Research on Parameters Sensitivities of Oil-immersed Power Transformers Calculation Method
Guo Zhihong1, Ma Qiang2, Chen Yufeng1, Wang Hui1, Chen Jingde3
1. Department of Shandong Electric Power Company Electric Power Research Institute, Ji’nan 250002; 2. Department of Power Dispatching and Control Center of Shandong Electric Power Company, Ji’nan 250000; 3. Department of Electrical Engineering Shanghai Jiao Tong University, Shanghai 200240
Abstract:The lack of calculation model parameters sensitivities and mathematic analysis in traditional research of transformer overloading, makes it inaccurate to get overloading capacity results as the way of choosing parameters. Therefore, overloading factors and parameters sensitivities have been studied to make it more scientific to calculate overloading capacity. Firstly, relationships between ambient temperature with initial rated load and overloading types have been studied. Analysis and calculation results reveal that overloading time of short-time emergency loading decreases in nonlinearity as ambient temperature increases; overload rate of long-time emergency loading decreases linearly. Also, with the augment of initial rated load, short-time emergency loading time decreases. Secondly, the sensitivities of parameters in calculation method are compared to find that the accuracy of top oil rise at rated load, oil index and cooling type has significant influence on the correction of calculation results. Finally, the results of numerical computation prove the correctness of conclusions.