|Network protection distribution networks decentralised energy resources communication links IEC Communication and Substation Control Standards|
The global trends of deregulation, globalisation and privatisation have had and still have a strong impact on the electric power industry. The problems connected with the limitations of exciting energy resources, as opposed to a continuously growing world population, especially in developing and emerging countries, play and will play even more an important role in the future. Environmental matters, along with public acceptance of certain technologies e.g. energy generation from decentralised energy resources, which also have a strong political aspect, are likewise becoming increasingly significant factors. In a distribution network with high penetration of decentralised energy resources, the direction of power flow, which was clearly defined in the electrical power system without decentralised generation, changes according to the ratio of energy offered from the decentralised energy resources and the power system on the higher voltage level and the energy demand from the network costumers. However the protection systems installed in the power system are not set to manage these variable changes of direction of power flow. Because of the lack of “powerful” generators that can create a strong network, such a network characterises by a very low short circuit power, which is definitely going to affect the protection system. The protection devices implemented in the network are about to be set to match these changes. Consequently new protection concepts are necessary. In this work some idea-concepts of network protection in distribution networks with high penetration of decentralised energy resources are presented.