| Abstract: | This series of papers report on relay protection strategies that satisfy the demands of a strong smart grid. Thesestrategies include ultra-high-speed transient-based fault discrimination, new co-ordination principles of main andback-up protection to suit the diversification of the power network, optimal co-ordination between relay protectionand auto-reclosure to enhance robustness of the power network. There are also new development in protectionearly warning and tripping functions of protection based on wide area information.In this paper the principles, algorithms and techniques of single-ended, transient-based and ultra-high-speedprotection for EHV transmission lines, buses, DC transmission lines and faulty line selection for non-solid earthednetworks are presented. Tests show that the methods presented can determine fault characteristics with ultrahigh-speed (5 ms) and that the new principles of fault discrimination can satisfy the demand of EHV systemswithin a smart grid. |
