Adaptive Protection Co-ordination Methods Concerning a Dedicated Operation of Large IPP Units Connected to the Transmission Grid

This paper presents advanced protection coordination methods to be applied for the integration of IPP units to the transmission grid. A typical system configuration of an IPP unit installation is considered. The protection system is also assumed to be commonly which is based on the distance protection principle. The changing network conditions and their impacts on the protection system caused by the IPP are described. Thus the topics of co-ordination of different characteristics, teleprotection schemes, distance grading and relay loadability are investigated and methods for covering their adverse impacts are given. It can be seen that only modern relay technology is not leading to a proper protection system. Only well co-ordinated and adapted protection relays will result in a system of high reliability of the IPP in-feed and in an economic benefit for the IPP investors finally.