谐波对电力电缆损耗的影响分析与计算方法

文章分析电缆运行时,电磁场与损耗关联的机理。从电磁场理论出发,结合屏蔽层感应电流的计算,基于bessel函数,推导出电缆在谐波下的电流密度分布。该过程,考虑临近效应、集肤效应对电流密度分布的影响,并推导出了相应的解析表达式。首先对两相电缆回路分析,再通过解析式的最终结构引入修正因子,将推导扩展到多相电缆情形下。其次分析缆芯损耗、金属屏蔽层损耗、绝缘损耗,并且通过多相电缆修正因子推导出电缆敷设修正因子。最终通过MATLAB软件仿真分析,将计算方法与IEC、IEEE标准进行对比,对谐波影响电缆损耗进行定性的分析,验证所提方案的正确性。

Impact Analysis and Calculation Method of the Harmonic on Power Cable Loss

s: Mechanism of the electromagnetic field associated with loss about running cable is firstly analyzed in the paper. Based on electromagnetic field theory and Bessel function, combining with calculation of induced current on cable shield, current density distribution of cable shield under harmonic is deduced. Approaching effect and skin effect on the current density distribution is considered and the corresponding analytical expression is deduced during this process. With previous analysis of two phase cable circuit, and then leading into the correction factor, the analytic expression of the final structure is extended to multiphase cable case. The core loss, metal shielding layer loss and insulation loss is analyzed after that. Multiphase cable laying correction factors are deduced by the correction factor above. Qualitative analysis results of the influence on cable harmonic loss is got on MATLAB simulation platform and the calculation method is compared with IEC and IEEE standard furthermore.