HVDC line protection for the proposed future HVDC systems

The paper reviews the ability of present protection systems to provide adequate protection for proposed future HVDC systems. This initial study reviews current protection systems used for DC line protection and highlights both the advantages and disadvantages of these systems including the factors that adversely influence their performance. The paper stresses the importance of local fault detection and suggests that telecommunication should, as far as possible, only be used to enhance and optimize the systems. The paper also highlights the major advantages of using the system transients to detect DC line faults in terms of security, reliability, speed of fault clearance and fault recovery as well as the drawbacks and current limitations and possible solutions. The authors finally evaluate the current protection systems and propose ways of enhancing some of the existing protection systems with local supervision and other techniques to improve their performance and capability.