变压器热点温度和等值老化热特征参数的研究

笔者阐述了变压器负载导则IEC 60076-7:2005推荐的内部温升差分方程解法中热特征参数的含义,分析了各热特征参数对计算结果的影响。基于热特征参数均匀分布模型和正态分布模型,运用蒙特卡洛法分析了典型负荷和高负荷下的变压器热点温升最大值和绝缘等值老化时间。结果表明,在典型负荷下热特征参数对计算结果影响较小,采用推荐值能满足估算需求;但是在高负荷下的影响较大,如果需要得到较精确的结果,需进一步确定热特征参数。

Influences of Thermal Characteristic Parameters on Power Transformer's Hot-spot Temperature and Equivalent Aging

The thermal characteristic parameters of the internal temperature-rise difference equation method recommended in IEC 60076-7:2005 Loading Guide for Oil-Immersed Power Transformer are elaborated.The influence of each thermal characteristic parameter on calculation results is analyzed.By varying these parameters under various load conditions and by Monte-Carlo simulation with uniform distribution and normal distribution of these variables,the power transformer’s hot-pot temperature and equivalent aging time are calculated,and the influences of the parameters on calculation accuracy are obtained.The results indicate that the influences are small under normal load,and the accuracy of the calculation can meet the estimation need by using recommended values;but the influences are great under heavy load,and the thermal characteristic parameters have to be obtained accurately to improve the calculation accuracy.