油浸电力变压器过载能力核算模型参数敏感性研究

Research on Parameters Sensitivities of Oil-immersed Power Transformers Calculation Method

传统的变压器过载能力研究中,缺乏核算模型参数的敏感性及量化分析,使得参数的选取导致计算结果的不精确,因此,本文研究了过载能力影响因素及参数的敏感性,分析各个参数对过载能力的影响,为过载能力核算提供科学的参数选择依据。首先,研究环境温度、起始负荷率与各类过载关系,分析表明,环境温度的增加导致变压器短期急救负载过载时间的非线性减少,导致长期急救负载的过载倍数近似线性减少;起始负荷率的增加导致变压器短期急救负载过载时间的减少。其次,通过对比计算模型中各个参数的敏感程度,表明额定负载下顶层油温升、油指数、冷却方式参数值的可靠程度与核算模型计算结果的准确性息息相关。最后,结合算例对本文研究进行验证,数据结果充分证明了本文结论。

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.