Simulation calculation and influence factor analysis of induced voltage of metal sheath

Abstract

The current in the core of the single-core high-voltage cable will induce the alternating magnetic field around it, and the cable metal sheath will induce the induced voltage under the action of the magnetic field. Higher induced voltage will affect the normal operation of the cable and the safety of the operations staff. In this paper, a three-dimensional corrugated aluminum sheath model is constructed according to the actual cable, and the results are compared with the two-dimensional model, in the case of horizontal laying and triangular laying, the error is within 0.009V/m, so a two-dimensional model can be used to simplify the calculation. The error between the two-dimensional model and theoretical calculation is within 0.005V/m under the two laying conditions, which verifies the correctness of the simulation value. In this paper, the effect of unbalance of current on induced voltage is analyzed. When the phase angle is unbalance, the induced voltage of other phases increases sharply. On the basis of double circuit calculation formula, the induced voltage of three circuits and four circuits is calculated by superposition method. The induced voltage of more phases can be superimposed according to this method. The intermediate distance can be appropriately increased to reduce the side phase induced voltage during four-loop laying. The results of the discussion have reference significance for cable laying in practical engineering.