Compared with the transmission transformer condition assessment, less data is one of the major problems that limit distribution transformer condition assessment work. This paper intends to solve this problem through reducing state variables dimensionality. First, through analyzing the principle of every state variables of distribution transformer by use of the maximum Eigen-value approach, the core state collection of assessing the distribution transformer is formed and the state variables dimensionality is reducing. Then, the initial results of distribution transformer condition assessment are obtained by using core state variables. Thirdly, the sensitivity of the non-core state variables to the evaluation results is calculated. Finally, the initial assessment result is modified considering the non-core state variables change and the sensitivity to get the final result. Through the above proposed method, the evaluation process need only consider the core state variables and the change of non-core state variables. This method not only reduces the demand for data, but also ensures accuracy of the results using the sensitivity correction. The results of a condition assessment instance of distribution transformer verify the validity of the method.
A Study of Condition Assessment Method of Gas-insulated Switchgear (Part II)
