随桥敷设高压电缆接头结构层温升与载流特性研究

Research on Temperature Rise and Current Carrying Capacity Characteristics of Bridge-along HV Cable Joint

针对随桥敷设高压电缆的特殊运行工况,开展了高环境温度对中间接头温升与电缆载流量特性影响的研究。建立了220 k V随桥敷设高压电缆中间接头结构层温度场有限元仿真模型,分析了环境温度、电缆接头防水结构、桥梁梁厢空气对流等因素对中间接头结构层温度分布与载流量特性的影响规律。结果表明:环境温度是影响电缆接头温升过程与载流量的最重要原因,当桥梁梁厢环境温度由30℃提升至50℃,电缆流量降低了18.8%。在高环境温度下,提高桥梁梁厢空气流速可以有效抑制中间接头结构层温升,提高电缆载流量。所提出的高环境温度条件下随桥敷设电缆中间接头载流量的安全域,可为全球能源互联网跨海、跨河桥梁高压电缆安全可靠运行奠定理论与实验基础。

Aimed at the special operating conditions of bridge-along HV cable,the influences of high ambient temperature on the temperature rise of cable joint and the current carrying capacity characteristics of cables are studied in this paper. A finite element simulation model for the temperature field of 220 kV bridge-along HV cable joint is established,and the influences of ambient temperature,cable joint waterproof structure and air convection in the bridge beam box on the temperature distribution of cable joint and current carrying capacity characteristics are analyzed. Results show that ambient temperature is the most important factor affecting the temperature rise process of cable joint and the current carrying capacity. When the ambient temperature in the bridge beam box increases from 30 to 50 ℃,the cable’s current carrying capacity is reduced by 18.8%. Under a high ambient temperature,increasing the air velocity in the bridge beam box can effectively suppress the temperature rise in the joint’s structural layer and improve the cable’s current carrying capacity. The safety zone of the current carrying capacity of bridge-along joint under the condition of high ambient temperature is given in this paper,which will lay a theoretical and experimental foundation for the safe and reliable operation of global energy Internet HV cables laid along sea or river bridges.