FEM modelling of faults occurred in buried power cables due to the removal of tree roots

An engineering approach to numerical modelling of power cable heating due to a line‐to‐earth short‐circuit caused by previous mechanical damages of a cable sheath and insulation is proposed in this paper. Nonlinearity of the finite element model is based on the soil thermal conductivity and heat sources as functions of temperature and time. The nonlinear transient analysis is applied to an authentic example of line‐to‐earth short‐circuit caused by a mechanical damage of the cable sheath and insulation that has arisen during the previous removal of tree roots. The represented fault occurred on 14 November 2007 in a buried 0.4 kV cable line installed in the city of Bijelo Polje, Republic of Montenegro. Also, this paper outlines a proposition of a technical report prescribing procedures for the removal of tree roots from the soil surrounding cables and for laying power cables nearby high vegetation. The proposed engineering approach is applicable to power cables of all voltage levels laid in soils with changeable moisture content.