Sheath fault characteristics and modelling on underground power transmission cables

The paper reports on the experimental characterisation and subsequent devel opment of an electrical model for cable oversheath faults under AC voltages . The characteristics can be represented by a combination of linear resista nce and capacitance below a threshold voltage and a non-linear resistance a bove the threshold voltage. The proposed model was then incorporated into A TP (Alternative Transient Program). The simulation results clearly show sat isfactory similarity between the model and the experimental results. The de veloped electrical model may therefore be used to accurately simulate sheat h-to-earth fault conditions in buried cable systems.