环境温度和环境热阻对单芯电缆导体温度计算灵敏度的影响分析

为了定量掌握运行环境对电缆导体温度的影响程度,以IEC60287电缆稳态温升公式为基础,推导出环境温度和环境热阻对导体温度影响的局部灵敏度公式。采用局部灵敏度分析法对影响电缆导体温度的2个环境因素进行分析,并进行了电缆温升试验。理论分析与试验结果表明,稳态运行下的电缆,导体温度直接受环境温度影响,环境温度越大则影响越明显,基本呈线性递增;环境热阻对导体温度的影响比较稳定,随着加载电流增大至另一个稳态,灵敏度系数只有小幅升高。

Analysis on Calculation Sensitivity of Single Core Cable Conductor Temperature Impacted by Environmental Temperature and Thermal Resistance

For quantitatively mastering situation of impact degree of cable conductor temperature affected by operational en- vironment, this paper deduces a local sensitive formula for conductor temperature affected by environmental temperature and thermal resistance based on IEC 60287 steady state temperature rise formula. It analyzes two environmental factors which may influence cable conductor temperature by taking method of local sensitive analysis and carries out tests of cable temperature rise. Theoretical analysis and test results indicate that cable conductor temperature is directly affected by envi- ronmental temperature under the condition of steady state operation, while the environmental temperature is higher, the im- pact is more obvious which presents linear increasing trend. Meanwhile, the impact on conductor temperature by environ- mental thermal resistance is comparatively steady, while loading current increases to another steady state, the sensitive fac- tor only rises by small amplitude.