交流单芯海底电缆金属护层接地方式研究

为研究多种工况下综合考虑经济性和安全性后的交流单芯海缆金属护层最佳的接地方式,首先分析了金属护层工频感应电压、短路感应电压以及冲击感应电压的作用机理和计算方法,指出了过电压工况是制约海缆安全运行的控制条件。针对接地方式选择的经济性评估,认为长距离海缆的电容电流对海缆工频感应电压、损耗以及载流量有较大影响,需对IEC 60287的损耗计算方法进行修正以便正确计算海缆载流量,最后给出了金属护层接地方式的选择原则。

Research on Sheath Grounding Method of AC Single Core Submarine Cable

In order to analyze the grounding methods of AC single core submarine cable sheath, the principles and calculation methods of the induced voltages in normal operation condition, short circuit and impulse condition are analyzed at first.Then the impulse condition is pointed out to be the key condition to verify the operation safety of submarine cable.In addition, the economy of grounding methods should be evaluated.Since the capacitive current has a great impact on the normal induced voltage, power losses and current rating in a long submarine cable, the calculation method of power loss provided by IEC 60287 must be modified for the purpose of calculating the current rating.Finally the selection principle of grounding methods is proposed.