作　　者： ; ; ; ; ; ; ;

机构地区： 华南理工大学电力学院

出　　处： 《高电压技术》 2009年第9期2138-2143,共6页

摘　　要： 导体温度是反映电缆运行状态的关键因素,因而有必要实现对它的监控。实际中对运行电缆导体温度的直接测量难以实现,工程中常采用计算的方式来获取,而复杂多变的电缆外部因素使得对导体温度的精确计算也非常困难。为此,在电缆外皮温度监测的基础上,建立了单芯电缆暂态热路的数学模型;分别推导出只考虑电流变化和只考虑表皮温度变化两种情况下的暂态温升递推公式,进而推导出单芯电缆暂态温度的完整叠加公式;并采用经典4阶Runge-Kutta法求解微分方程组计算电缆本体温度。同时编制了电缆暂态计算软件,可根据电缆外皮温度的监测,计算电缆导体和金属护套暂态温度。为验证暂态模型和软件编制的正确性,在试验现场进行了单芯电缆暂态温升试验,并将计算结果与试验测得的温度数据进行了对比验证。结果表明,基于电缆外皮温度监测的单芯电缆暂态温度计算具有较高的精度,可用于单芯电缆实际运行中的温度控制、电缆状态监测及其故障预警等方面。 The real time measurement or calculation of conductor temperature is necessary; whereas it is hard to measure for technical difficulties, calculation is another option. The conductor temperature is associated with the temperature and thermal resistivity of material surrounded （e. g. soil ）, which is diverse with season and its water content and make the calculation complicated and inaccurate. Consequently, based on its jacket temperature monito- ring, the transient thermal circuit model is established. Recurrence formulas of transient temperature rise of its con- ductor only considering current change and only considering jacket temperature change are both derived to obtain the integrated superposition formula of calculating transient temperature of single-core cables. The classical fourth-order Runge-Kutta method is used to solve differential equations of conductor temperature on the basis of the temperature of its jacket detected, temperatures of conductor and metal sheath can be calculated by software programmed. To verify the thermal model and the calculation, the emergency and cyclic current is tested. The calculation results are compared with the data of transient temperature rise tests, and it is shown that the calculation of transient tempera ture based on Runge-Kutta method is accurate. This method can be applied to the conductor temperature monito- ring, control and prediction in the practical operation of single-core cables.

关 键 词： 单芯电缆 暂态热路模型 外皮温度监测 法 暂态温度 计算 试验

领　　域： [电气工程]