Investigations on the noise generation phenomena in the PLC system of a long HVDC line

There are several means of carrying communications of long HVDC transmission lines. However, the Power Line Carrier (PLC) still plays an important role in the operation of some long HVDC transmission lines around the world. Some uses of the PLC include teleprotection and network data transmission between the converter stations of the HVDC transmission system. Above certain operational voltages of the HVDC system, high levels of noise are experienced in the PLC during the operation. This paper describes the phenomenon that leads to the high levels of noise in the PLC systems of long HVDC lines. It further describes the methodology and experimental work that has so far been conducted in investigating these phenomena.