights of attributes.This paper introduced the classical AHP,and pointed out that the judgment matrix of the AHP was difficult to satisfy the consistency needed.Considering that,the involving attributes weights were computed by IAHP,which built the initial matrix with "three scale" rule instead of "nine scale" rule.The IAHP makes the weights computing more easily and avoids the compromise of the expertise.As the invariable weights makes the excellent attributes "drown" the inferior attributes,the weights of the attributes must be modified in terms of the practical attribute values.If a practical attribute value is far from the normal value,the weight of the attribute would be strengthened.Then the inferior attributes can be highlighted and the assessment result became sensitive enough to those inferior attributes.For some of the attributes,larger is favorable;for the others,smaller is favorable.So the attributes were deteriorated to be more regular.Then the power transformer condition assessment strategy was built based on the grey cloud clustering theory with the final weights and the practical attribute values.Finally,an assessment result of a power transformer verified that the power transformer condition assessment strategy was efficient.