Research Projects

Recently there has been a rising trend towards a more renewable based PowerGrid. Out of the multiple advantages that a renewable grid has, the most important is making the powergrid carbon free. Now in this endeavour, the power needs to be generated in bulk such that it can compete with conventional coal-based powerplants. To generate substantial amount of power, the capability of a system to harness more power needs to be investigated. The most important way to harness wind power is to establish offshore wind plants. The energy of the waves can be best harnessed in the middle of the ocean. This type of power generation can be best justified if proper transportation of power can be done through power cables under the sea to the land(onshore). The significance of the power cable inherently calls for a rigid power transmission network under the sea which can be highly robust and reliable. The cables used in the sea for bulk power transport, is basically different from underground cables. Moreover, another advantage of undersea power transportation is related to the asynchronous power exchange between two countries. The main aim of this project will be to develop a theoretical framework in understanding space-charge ageing of undersea cables. After a proper mathematical framework is developed, experimentation will be done to measure the actual space charge developed. The experimentation will include, accelerated ageing tests with voltage applied under both salt water and fresh water. The voltages will include high voltage AC and High Voltage DC. After experimentation, morphology-based analysis along with space charge measurement need to be done and explained based on the theoretical framework. The morphology-based analysis will be conducted on the insulation at two places. Samples will be collected from inside and outside. The inside sample will include the insulation in contact with the high voltage conductor. The outer sample will include sample in direct contact with salt water. The morphology-based test will include FTIR and EDX. This will provide us with the notion of chemical reactions happening at the two places from which the sample has been collected. The second part of the work will include the measurement of partial discharge happening in the cables under salt water and with application of HVAC. The partial discharge signals will be detected based on acoustic emissions and later analysed to understand the severity of insulation breakdown due to partial discharge. A time-frequency based analysis of acoustic partial discharge signals can help in developing non-destructive condition monitoring of undersea cable provided we can develop a signal acquisition system which can be used for undersea long power transmitting cable.