On voltage dip propagation

Voltage dips due to faults at high-voltage level, change magnitude when they propagate to lower voltage levels. Measurements are shown to quantify this phenomenon. The measurements presented show that the remaining rms voltage increases when moving towards the load. The severe change in load current due to the drop in voltage, mitigates the voltage dip. For unbalanced dips it is shown that the positive-sequence voltage increases and the negative-sequence voltage decreases towards the load. More measurements and simulation studies are needed to confirm. and explain this behaviour. A voltage drop index is introduced as a measure of the effect of the load current on the rms voltage during a voltage dip.