Ampacity calculation of the underground power cables in voluntary conditions by finite element method

Exceeding the ampacity of the underground power cables according to the depth of soil and other parameters is a problem in literature because of the risk of temperature rise and subsequently the probable material failure. This paper introduces the heat transfer mechanisms in the underground cable installations and analyzes the available solution methods of the diffusion equation by finite element method. The cable ampacity is a function of soil thermal resistively, and burial depth. Cable ampacity relationship with these parameters is investigated and the manner that they affect the current of the cable is surveyed. To do so, the commercial ANSYS software has been employed. Results show that ampacity decreases as the depth of soil or its conduction thermal resistance increases. This method gives us the criteria and a flexible approach to change the strategy on those cases which have not been pointed in cable routing standard documentary.