复杂运行条件下交联电缆载流量研究

Experimental Research on Ampacity of Extruded Power Cable Under Complex Operating Condition

载流量是决定电力电缆经济可靠性最重要的参数。针对城市地下电力电缆电网运行条件复杂化,电缆线路载流量因素难于确定的状况,首次在国内开展了110 kV交联电缆载流量的试验研究,模拟实际条件进行了110kV交联电缆在大埋深、多回路以及在各种负荷状态等条件下的电缆载流量试验。通过试验研究,给出了不同运行条件下电缆载流量,得到了不同敷设形式、负荷状况下电缆的负荷电流、导体温度、表面温度间的关系数据,并对电缆线路载流量的主要影响因素进行了分析。通过研究得到了几种特定敷设条件下电缆载流量试验的数据,给出了电缆线路典型的外部热环境参数参考值。研究结论能够直接用于城市电网的实际运行,并能作为电缆线路设计、优化以及运行时载流量控制的指导数据。

Ampacity under nonuniform operating conditions is difficult to be exactly determined by theoretic calculation because of the limitation for the theoretic model. The experimental research of ampacity for 110 kV extruded power cable was conducted. In order to simulate the actual operating conditions, four full-size cable trenches were constructed, and different loads were also applied to the power cables. The main affecting factors of the ampacity for the power cables under uniform conditions are discussed in detail according to test results. The reference values of thermal resistance for soil and different backfills in the experimental research as well as a whole year temperature chart of the soil for test site were presented. The test data were used to determine the ampacity of the power cables in practical engineering, the measured values of thermal resistance and temperature will be used to adjust the reference operating conditions for theoretic calculation in practical.