基于电磁-热耦合原理的三芯铠装电缆在低频输电方式下的损耗特性研究

Study on Loss Characteristics of Three Core Armored Cable under Low-Frequency Transmission Mode Based on Electromagnetic,Thermal Coupling Principle

精确分析电缆损耗特性是提高海底电缆经济性、实现深远海风电高效输送的关键问题之一。为此,该文建立三芯铠装电缆的电磁-热耦合仿真模型,研究了缆芯电流在低频输电方式下的不均匀分布特性,并以此为基础,分析IEC标准计算护套感应电压、损耗因子及载流量的误差。研究结果表明,缆芯电流密度平均值点偏离缆芯中心,偏离距离随输电频率的增大而增大,并导致IEC标准计算的护套感应电压和损耗做同向变化,当缆芯半径大于24mm时,护套损耗因子误差明显加剧;当缆芯截面积取2000mm^(2)时,分频及工频下的载流量误差分别达10%和15%左右。计算结果为合理地确定海底电缆载流量奠定了基础。

Accurately computing cable loss is one of the critical issues to improve the economics of submarine cables and realize the efficient transmission of deep-sea wind power.In this study,according to the submarine cable's actual laying conditions,a multi-physical coupling model of submarine cable is established based on the electromagnetic field and heat transfer field.This model can help to analyze the distribution of cable core current under low-frequency transmission mode.Based on this model,this paper studies induced voltage calculated by IEC standard,loss factor,and error of ampacity.The research shows that the average current density of the cable core deviates from the cable core center.The deviation distance increases with the increase of transmission frequency,which caused the sheath induced voltage and loss error calculated by IEC to change in the same direction.When the core radius is greater than 24mm,the sheath loss factor's error becomes more massive.When the cable core's cross-sectional area is 2000 mm^(2),the ampacity error under fractional frequency and industrial frequency is about 10%and 15%,respectively.The calculation results lay a foundation for reasonable determination of the current carrying capacity of submarine cables.