Remote monitoring of partial discharge data from insulated power cables

Partial discharge (PD) diagnostics is one of the most widely used tool to assess the insulation condition of insulated power cables and which facilitates informed maintenance planning leading to the extension of the service life of such ageing assets. PD occurs with varying intensity due to circuit loading and weather conditions. Proven systems based on off-line PD diagnostics find limited application, since this method requires a circuit outage. In this study, remote controlled PC based PD monitoring system using client server technology is proposed. Continuous monitoring of cable network using the proposed system can capture sudden or gradual changes in PD activity which is often difficult in conventional PD monitoring systems which are based on spot measurement. In this system, the remote control capability using internet has been implemented to reduce the frequency of site visits which in turn reduces the cost of manpower. Relational database management system is used as a back-end server for data storage, data analysis and data management. This would help the utility to maintain insulation integrity history database which can be used for cable renewal program in the longer term. System design, testing, implementation and field measurements are discussed.