Measurement of cable switching transients in underground distribution systems

Routine operation of loadbreak elbows and disconnects to switch underground distribution power cables results in transient overvoltages. Presented are the results and analyses of field tests performed in two 24.94 kV systems where transient voltages were recorded during switching operations. Traveling wave propagation characteristics in the power cables, the influence of underground distribution system topology, and switching device arc behaviour are discussed. Conclusions are reached regarding the severity of the switching overvoltages.<
>