Thermal analysis of the influence of nonlinear, unbalanced and asymmetric loads on current conducting capacity of LV-cables

Asymmetry, unbalance and nonlinearity of loads affect the current distribution in both phase and neutral conductor cores in three phase power supply systems. Consequently, temperature distribution in the cable section which is directly related to the power dissipation is influenced. Applying a maximum insulation temperature as boundary condition, the power conducting capacity of LV-cables will substantially be affected by asymmetry, unbalance and especially nonlinearity of loads. The most relevant combinations of asymmetry, unbalance, and nonlinearity were analyzed. The temperature distribution in the cable section is thermally calculated and is subsequently simulated, using 2D finite element modelling. Finally, measurements of the cable temperature arc performed verifying the simulation results.