Discussion On Power Transformer Condition Based Maintenance Method Based On Rough Sets And Cloud Theory

Power transformer, as one of the most important equipments in power system, its good and reliable operation can make sure of the security and stability of power system. It is very important to timely and effectively master the condition of the power transformer. But recent reach methods on condition based evaluation conclude many disadvantages, such as the subject factors, one sided on selecting evaluation index and inconvenient using. So this paper proposes the. method on condition based evaluation which is based on rough set theory and cloud theory for the power transformer aiming at being reasonable, scientific and accurate.First of all, the evaluation measure basing on power transformer condition is proposed in this paper. It expounds the leading position of the state variables in the condition based evaluation of power transformer, and innovating the state variables selection method which is based on analyzing that the unified state quantity is not suitable for complicated regional environmental in our country. And concluding the power transformer state grade accurately can lay the foundation of the power transformer condition based evaluation method.Second this paper expounds weight coefficient can reflect the important degree of the state variables. On the analysis of the weight coefficient concluding method, rough set theory is chose as the theory in this paper. And rough set theory is improved by connecting with the actual situation to ensure the weight coefficient objectively and accurately.Third this paper puts forward the creative concept of interval evaluation, expounds the evaluation interval is an important part of the power transformer condition based evaluation, and uses cloud theory as the theoretical method for determining the interval of evaluation. According to reasonable utilization of the basic cloud theory, the maximum membership degree cloud generator is used to conclude the interval evaluation basing on constructing the cloud model, which provides the scientific theoretical foundation on state variables discretization and score. It provides scientific theory basis to determine the state grade of power transformer.Finally this paper combines the rough set theory and cloud theory to have a better apply in the condition based evaluation, establishes the evaluation system of power transformer, and expounds the specific function of each module. And it also writes the software program based on the theory to implement each step of the evaluation. At the same time, it used the actual case to prove the method’s correctness. It illustrates the method’s rationality, scientific and accuracy.