DC power transmission system - has protective resistors at cable ends to attenuate AC signals arising from load-side failures

摘要

The d.c. power transmission system has protective resistors connected at one end of the transmission cable between d.c. source and the cable inner conductor, and at the other end between the load and the cable inner conductor. The resistors have values equal to the wave impedance of the cable. The resistors reduce the amplitude of any a.c. signals that find their way into the cable (e.g. owing to a failure at the load end) and which would without these resistors, be sufficient to damage the dable insulation which was only designed to withstand d.c. voltages. The protective components include an inductive element which clamps out fluctuations in the input supply.