复杂环境中海底电缆温度场及载流量模型研究

Analysis of submarine cable temperature field and ampacity model in complex environment

载流量是海底电缆运行调度的重要参数,受最高允许工作温度所制约,建立考虑复杂海洋环境中洋流影响的海底电缆温度场及载流量模型具有重要意义。针对传统解析法计算复杂、仅适用于特定敷设环境等问题,根据电-热-流多场耦合理论,基于有限元分析技术分别建立了埋设和铺设两种敷设方式下的高压三芯交联聚乙烯(XLPE)海底电缆温度场及载流量分析模型,并研究了洋流流速及温度对海缆载流量的影响。研究结果表明,所建模型与传统解析法相对误差在5%以内;相同环境因素下,铺设海缆稳态载流量比埋设高出200~330 A不等,且两者变化率在低流速时更灵敏,但不受洋流温度所影响;此外,短时应急载流量允许运行时间与其大小及初始缆芯温度成反比关系。

The ampacity of submarine cables is an important parameter for its operation and scheduling,which is restricted by the maximum allowable operating temperature of submarine cables.It is of great significance to establish the temperature field and ampacity model of submarine cables considering the influence of ocean currents in complex submarine environment.In view of the complicated calculation of the traditional analytical method and just suitable for specific laying environment and other problems,according to the electro-heat-flow multi-field coupling theory,based on the finite element analysis technology,the temperature field and ampacity analysis model of high-voltage three-core XLPE submarine cable under the two laying methods of burying and laying are established respectively,and studied the influence of ocean current velocity and temperature on the ampacity.The research results show that the relative error between the proposed model with the traditional analytical method is within 5%;the steady-state ampacity of the laid cable is 200~330 A higher than the buried under the same environmental factors,and the change rate of the two methods is more sensitive at low current rates,but it is not affected by the temperature of the ocean current.In addition,the allowable operating time of short-term emergency ampacity is inversely proportional to its size and initial cable core temperature.