Efficient Energy Harvesting Using Current Tranformer for Smart Grid Application

In the high voltage power lines, whenever the load increases beyond the specified limit or short circuited, the load draws more current which can damage the system or lead to accidental fires. A good protection system is necessary to avoid such accidents and to protect the components of electrical systems. Protection systems have several features like monitoring the line current, processing and actuating the circuit breakers in case of faults. Moreover in present days numerical relays are playing major role in such protection systems. The numerical relays are classified based on their applications and the type of protection needed. Self Powered relay is a special type of numerical protection relay which draws power from the measuring line currents and does not require an auxiliary power source to operate. Hence these types of relays are an ideal choice for installation even in remote locations where auxiliary supplies are not available. Furthermore, Self powered protection device is intended to be used for the selective short-circuit and earth-fault protection of feeders in secondary distribution networks and for protection of transformers in utilities and industries. In self powered device, Current transformers (CTs) are used to harvest the energy from the line currents. In this paper, the design of a transformer for effective energy harvesting method is explored.