Research on Current Carrying Capacity Calculation of 500 kV Single-Core AC Cable Laying in Power Tunnel

Tunnel laying cable is a transmission mode with large capacity, many circuits and high reliability, which is widely used in urban power grid transmission and other occasions. Under the condition of tunnel laying, the layout of power cable has great influence on its carrying capacity (The current flowing through a cable), so it is necessary to carry out the calculation and analysis of the carrying capacity of the cable in the tunnel under different layout. Taking 500 kV (kilovolt) single-core AC (Alternating current) cable as an example, the 3D model of calculation area of 100 m tunnel cable is established by CFD method. The current load of the cable in the tunnel under different arrangement, different circuit number and different wind speed arrangement is calculated, and the distribution law of temperature field and flow field is obtained. The calculation results show that when the layout is a single variable, the vertical layout has the largest capacity. When the number of circuits is used as a single variable, the carrying current gradually decreases with the increase of the number of cable circuits. When the wind speed is used as a single variable, the current carrying capacity gradually decreases with the decrease of wind speed.