Abstract
Power distribution system relies heavily on a vast network of medium voltage (MV) underground cables for power delivery. Condition monitoring technologies can, therefore, play a vital role in attempting to target the cables that pose the most urgent reliability concerns. Maintaining or increasing a power system's reliability at minimal cost is an important issue for most network owners. Condition monitoring gives the information needed for safe and reliable operation, replacement strategy and hence increases the system reliability. Demands for reliable power causes a growing tendency to apply different strategies in the form of condition based maintenance. Partial discharge (PD) monitoring is one of the successful diagnostic tools for accessing the insulation condition of MV cables. Data acquired by online PD measurements can help in identifying the upcoming faults in such cable networks and possibly forecast the remaining life of the insulation. This paper reviews the condition monitoring and diagnostic techniques used for underground power cables.